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  • 1.
    Almroth, Gabriel
    et al.
    Linköping University, Department of Medicine and Care, Nephrology. Linköping University, Faculty of Health Sciences.
    Axelsson, T.
    Linköping University, Department of Medicine and Care, Nephrology. Linköping University, Faculty of Health Sciences.
    Müssener, E.
    Linköping University, Department of Medicine and Care, Nephrology. Linköping University, Faculty of Health Sciences.
    Grodzinsky, Ewa
    Linköping University, Department of Medical and Health Sciences, General Practice. Linköping University, Faculty of Health Sciences.
    Midhagen, Gunnar
    Department of Clinical Microbiology and Immunology, University Hospital of Örebro, Sweden.
    Olcén, Per
    Department of Internal Medicine, Hospital of Lidköping.
    Increased Prevalence of Anti-Gliadin IgA-Antibodies with Aberrant Duodenal Histopathological Findings in Patients with IgA-Nephropathy and Related Disorders2006In: Upsala Journal of Medical Sciences, ISSN 0300-9734, E-ISSN 2000-1967, Vol. 111, no 3, p. 339-352Article in journal (Refereed)
    Abstract [en]

    Background: Antibodies present in coeliac disease may occur in IgA-nephropathy. This raises the question of food intolerance in the disease. Evidence for a true correlation between the two disorders has however been scarce.

    Design: Sera from 89 patients with IgA-nephropathy and 13 other patients with IgA deposits in the glomeruli of kidney biopsies were analysed for IgA-antibodies to gliadin, endomysium and tissue transglutaminase (92/102 patients).

    Results: Eleven out of 89 (12.4%) of the patients with IgA-nephropathy and five of the 13 others (38%) had elevated titres of IgA-antibodies to gliadin but, in all cases but one, normal IgA-antibodies to endomysium. Patients with IgA-nephropathy and elevated IgA-antibodies to gliadin had elevated total serum IgA more frequently than patients who had not (p<0.01). Two patients with IgA-nephropathy and one with Hennoch Schönlein's purpura had elevated IgA-antibodies to tissue transglutaminase.

    Small bowel biopsy in 7 out of 11 IgA-antibodies to gliadin positive patients with IgA-nephropathy was pathologic in three cases (two with Marsh I). One patient with chronic glomerulnephritis also had Marsh I.

    Conclusions: We found no increased frequency of verified coeliac disease in 89 patients with IgA-nephropathy. Two patients with IgA-nephropathy and one patient with chronic glomerulonephritis with IgA deposits in the kidney biopsy had a Marsh I histopathology. The findings suggest a possible link of celiac disease to IgA-nephropathy and a role for antibodies to food antigens in this disorder.

  • 2.
    Berglund, Torsten
    et al.
    Unit for Infectious Disease Epidemiology, Microbiology and Tumour Biology Centre, Karolinska Institute, Stockholm, Sweden and Unit for Infectious Disease Epidemiology, Swedish Institute for Infectious Disease Control, Solna, Sweden.
    Unemo, Magnus
    Department of Clinical Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Olcén, Per
    Department of Clinical Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Giesecke, Johan
    Unit for Infectious Disease Epidemiology, Microbiology and Tumour Biology Centre, Karolinska Institute, Stockholm, Sweden and Unit for Infectious Disease Epidemiology, Swedish Institute for Infectious Disease Control, Solna, Sweden.
    Fredlund, Hans
    Department of Clinical Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro, Sweden and Unit for Infectious Disease Control, Department of Clinical Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    One year of Neisseria gonorrhoeae isolates in Sweden: the prevalence study of antibiotic susceptibility shows relation to the geographic area of exposure2002In: International Journal of STD and AIDS (London), ISSN 0956-4624, E-ISSN 1758-1052, Vol. 13, no 2, p. 109-114Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to compare epidemiological data with antibiotic susceptibility patterns, so as to characterize the risk of infection with a highly resistant Neisseria gonorrhoeae strain. N. gonorrhoeae strains isolated in Sweden from February 1998 through January 1999 were tested for antibiotic susceptibility. Epidemiological data were received from each clinician reporting a case of gonorrhoea and these data were linked to the N. gonorrhoeae strains. A total of 348 N. gonorrhoeae isolates, representing 89% of all Swedish cases diagnosed during the 12-month period, were tested for antibiotic susceptibility. Of all isolates, 24% were β-lactamase-producing, and 18% had decreased susceptibility to ciprofloxacin (MIC>0.064 mg/l). All isolates were fully susceptible to ceftriaxone and spectinomycin. More than 99% of the isolates were fully susceptible to azithromycin. The antibiotic susceptibility varied with the places where patients were exposed to infection. When exposed in Asia, 63% of the isolates showed reduced susceptibility to ciprofloxacin, compared with 0-8.5% of the isolates from patients exposed in other places (RR=8.5, P<0.001). Ciprofloxacin cannot be recommended as the first choice of treatment if the place of exposure was in Asia.

  • 3. Bäckman, A
    et al.
    Lantz, P-G
    Rådström, P-G
    Olcén, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of health and environment.
    Evaluation of an extended diagnostic PCR assay for detection and verification of the common causes of bacterial meningitis in CSF and other biological samples. 1999In: Molecular and Cellular Probes, ISSN 1044-7431, E-ISSN 1095-9327, Vol. 13, p. 49-60Article in journal (Refereed)
  • 4.
    Bäckman, Anders
    et al.
    Department of Clinical Microbiology and Immunology, Örebro Medical Center Hospital, Örebro.
    Orvelid, Paula
    Department of Clinical Microbiology and Immunology, Örebro Medical Center Hospital, Örebro.
    Vazquez, Julio A.
    Servicio de Bacteriologı́ca, Centro Nacional de Microbiologı́ca, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
    Sköld, Ola
    Department of Pharmaceutical Bioscience, Biomedical Centre, Uppsala University, Uppsala.
    Olcén, Per
    Department of Clinical Microbiology and Immunology, Örebro Medical Center Hospital, Örebro.
    Complete Sequence of a β-Lactamase-Encoding Plasmid in Neisseria meningitidis2000In: Antimicrobial Agents and Chemotherapy, ISSN 0066-4804, E-ISSN 1098-6596, Vol. 44, no 1, p. 210-212Article in journal (Refereed)
    Abstract [en]

    Identical β-lactamase-encoding (TEM-1) plasmids were found in two different clinical Neisseria meningitidis strains. They were completely sequenced (5,597 bp) and designated pAB6. The plasmid is almost identical to Neisseria gonorrhoeae plasmid pJD5 (5,599 kb) and may have been picked up from a gonococcus in vivo.

  • 5.
    Clarke, S. C.
    et al.
    Scottish Meningococcus and Pneumococcus Reference Laboratory, North Glasgow University Hospitals NHS Trust, Stobhill Hospital, Scotland, UK and Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow, Scotland, UK.
    Diggle, M. A.
    Scottish Meningococcus and Pneumococcus Reference Laboratory, North Glasgow University Hospitals NHS Trust, Stobhill Hospital, Scotland, UK.
    Mölling, Paula
    National Reference Laboratory for Pathogenic Neisseria, Örebro University Hospital, Örebro, Sweden.
    Unemo, Magnus
    National Reference Laboratory for Pathogenic Neisseria, Örebro University Hospital, Örebro, Sweden.
    Olcén, Per
    National Reference Laboratory for Pathogenic Neisseria, Örebro University Hospital, Örebro, Sweden.
    Analysis of PorA variable region 3 in meningococci: implications for vaccine policy?2003In: Vaccine, ISSN 0264-410X, E-ISSN 1873-2518, Vol. 21, no 19-20, p. 2468-2473Article in journal (Refereed)
    Abstract [en]

    Outer membrane protein (OMP) vaccines are being developed against Neisseria meningitidis serogroup B which may provide protection against common circulating serotypes and serosubtypes in some countries. However, limited data is available in Europe from genosubtyping meningococci. We therefore undertook a retrospective analysis of the three main variable regions, VR1, VR2 as well as VR3, of the porA gene from N. meningitidis isolated from different countries, mainly from Scotland and Sweden. Analysis of this gene showed that, amongst 226 strains studied, there were a total of 78 different strains. No new VR1 or VR2 alleles were found but five new VR3 alleles are described. Our data indicates the importance of analysing the VR3 region of PorA in addition to VR1 and VR2 and also highlights, in general terms, the need for genosubtyping meningococci. Such analyses have major implications for the design of new meningococcal vaccines.

  • 6.
    Dahle, Charlotte
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Clinical Immunology.
    Skogh, Thomas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Rheumatology. Östergötlands Läns Landsting, Centre for Medicine, Department of Rheumatology in Östergötland.
    Åberg, A K
    Örebro.
    Jalal, A
    Örebro.
    Olcén, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology.
    Methods of choice for diagnostic antinuclear antibody (ANA) screening: Benefit of adding antigen-specific assays to immunofluorescence microscopy2004In: Journal of Autoimmunity, ISSN 0896-8411, E-ISSN 1095-9157, Vol. 22, no 3, p. 241-248Article in journal (Refereed)
    Abstract [en]

    Objectives. To evaluate and compare the performances of three enzyme-immunoassays (EIAs) and a double radial immunodiffusion (DRID) test in addition to immunofluorescence (IF) microscopy for routine laboratory screening of patient sera sent for antinuclear antibody (ANA) analysis. Methods. 3079 consecutive patient sera sent for routine testing of ANA were analysed by IF microscopy on HEp-2 cells (IF-ANA), three different ANA-EIAs, and a DRID test for antibodies against extractable nuclear antigens. The IF-ANA and DRID tests were regarded as reference methods. Results. By IF-ANA and/or DRID, 375 sera (12%) turned out ANA-positive. A further 171 sera (6%) were positive by EIA, but could not be confirmed either by IF microscopy or DRID. 32 of the 375 ANA-positive (9%) sera were negative by IF microscopy, but had precipitating antibodies against Ro/SS-A (52 and/or 60 kD). Conclusions. Different assays for ANA analysis give overlapping results to a certain extent, but are by no means interchangeable. Thus, different ANA tests reflect different aspects of these autoantibodies. The diagnostic utility of ANA testing still mainly refers to IF-microscopy and precipitin tests. IF-ANA should not be abandoned as the golden standard in clinical routine, until diagnostic and classification criteria for systemic lupus erythematosus and other systemic inflammatory autoimmune diseases have been revised. However, in addition we strongly advocate that a specific test for anti-Ro/SS-A antibodies is always included.

  • 7.
    Falk, Lars
    et al.
    a Department of Dermatology, Örebro University Hospital, Örebro, Sweden.
    Lindberg, Margret
    a Department of Dermatology, Örebro University Hospital, Örebro, Sweden.
    Jurstrand, Margaretha
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Bäckman, Anders
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Olcén, Per
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Fredlund, Hans
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Genotyping of Chlamydia trachomatis would improve contact tracing2003In: Sexually Transmitted Diseases, ISSN 0148-5717, E-ISSN 1537-4521, Vol. 30, no 3, p. 205-210Article in journal (Refereed)
    Abstract [en]

    Background: The reported number of genital Chlamydia trachomatis infections has increased 15% annually since 1997 in Sweden. Inaccurate partner notification might be one reason.

    Goal: The goals were to determine if genotyping of C trachomatis would improve partner notification and to study the duration of infection.

    Study Design: Sexual networks were constructed. C trachomatis isolates from 231 individuals attending the Örebro STD clinic during 1 year were typed by sequencing of the omp1 gene.

    Results: All individuals were traced and diagnoses were established in 30 of 161 networks. More than one genotype was seen in seven networks. The mean duration of C trachomatis infection in each network was calculated to be 23 weeks.

    Conclusion: Genotyping could be a useful tool in partner notification when there are discrepant or uncommon genotypes. Limited clinic catchment areas create information difficulties that obstruct accurate contact tracing.

  • 8.
    Forsum, Urban
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Microbiology.
    Olcén, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology.
    Skurnik, Mikael
    Diagnostic clinical bacteriology - Recent developments in the application of molecular biology tools2004In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 112, no 11-12, p. 709-712Article in journal (Refereed)
  • 9.
    Forsum, Urban
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Microbiology.
    Olcén, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology.
    Skurnik, Mikael
    Methods in molecular biology2004Book (Other academic)
    Abstract [en]

    An accessible introduction to how genomics has and will provide novel methods for bacterial investigation and advance our understanding and knowledge of bacterial pathogenicity. The authors critically evaluate the applications of genomics to diagnostic bacteriology, highlighting both current and likely future uses, describing real-time PCR methods, and outlining the promise of microarrays in clinical bacteriology. Their discussion examines in detail genomic approaches to antibacterial discovery, the nature of pathogenicity, the discovery of new pathogens, the exploration of the concept of clonality in bacteria, and bacterial taxonomics.

  • 10.
    Garpenholt, Ö
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of health and environment.
    Hugosson, S
    Fredlund, H
    Bodin, L
    Olcén, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of health and environment.
    Epiglottitis in Sweden before and after introduction of vaccination against Haemophilus influenzae type b.1999In: The Pediatric Infectious Disease Journal, ISSN 0891-3668, E-ISSN 1532-0987, Vol. 18, p. 490-493Article in journal (Refereed)
  • 11.
    Garpenholt, Ö.
    et al.
    Department of Clinical Microbiology, Sec. of Infect. Disease Epidemiology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Hugosson, S.
    Department of Clinical Microbiology, Sec. of Infect. Disease Epidemiology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Fredlund, Hans
    Department of Clinical Microbiology, Sec. of Infect. Disease Epidemiology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Giesecke, J.
    Department of Clinical Microbiology, Sec. of Infect. Disease Epidemiology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Olcén, Per
    Department of Clinical Microbiology, Sec. of Infect. Disease Epidemiology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Invasive disease due to Haemophilus influenzae type b during the first six years of general vaccination of Swedish children2000In: Acta Paediatrica, ISSN 0803-5253, E-ISSN 1651-2227, Vol. 89, no 4, p. 471-474Article in journal (Refereed)
    Abstract [en]

    Since 1992-93 vaccination against Haemophilus influenzae type b (Hib) has been included in the general Swedish childhood vaccination programme. The aim of the present study is to describe the epidemiology, identify and describe vaccine failures and calculate vaccine effectiveness during the first 6 y after introduction of vaccination against Hib. Laboratory reports of blood and cerebrospinal isolates to the Swedish Institute for Infectious Disease Control were used as the source for identifying the patients. Additional information was subsequently obtained from physicians and parents of children who had developed the disease during the study period. Vaccine failures were identified and vaccine effectiveness calculated. During the study period, 152 cases of invasive H. influenzae were identified in the age group 0-14 y. During the 6-y period, 6 true vaccine failures, 6 apparent vaccine failures and 1 possible vaccine failure were found in nearly two million vaccinated child-years. The effectiveness of the Hib vaccination in the birth cohort of children 1993 to 1997 in Sweden was calculated to be 96.1% (95% confidence interval 94.2-97.5). The study supports earlier studies from several countries that conjugated Hib vaccination introduced in general childhood vaccination programs is effective and substantially decreases suffering from invasive Hib diseases.

  • 12.
    Gharizadeh, Baback
    et al.
    Department of Biotechnology, Stockholm Center for Physics, Astronomy and Biotechnology, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Ohlin, Andreas
    Department of Pediatrics, Örebro University Hospital, Örebro, Sweden.
    Mölling, Paula
    Department of Clinical Microbiology, Örebro University Hospital, Sweden.
    Bäckman, Anders
    Department of Clinical Microbiology, Örebro University Hospital, Sweden.
    Amini, Bahram
    Department of Biotechnology, Stockholm Center for Physics, Astronomy and Biotechnology, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Olcén, Per
    Department of Clinical Microbiology, Örebro University Hospital, Sweden.
    Nyrén, Pål
    Department of Biotechnology, Stockholm Center for Physics, Astronomy and Biotechnology, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Multiple group-specific sequencing primers for reliable and rapid DNA sequencing2003In: Molecular and Cellular Probes, ISSN 1044-7431, E-ISSN 1095-9327, Vol. 17, no 4, p. 203-210Article in journal (Refereed)
    Abstract [en]

    Pyrosequencing™ technology is a bioluminometric DNA sequencing method that employs a cascade of four enzymes to deliver sequence signals. To date this technology has been limited to the sequencing of short stretches of DNA. As an improvement to this technique, we have introduced a bacterial group-specific, multiple sequencing primer approach that circumvents sequencing of less informative semi-conservative regions of the 16S rRNA gene. This new approach is suitable for challenging templates, improving sequence data quality, avoiding sequencing of non-specific amplification products, lessening sequencing time, and moreover, this strategy should open the way for many new applications in the future. The group-specific, multiple sequencing primers can be applied in the Sanger dideoxy sequencing method as well. In addition, we have improved the chemistry of the Pyrosequencing system enabling sequencing of longer stretches of DNA, which allows numerous new applications.

  • 13.
    Grodzinsky, Ewa
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Clinical Immunology. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Immunology and Transfusion Medicine.
    Ivarsson, A
    Juto, P
    Olcén, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of health and environment.
    Fälth-Magnusson, Karin
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Pediatrics. Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Barn.
    Persson, L.Å.
    Hernell, O
    New automated immunoassay measuring immunoglobulin A antigliadin antibodies for prediction of celiac disease in childhood.2001In: Clinical and Diagnostic Laboratory Immunology, ISSN 1071-412X, Vol. 8, p. 564-570Article in journal (Refereed)
  • 14.
    Hansson, L. Å.
    et al.
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden.
    Silfverdal, Sven-Arne
    Departments of Paediatrics, Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Strömbäck, L.
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden.
    Erling, V.
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden.
    Zaman, S.
    Department of Social and Preventive Pediatrics, King Edward Medical College, Lahore, Pakistan.
    Olcén, Per
    Departments of Paediatrics, Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Telemo, E.
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden.
    The immunological role of breast feeding2001In: Pediatric Allergy and Immunology, ISSN 0905-6157, E-ISSN 1399-3038, Vol. 12, no s14, p. 15-19Article in journal (Refereed)
    Abstract [en]

    No abstract available.

  • 15.
    Heikkinen, Terho
    et al.
    Turku University Hospital.
    Booy, Robert
    University of London.
    Campins, Magda
    Hospital Universitari Vall d’Hebron.
    Finn, Adam
    University of Bristol.
    Olcén, Per
    Örebro University Hospital.
    Peltola, Heikki
    Helsinki University Central Hospital.
    Rodrigo, Carlos
    University Hospital "Germans Trias I Pujol".
    Schmitt, Heinz-Josef
    Johannes Gutenberg University.
    Schumacher, Fabian
    Università degli Studi di Brescia.
    Teo, Stephen
    University of London.
    Weil-Olivier, Catherine
    Hôpital Louis Mourier.
    Schould healthy children be vaccinated against influenza?2006In: European Journal of Pediatrics, ISSN 0340-6199, E-ISSN 1432-1076, Vol. 165, no 4, p. 223-228Article in journal (Refereed)
    Abstract [en]

          Influenza is often regarded as an illness of the elderly portion of the population because most of the excess mortality associated with influenza epidemics occurs in that age group. However, evidence derived from a large number of clinical studies carried out in different countries and various settings has clearly demonstrated that the burden of influenza is also substantial in children. The attack rates of influenza during annual epidemics are consistently highest in children, and young children are hospitalized for influenza-related illnesses at rates comparable to those for adults with high-risk conditions. Especially among children younger than 3 years of age, influenza frequently predisposes the patient to bacterial complications such as acute otitis media. Children also serve as the main transmitters of influenza in the community. A safe and effective vaccine against influenza has been available for decades, but the vaccine is rarely used even for children with high-risk conditions. Despite several existing problems related to influenza vaccination of children, the current evidence indicates that the advantages of vaccinating young children would clearly outweigh the disadvantages. Considering the total burden of influenza in children, children younger than 3 years of age should be regarded as a high-risk group for influenza, analogously with the age-based definition of high risk among persons 65 years of age or older. Annual influenza vaccination should be recommended to all children from 6 months to 3 years of age.

  • 16.
    Hugosson, Svante
    et al.
    Departments of Otorhinolaryngology, Örebro Medical Center Hospital, Örebro, Sweden.
    Silfverdal, Sven-Arne
    Departments of Paediatrics, Örebro Medical Center Hospital, Örebro, Sweden.
    Garpenholt, Örjan
    Departments of Clinical Microbiology and Immunology, Örebro Medical Center Hospital, Örebro, Sweden.
    Esbjörner, Elisabeth
    Departments of Paediatrics, Örebro Medical Center Hospital, Örebro, Sweden.
    Lindquist, Bo
    Departments of Paediatrics, Örebro Medical Center Hospital, Örebro, Sweden.
    Vikerfors, Thomas
    Departments of Infectious Diseases, Örebro Medical Center Hospital, Örebro, Sweden.
    Werner, Bo
    Departments of Community Medicine and Public Health, Örebro Medical Center Hospital, Öebro, Sweden.
    Olcén, Per
    Departments of Clinical Microbiology and Immunology, Örebro Medical Center Hospital, Örebro, Sweden.
    Invasive Haemophilus influenzae Disease: Epidemiology and Clinical Spectrum Before Large-scale H. influenzae Type b Vaccination1995In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 27, no 1, p. 63-67Article in journal (Refereed)
    Abstract [en]

    In a prospective study between January 1987 and December 1992, 103 patients with invasive Haemophilus influenzae (Hi) infection were identified in a well-defined population before large-scale Haemophilus influenzae type b (Hib) vaccination was introduced. The incidence (cases/100,000/year) of invasive Hi infection was 5.9 for the whole population, 55 for children 0-4 years old and as high as 2.8 for adults. Hib was the predominant cause of the infection (83 cases) in children but, in adults, 13/39 (30%) cases were caused by non-typable Hi and 6/39 (19%) by Hi serotype f. Three patients (3%) died and 6 (5.8%) suffered a permanent sequel from the infection. All patients with such a sequel had invasive Hib infection. No significant difference between patients 0-6 years old and matched controls regarding the frequency of subnormal serum levels of immunoglobulins was found.

  • 17.
    Hägglöf, Kristoffer
    et al.
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Lindberg, Per Olov
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Verified feasibility of structured multicommodity flow solutionsManuscript (preprint) (Other academic)
    Abstract [en]

    This paper introduces a new approach for verifying feasibility for multicommodity flow problems, MFP:s for short. This feasibility problem priginates in a new solution method for the convex MFP based on the solution of the dual convex MFP, where optimality is demonstrated by showing that a given solution to the dual convex MFP is feasible for the convex MFP and hence optimal. In this paper a brief description of the MFP and the structure of its solutions are given. Furthermore, a distance minimizing method, based on simplicial decomposition, is described and used to efficiently verify feasibility and hence demonstrate optimality. The method is applied to convex MFP:s arizing in a traffic assignment setting.

  • 18.
    Issa, Mohamed
    et al.
    Department of Microbiology and Parasitology, College of Medicine, Juba University, Sudan and Reference Laboratory of Meningitis, Department of Bacteriology, National Health Laboratory, Khartoum, Sudan.
    Mölling, Paula
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Bäckman, Anders
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Unemo, Magnus
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Sulaiman, Nageeb
    Reference Laboratory of Meningitis, Department of Bacteriology, National Health Laboratory, Khartoum, Sudan.
    Olcén, Per
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    PCR of Cerebrospinal Fluid for Diagnosis of Bacterial Meningitis During Meningococcal Epidemics: an Example from Sudan2003In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 35, no 10, p. 719-723Article in journal (Refereed)
    Abstract [en]

    Meningococcal disease is feared due to its rapid progression and high case fatality rate, especially in the African meningitis belt, where epidemics of meningococcal meningitis appear cyclically. Culture, direct microscopy and antigen detection are the basic methods for diagnosis and species identification of bacterial meningitis. These methods are known to have limitations, especially in developing countries. The aim of the present study was to document the application of PCR technology for the diagnosis of bacterial meningitis in cerebrospinal fluid (CSF) samples (n = 52) collected during epidemics in Sudan. In the application of PCR for detection of the causative agent of bacterial meningitis (based on the 16S rRNA gene), bacterial DNA was identified in 49 samples. Common bacterial species causing bacterial meningitis could be detected in 31 of the CSF samples (27 meningococci), while 18 contained DNA, mainly from normally contaminating bacteria. A specific PCR for group A meningococci (based on the sacC gene) was positive in 27 of the CSF samples. The results show that PCR technology is a sharpedged tool for confirmation of a diagnosis of meningococcal meningitis and for obtaining a direct genogrouping of group A meningococci in CSF. It is important to stress the use of direct and specific PCRs to avoid interference by contaminating bacteria, a great problem in samples from areas in the meningitis belt.

  • 19.
    Issa, Mohamed
    et al.
    Dept. of Microbiology/Parasitology, College of Medicine, Juba University, Juba, Sudan and Reference Laboratory for Meningitis, Department of Bacteriology, National Health Laboratory, Khartoum, Sudan.
    Mölling, Paula
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Unemo, Magnus
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Bäckman, Anders
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Mosaad, Mohamed
    Reference Laboratory for Meningitis, Department of Bacteriology, National Health Laboratory, Khartoum, Sudan.
    Sulaiman, Nageeb
    Reference Laboratory for Meningitis, Department of Bacteriology, National Health Laboratory, Khartoum, Sudan.
    Olcén, Per
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Neisseria meningitidis serogroup W-135 isolated from healthy carriers and patients in Sudan after the Hajj in 20002003In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 35, no 4, p. 230-233Article in journal (Refereed)
    Abstract [en]

    The first epidemic in the world of meningococcal disease due to serogroup W-135 was reported during the Hajj in 2000, with subsequent spread. The aims of the present study were to investigate whether the Hajj 2000 Neisseria meningitidis serogroup W-135 had also been carried to Sudan in the eastern part of the African meningitis belt, by examining healthy Sudanese pilgrims (Hajj 2000) and members of their families, and whether the strain was causing meningitis. The phenotypic character of W-135 meningococci from Sudanese carriers (n = 5) and patients (n = 2) 1 y later was similar to W-135 strains associated with Hajj 2000. The present study, using the combination of the 2 molecular techniques; sequencing of the porA gene for variable regions (VR1, VR2 and VR3) and pulsed-field gel electrophoresis of the entire genome (using SpeI and NheI), shows that the Hajj 2000 serogroup W-135 clone (P1.5,2,36-2 of the ET-37 complex) most probably was introduced into Sudan, by pilgrims returning from the Hajj 2000. This strain has not been diagnosed before in Sudan. Close epidemiological surveillance is required to identify a possible new emerging meningitis epidemic.

  • 20.
    Jacobsson, Susanne
    et al.
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Issa, Mohamed
    Reference Laboratory of Meningitis, Department of Bacteriology, National Health Laboratory, Khartoum, Sudan and Department of Microbiology and Parasitology, College of Medicine, Juba University, Sudan.
    Unemo, Magnus
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Bäckman, Anders
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Mölling, Paula
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Sulaiman, Nageeb
    Reference Laboratory of Meningitis, Department of Bacteriology, National Health Laboratory, Khartoum, Sudan.
    Olcén, Per
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Molecular characterisation of group A Neisseria meningitidis isolated in Sudan 1985–20012003In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 111, no 11, p. 1060-1066Article in journal (Refereed)
    Abstract [en]

    A total of 33 group A Neisseria meningitidis (Mc) isolates, collected in Sudan between 1985 and 2001, were studied in order to describe the changes over time in a country within the meningitis belt of Africa. The isolates were characterised by traditional phenotypic methods (serogrouping, serotyping, serosubtyping and antibiogram) and molecular techniques (genosubtyping, pulsed-field gel electrophoresis [PFGE] with restriction endonucleases SpeI and NheI, and multilocus sequence typing [MLST]). Three clones of group A Mc were identified: one before 1988 (sulphadiazine sensitive, serotype 4, genosubtype P1.7,13-1,35-1, sequence type 4 [ST-4]); another during and after the 1988 epidemic (sulphadiazine resistant, serotype 4, genosubtype P1.20,9,35-1, ST-5); and a third causing the 1999 epidemic (sulphadiazine resistant, serotype 4, genosubtype P1.20,9,35-1, ST-7). The first clone showed major differences compared to the other two. The second and third clones had many similarities with differences in only a single gene (pgm) in the MLST (47 of the 450 bp) but significant other differences according to the PFGE patterns. Within the clones, genosubtyping and MLST gave identical information (except one base substitution in the aroE gene in one isolate). However, the PFGE patterns showed changes over time within the clones, where SpeI revealed somewhat more diversity than NheI.

  • 21.
    Jacobsson, Susanne
    et al.
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Thulin, Sara
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Mölling, Paula
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Unemo, Magnus
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Comanducci, Maurizio
    IRIS, Chiron srl, Siena, Italy.
    Rappuoli, Rino
    IRIS, Chiron srl, Siena, Italy.
    Olcén, Per
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Sequence constancies and variations in genes encoding three new meningococcal vaccine candidate antigens2006In: Vaccine, ISSN 0264-410X, E-ISSN 1873-2518, Vol. 24, no 12, p. 2161-2168Article in journal (Refereed)
    Abstract [en]

    By the strategy “reverse vaccinology” a number of new antigens have been identified in Neisseria meningitidis, which are potential candidates for a highly needed broad-spectrum meningococcal vaccine. In the present study we examined the prevalence, sequence constancies and variations of the genes encoding three of these new antigens designated, genome-derived neisserial antigen (GNA) 1870, GNA1946 and GNA2132. All three genes were present in all N. meningitidis isolates tested. Concerning gna1870, three major variants of the gene sequences and deduced amino acid sequences were identified and 56% of the deduced amino acids were conserved in all isolates. In gna1946, 98% of the deduced amino acids were conserved and in gna2132, 54% of the deduced amino acids were conserved. Based on gene prevalence and conservation, all three antigens are promising candidates for an effective meningococcal vaccine against all N. meningitidis irrespective of serogroup.

  • 22.
    Jurstrand, Margaretha
    et al.
    Department of Clinical Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro.
    Falk, Lars
    Outpatient Sexually Transmitted Disease Clinic, Department of Dermatovenereology, Örebro Medical Centre Hospital, Örebro.
    Fredlund, Hans
    Department of Clinical Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro.
    Lindberg, Margaret
    Outpatient Sexually Transmitted Disease Clinic, Department of Dermatovenereology, Örebro Medical Centre Hospital, Örebro.
    Olcén, Per
    Department of Clinical Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro.
    Andersson, Sören
    Department of Clinical Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro.
    Persson, Kenneth
    Department of Clinical Microbiology, Malmö University Hospital, Malmö.
    Albert, Jan
    Division of Virology, Department of Microbiology, Pathology and Immunology, Karolinska Institutet, Huddinge University Hospital, Huddinge/Stockholm, Sweden.
    Bäckman, Anders
    Department of Clinical Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro.
    Characterization of Chlamydia trachomatis omp1 genotypes among sexually transmitted sisease patients in Sweden2001In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 39, no 11, p. 3915-3919Article in journal (Refereed)
    Abstract [en]

    A method for detection and genotyping of genital Chlamydia trachomatis infections based on omp1 gene amplification and sequencing was developed. DNA was extracted from urogenital or urine samples using a Chelex-based method, and an approximately 1,100-bp-long fragment from the omp1 gene was directly amplified and sequenced. Genotyping was performed by BLAST similarity search, and phylogenetic tree analysis was used to illustrate the evolutionary relationships between clinical isolates and reference strains. The method was used to determine the genotypes ofC. trachomatis in 237 positive urogenital and/or urine specimens collected at a Swedish sexually transmitted disease clinic during 1 year. The most common genotypes corresponded to serotypes E (47%) and F (17%). The omp1 gene was highly conserved for genotype E (106 of 112 samples without any mutation) and F (41 of 42 samples without any mutation) strains but appear slightly less conserved for genotypes G (n = 6) and H (n = 6), where the sequences displayed one to four nucleotide substitutions relative to the reference sequence. Genotyping of samples collected at the follow-up visit indicated that two patients had become reinfected, while three other patients suffered treatment failure or reinfection. One woman appeared to have a mixed infection with two different C. trachomatis strains. Thisomp1 genotyping method had a high reproducibility and could be used for epidemiological characterization of sexually transmitted Chlamydia infections.

  • 23.
    Midhagen, Gunnar
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Gastroenterology and Hepatology . Linköping University, Faculty of Health Sciences.
    Åberg, A-K
    Department of Clinical Microbiology and Immunology, Örebro University Hospital, Örebro.
    Olcén, Per
    Department of Clinical Microbiology and Immunology, Örebro University Hospital, Örebro.
    Järnerot, G.
    Department of Medicine, Örebro University Hospital, Örebro.
    Valdimarsson, T.
    Dahlbom, I.
    Pharmacia Diagnostics, Uppsala.
    Hansson, T.
    Pharmacia Diagnostics, Uppsala, and Department of Medicine at Karolinska Hospital, Karolinska Institutet, Stockholm, Sweden.
    Ström, Magnus
    Linköping University, Department of Clinical and Experimental Medicine, Gastroenterology and Hepatology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Medicine, Department of Endocrinology and Gastroenterology UHL.
    Antibody levels in adult patients with coeliac disease during gluten free diet a rapid initial decrease of clinical importance2004In: Journal of Internal Medicine, ISSN 0954-6820, Vol. 256, no 6, p. 519-524Article in journal (Refereed)
    Abstract [en]

    Objective. Analysis of antibodies against tissue transglutaminase (tTG) has been shown valuable in the diagnosis of coeliac disease (CD) but how quickly serum titres decrease after introduction of a gluten-free diet (GFD) is not known in adults. CD is a well-recognized disorder amongst the general population and many persons try a GFD for fairly vague symptoms before they seek medical advice. Therefore, it is important to determine the time that the serologic tests remain predictive of the disease after the introduction of a GFD.

    Methods. Sera were taken from 22 consecutively biopsy-proven adult patients with CD in connection with the diagnostic biopsy. The patients were followed for 1 year and sera were taken after 1, 3, 6 and 12 months after start of a GFD. Sera were stored at −20 °C and analysed for IgA antibodies against gliadin, endomysium and two different commercial tTG assays based on recombinant human tTG (tTGrh) and guinea-pig liver (tTGgp).

    Results. Twenty patients could be followed during GFD and all antibody titres fell sharply within 1 month after introduction of a GFD and continued to decline during the survey interval. Thirty days after beginning the diet only 58, 84, 74 and 53% of all patients had positive antibody levels of tTGrh, tTGgp, EmA and AGA respectively.

    Conclusions. As the antibodies used to confirm the diagnosis of CD fall rapidly and continue to decline following the introduction of a GFD, it is important that health care providers carefully inquire about the possibility of self-prescribed diets before patients sought medical attention.

  • 24. Muyldermans, G
    et al.
    Soetens, O
    Antoine, M
    Bruisten, S
    Vincart, B
    Doucet-Populaire, F
    Fry, NK
    Olcén, Per
    University Hospital, Örebro.
    Scheftel, JM
    Senterre, JM
    van der Zee, A
    Riffelmann, M
    Piérard, D
    Lauwers, S
    External quality assessment for molecular detection of Bordetella pertussis in European laboratories.2005In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 43, no 1, p. 30-35Article in journal (Refereed)
    Abstract [en]

    Although the PCR for the detection of Bordetella pertussis is routinely performed in diagnostic laboratories, no quality assessment program has so far been described. We report on the results obtained with two external quality assessment proficiency panels sent to European laboratories. The first proficiency panel contained a series of dilutions of three previously characterized B. pertussis clinical isolates and two negative controls. No false-positive results were reported by six laboratories providing seven data sets. The reported limits of detection of the three B. pertussis strains varied between 4 and 4,000, 9 and 9,000, and 3 and 30,000 CFU/ml, respectively. The second proficiency panel, composed of a series of dilutions of reference strains of B. pertussis, B. holmesii, B. hinzii, and B. bronchiseptica, as well as negative controls, was sent to nine laboratories. One laboratory reported a negative result for a sample and reported a B. parapertussis-positive sample to be positive for B. pertussis. By using the B. pertussis-specific target gene pertactin, one laboratory detected B. pertussis with 100% specificity. All other laboratories, which used IS481-based assays, reported positive results for the samples containing B. holmesii and B. bronchiseptica, species that have occasionally been recovered from human respiratory samples. These data show that the choice of the target gene is particularly critical for the species specificity of B. pertussis PCR assays.

  • 25.
    Mölling, P
    et al.
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology & Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Unemo, Magnus
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology & Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Bäckman, Anders
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology & Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Olcén, Per
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology & Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Genosubtyping by sequencing group A, B and C meningococci: a tool for epidemiological studies of epidemics, clusters and sporadic cases2000In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 108, no 7-8, p. 509-516Article in journal (Refereed)
    Abstract [en]

    Genosubtyping, by sequencing variable regions (VRs) 1, 2 and 3 of the porA gene, was evaluated as a tool to detect clonality of isolates in meningococcal epidemics in Africa and clusters of disease in Sweden. All 63 examined meningococcal isolates were successfully genosubtyped. The isolates belonging to group A type 4 with genosubtype P1.20,9,35a showed little heterogeneity in African epidemics in 1988 and onwards. In Sweden, two meningococcal clones of group B type 15, with genosubtypes P1.7,16,35 and P1.7,16f,35, dominated during two clusters of meningococcal disease in 1995–96 and in sporadic cases thereafter. The characterisation of group C meningococci isolated during 1992 in Sweden indicated a cluster (type 2a with genosubtype P1.5a,10d,36b) connected with a discotheque visit. Two variants of VR2 (10p and 25b), not previously described, were found among the examined isolates. Nucleotide sequence analysis of VRs in the porA gene proved a valuable epidemiological tool since almost all isolates could be genosubtyped, in contrast to the phenotypic methods presently used.

  • 26.
    Mölling, Paula
    et al.
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology & Immunology, Örebro Medical Centre Hospital,Örebro, Sweden.
    Bäckman, Anders
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology & Immunology, Örebro Medical Centre Hospital,Örebro, Sweden.
    Olcén, Per
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology & Immunology, Örebro Medical Centre Hospital,Örebro, Sweden.
    Fredlund, Hans
    National Reference Laboratory for Pathogenic Neisseria and Unit for Infectious Disease Control, Department of Clinical Microbiology & Immunology, Örebro Medical Centre Hospital,Örebro, Sweden .
    Comparison of Serogroup W-135 Meningococci Isolated in Sweden during a 23-Year Period and Those Associated with a Recent Hajj Pilgrimag2001In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 39, no 7, p. 2695-2699Article in journal (Refereed)
    Abstract [en]

    An outbreak of serogroup W-135 meningococcal disease was reported among pilgrims returning from the annual hajj (pilgrimage to Mecca) in mid-March 2000. Molecular characterization was used to investigate the similarity of the hajj-associated W-135 strains with those isolated in Sweden during a 23-year period (1978 to 2000). The same hajj-associated genosubtype, genosubtype P1.5,2,36b, has been documented in Sweden since 1979, while pulsed-field gel electrophoresis and the sulfadiazine resistance of the W-135 isolates indicated that the outbreak was probably due to a new clone of W-135 meningococci.

  • 27.
    Mölling, Paula
    et al.
    National Reference Laboratory for Pathogenic Neisseria at the Department of Clinical Microbiology & Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Jacobsson, Susanne
    National Reference Laboratory for Pathogenic Neisseria at the Department of Clinical Microbiology & Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Bäckman, Anders
    National Reference Laboratory for Pathogenic Neisseria at the Department of Clinical Microbiology & Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Olcén, Per
    National Reference Laboratory for Pathogenic Neisseria at the Department of Clinical Microbiology & Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Direct and Rapid Identification and Genogrouping of Meningococci and porA Amplification by LightCycler PCR2002In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 40, no 12, p. 4531-4535Article in journal (Refereed)
    Abstract [en]

    Invasive meningococcal infections are usually diagnosed by culture. This approach is far from optimal due to, e.g., treatment with precollection antibiotics. Molecular-genetics methods are therefore recognized as important tools for optimal laboratory confirmation of meningococcal infections as well as characterization of meningococci (Mc). The aims of the present study were to develop real-time PCRs for identification and genogrouping (A, B, C, Y, and W-135) of Mc and porA amplification that further can be used for subsequent genosubtyping. In a first run Mc were identified. In a second run they were genogrouped and porA genes were amplified. All the Mc isolates (n = 71) but one and cerebrospinal fluid samples (n = 11) tested gave the expected positive results. The specificity, inter- and intra-assay variations, and effects of different amounts of DNA on the melting temperatures were also explored. The LightCycler PCR system was found to effectively detect and characterize Mc in a few hours. This testing, including the DNA sequencing of the porA gene to reveal the genosubtype, does not take more than a working day, and the results can be compared to those from culturing with phenotypic analysis, which takes at least a few days.

  • 28.
    Nicolas, P.
    et al.
    WHO Collaborating Centre for Reference and Research on Meningococci.
    Ait M'Barek, N.
    Institut National d'Hygiène, Rabat, Morocco .
    Al-Awaidy, S.
    Department of Surveillance & Disease Control, Muscat.
    Al Busaidy, S.
    Central Public Health Laboratory, Muscat.
    Sulaiman, N.
    National Health Laboratory, Khartoum, Sudan.
    Issa, M.
    National Health Laboratory, Khartoum, Sudan.
    Mahjour, J.
    Epidemiologie et lutte contre les maladies, Ministère de la Santé, Rabat, Morocco.
    Mölling, Paula
    National Reference Laboratory for Pathogenic Neisseria, University Hospital, Örebro, Sweden.
    Caugant, D. A.
    WHO Collaborating Centre for Reference and Research on Meningococci, Norwegian Institute of Public Health, Oslo.
    Olcén, Per
    National Reference Laboratory for Pathogenic Neisseria, University Hospital, Örebro, Sweden.
    Santamaria, M.
    Communicable Diseases Surveillance and Response, WHO, Geneva, Switzerland.
    Pharyngeal carriage of serogroup W135 Neisseria meningitidis in Hajjees and their family contacts in Morocco, Oman and Sudan2005In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 113, no 3, p. 182-186Article in journal (Refereed)
    Abstract [en]

    In 2000 the global outbreak that began in Saudi Arabia was caused by a W135:2a:P1.5,2 strain of Neisseria meningitidis belonging to the ET-37 complex and to ST-11. There was concern that introduction of this epidemic clone (EC) might lead to a wave of outbreaks in the African meningitis belt. The WHO therefore initiated studies of meningococcal carriage among pilgrims and their family contacts in Morocco, Oman and Sudan, 3 to 12 months after the Hajj 2000. In Morocco, 1186 persons were swabbed 3 times. Ninety-five meningococcal strains were isolated from 2.7% of the specimens. Pulsed-field gel electrophoresis showed that 32 (33.6%) were identical with the EC. In Sudan, 5 strains identical with the EC were obtained after sampling 285 persons. In Oman, among 18 meningococcal strains isolated from 399 subjects, 11 (61.1%) belonged to the EC. The important pharyngeal carriage of W135 (EC) and its role in the 2001–2002 outbreaks in Burkina Faso argues for the necessity of reinforcing surveillance, and adapting and planning responses in Africa and the Middle East using the most appropriate vaccine.

  • 29.
    Olcén, Per
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of health and environment.
    Fredlund, Hans
    Linköping University, Faculty of Health Sciences. Linköping University, Department of health and environment.
    Isolation, culture, and identification of meningococci from clinical specimens.2001In: Renal Cancer : Methods and Protocols / [ed] Jack H Mydlo, Linköping: Linköpings universitet , 2001, p. -403Chapter in book (Other academic)
    Abstract [en]

    Because renal cancer can be managed successfully only when localized, there is a great need to develop new treatments for patients with advanced or metastatic disease. In Renal Cancer: Methods and Protocols, Jack H. Mydlo, MD, and a panel of leading clinicians and researchers review every aspect of the latest surgical, medical, and immunological therapies that can be used in the diagnosis and treatment of renal cancer. These broadly experienced investigators also present a practical account of their best basic research methods, including the use of reverse transcriptase PCR combined with genomic hybridization, cadherin, and metalloproteinase expression to reveal important factors in the detection, staging, aggressiveness, and treatment of this disease. Gene therapy, the generation of monoclonal antibodies, and the use of interferon alpha, GM-CSF, and IL-6 are also discussed. In vivo assays are provided for analyzing angiogenesis, anti-angiogenesis, and general renal tumor biology as a prelude to human clinical trials.  Comprehensive and pioneering, Renal Cancer: Methods and Protocols offers urologists, medical oncologists, laboratory investigators, and pathologists a practical collection of  the major cutting-edge techniques and therapies for renal cancer today, together with a view of the highly promising future of gene therapy.

  • 30.
    Olcén, Per
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine.
    Gustavsson, Harald
    7-åring avled efter luftvägsinfektion - DNA-analys visade pneumokocker.2003In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 100, p. 1048-1049Article in journal (Other academic)
  • 31.
    Orvelid, Paula
    et al.
    Department of Clinical Microbiology and Immunology, Örebro Medical Center Hospital, Örebro, Sweden.
    Bäckman, Anders
    Department of Clinical Microbiology and Immunology, Örebro Medical Center Hospital, Örebro, Sweden.
    Olcén, Per
    Department of Clinical Microbiology and Immunology, Örebro Medical Center Hospital, Örebro, Sweden.
    PCR Identification of the Group A Neisseria Meningitidis Gene in Cerebrospinal Fluid1999In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 31, no 5, p. 481-483Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to develop a PCR method for direct identification of Neisseria meningitidis serogroup A in cerebrospinal fluid. The assay makes use of unique sites within the gene cassette responsible for expression of the (α1→6)-linked N-acetyl-D-mannosamine-1-phosphate serogroup A capsule. A total of 67 different N. meningitidis strains and 12 clinical samples of CSF, culture positive for N. meningitidis, were examined. All the strains and samples of N. meningitidis serogroup A were correctly identified by an amplified PCR product of 519 bp. The PCR method for identification is specific for the group A gene of N. meningitidis. The assay may contribute to reducing recurrent, devastating epidemics of meningococcal infection by providing a diagnostic tool for grouping in developing countries where problems with false negative cultures are common and vaccination against serogroup A meningococci may be required.

  • 32.
    Riesbeck, Kristian
    et al.
    Department of Medical Microbiology, Malmö University Hospital, Lund University, Malmö.
    Mölling-Orvelid, Paula
    Department of Clinical Microbiology, Örebro Medical Centre Hospital, Örebro,Sweden .
    Fredlund, Hans
    Department of Clinical Microbiology, Örebro Medical Centre Hospital, Örebro,Sweden .
    Olcén, Per
    Department of Clinical Microbiology, Örebro Medical Centre Hospital, Örebro,Sweden .
    Long-Term Persistence of a Discotheque-Associated Invasive Neisseria meningitidis Group C Strain as Proven by Pulsed-Field Gel Electrophoresis and porA Gene Sequencin2000In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 38, no 4, p. 1638-1640Article in journal (Refereed)
    Abstract [en]

    A cluster of a Neisseria meningitidis serogroup C strain causing invasive disease was investigated. Five out of seven cases were associated with a particular discotheque. The strains were indistinguishable, as revealed by pulsed-field gel electrophoresis and sequencing of variable regions of the porA gene, but caused strikingly different clinical presentations during 5 months.

  • 33.
    Rytkönen, Anne
    et al.
    KI.
    Albinger, Barbara
    Hansson-Palo, Paola
    Källström, Helena
    Olcén, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology.
    Fredlund, Hans
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology.
    Jonsson, Ann-Beth
    Neisseria meningitidis undergoes PilC phase variation and PilC sequence variation during invasive disease.2004In: Journal of Infectious Diseases, ISSN 0022-1899, E-ISSN 1537-6613, Vol. 189, p. 402-409Article in journal (Refereed)
  • 34.
    Silfverdal, Sven-Arne
    et al.
    Department of Pediatrics, Örebro Medical Centre Hospital, Örebro, Sweden.
    Bodin, L.
    Department of Pediatrics, Örebro Medical Centre Hospital, Örebro, Sweden.
    Hugosson, S.
    Department of Pediatrics, Örebro Medical Centre Hospital, Örebro, Sweden.
    Garpenholt, Örjan
    Department of Pediatrics, Örebro Medical Centre Hospital, Örebro, Sweden.
    Werner, B.
    Department of Pediatrics, Örebro Medical Centre Hospital, Örebro, Sweden.
    Esbjörner, E.
    Department of Pediatrics, Örebro Medical Centre Hospital, Örebro, Sweden.
    Lindquist, B.
    Department of Pediatrics, Örebro Medical Centre Hospital, Örebro, Sweden.
    Olcén, Per
    Department of Pediatrics, Örebro Medical Centre Hospital, Örebro, Sweden.
    Protective effect of breastfeeding on invasive Haemophilus influenzae infection: a case-control study in Swedish preschool children1997In: International Journal of Epidemiology, ISSN 0300-5771, E-ISSN 1464-3685, Vol. 26, no 2, p. 443-450Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: In Orebro County a 2.5-fold increase in the incidence of Haemophilus influenzae (HI) meningitis was found between 1970 and 1980, an observation that initiated the present study.

    MATERIALS AND METHODS: In order to search for associations between morbidity in invasive HI infection and possible risk factors, a case-control study was conducted over a 6-year period from 1987 to 1992, before general Hib vaccination was introduced in Sweden. Fifty-four cases with invasive HI infection 139 matched controls were studied for possible risk factors such as day-care outside the home, short duration of breastfeeding, passive smoking, low socioeconomic level of the household, many siblings in the family, allergy, frequent, infections, repeated antibiotic treatments and immunoglobulin deficiency.

    RESULTS: Multivariate analysis showed a significant association between invasive HI infection and two independent factors, i.e. short duration (< 13 weeks) of exclusive breastfeeding, odds ratio (OR) 3.79 (95% confidence interval [CI] 1.6-8.8) and history of frequent infections, OR 4.49 (95% CI : 1.0-21.0). For the age at onset 12 months or older, the associations were stronger, OR 7.79 (95% CI : 2.4-26.6) and 5.86 (95% CI : 1.1-30.6), respectively. When breastfeeding duration in weeks was analysed as a continuous variable the OR was 0.95 (95% CI : 0.92-0.99), indicating a decreased risk with each additional week. Increased OR were observed for other risk factors as well but not of the magnitude found for short duration of breastfeeding.

    DISCUSSION: The association of decreased risk for invasive HI infection and long duration of breastfeeding was persisting beyond the period of breastfeeding itself. This finding supports the hypothesis of a long-lasting protective effect of breastfeeding on the risk for invasive HI infection. CONCLUSION: A decreased risk for invasive HI infection with long duration of breastfeeding was found. Our results do have implications for strategies in breastfeeding promotion, especially in countries where Hib vaccination is too costly and not yet implemented.

  • 35.
    Silfverdal, Sven-Arne
    et al.
    Department of Paediatrics, Örebro University Hospital, Örebro and Department of Mothers' and Childrens' Health, Östersund Hospital, Östersund.
    Bodin, L.
    Biostatistics and Epidemiology, Örebro University Hospital, Örebro.
    Ulanova, M.
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden; and Division of Medical Sciences, Northern Ontario School of Medicine, Lakehead University, Thunder Bay, Canada.
    Hahn-Zoric, M.
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden.
    Hanson, L. Å.
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden.
    Olcén, Per
    Clinical Microbiology and Immunology, Örebro University Hospital, Örebro.
    Expression of Idiotypic Antibodies-1 and -2 and Breastfeeding in Relation to Antibody Levels Against Haemophilus Influenzae Type b in Children2006In: Scandinavian Journal of Immunology, ISSN 0300-9475, E-ISSN 1365-3083, Vol. 63, no 5, p. 371-375Article in journal (Refereed)
    Abstract [en]

    The aim of the study was to determine the concentrations of serum antibodies against Haemophilus influenzae type b in preschool children in relation to the distribution of idiotypic antibodies 1 and 2 (Id-1 and Id-2) and the exposure to breastfeeding in infancy. Sera were obtained from 74 control children recruited in an earlier case-control study before the introduction of general Hib vaccination. Duration of breastfeeding was monitored, and prevalence of noninvasive infections was registered. Concentrations of IgG1 and IgG2 anti-Hib, as well as of total Id-1 and Id-2, were determined in ELISA. The expression of Id-1 antibodies increased with age in contrast to the Id-2 antibodies that were found only in children up to 24 months of age. Expression of Id-1 antibodies was positively correlated with higher anti-Hib levels of both the IgG1 and IgG2 isotype. Children expressing Id-2 antibodies showed higher IgG2 anti-Hib concentrations than those who did not have Id-2 (P = 0.001). The concentrations of neither Id-1 nor Id-2 antibodies were related to the duration of breastfeeding. Duration of breastfeeding was related to increased anti-Hib IgG2 in healthy children above 18 months of age. These study shows that the expression of idiotype-1 and idiotype-2 antibodies was associated with higher IgG2 anti-Hib concentration and that breastfeeding could enhance the anti-Hib IgG2 production in children.

  • 36.
    Silfverdal, Sven-Arne
    et al.
    Department of Paediatrics, Örebro Medical Center Hospital, Örebro, Sweden.
    Bodin, Lennart
    Department of Occupational and Environmental Medicine, Unit of Biostatistics and Epidemiology, Örebro Medical Center Hospital, Örebro, Sweden.
    Olcén, Per
    Department of Clinical Microbiology, Örebro Medical Center Hospital, Örebro, Sweden.
    Protective effect of breastfeeding: an ecologic study of Haemophilus influenzae meningitis and breastfeeding in a Swedish population1999In: International Journal of Epidemiology, ISSN 0300-5771, E-ISSN 1464-3685, Vol. 28, no 1, p. 152-156Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: In Örebro County, Sweden, a 2.5-fold increase in the incidence of Haemophilus influenzae (HI) meningitis was found between 1970 and 1980. In a case-control study of possible risk factors for invasive HI infection conducted in the same area, 1987-1992, breastfeeding was found to be a strong protective factor.

    MATERIAL AND METHODS: In order to study the relation between incidence rates of HI meningitis between 1956-1992 and breastfeeding rates in the population an ecologic study was performed.

    RESULTS: A strong (negative) correlation between breastfeeding and incidence of HI infection 5 to 10 years later (rho(xy) (s) approximately -0.6) was seen, whereas no relation seems to exist for the time lag 15 years and beyond. The correlation for contemporary data was intermediate. There were similar results for the breastfeeding proportions at 2, 4 as well as 6 months of age.

    DISCUSSION: Our ecologic data are consistent with results from our case-control study. The time-lag for the delayed effect on the population level could be estimated although sparse data make the estimates vulnerable to sampling fluctuations. Limitations with ecologic studies are discussed.

    CONCLUSION: There seems to be an association between high breastfeeding rate in the population and a reduced incidence of HI meningitis 5 to 10 years later. These results do have implications on strategies for breastfeeding promotion, especially in countries where Hib vaccination is too costly and not yet implemented.

  • 37.
    Silfverdal, Sven-Arne
    et al.
    Department of Paediatrics, Örebro Medical Centre Hospital, Örebro.
    Bodin, Lennart
    Department of Biostatistics and Epidemiology, Örebro Medical Centre Hospital, Örebro.
    Ulanova, Marina
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden.
    Hahn-Zoric, Mirjana
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden.
    Hanson, Lars Å.
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden.
    Olcén, Per
    Department of Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro.
    Breastfeeding in relation to non-invasive infections and anti-Hib antibodies in control childrenManuscript (preprint) (Other academic)
    Abstract [en]

    Subjects. Sera were obtained from 74 healthy children, below 6 years of age, recruited as controls in a case control study. Duration and mode of breastfeeding were registered. Frequent infections as stated by parents and levels of antibody to Haemophilus influenzae type b (Hib) were studied in relation to the duration of exclusive breastfeeding.

    Results. Duration of exclusive breastfeeding emerged as a protective factor against frequent non-invasive and non-specific infections in all children with an OR of 0.92 (0.86-0.98), adjusted for passive smoking and sex. After stratification for age the OR decreased to 0.87 (0.76-1.0) in children less than 18 months indicating a stronger protective effect by exclusive breastfeeding against frequent non-invasive infections in younger children compared to older ones. In the younger children sex was the only significant factor associated with the anti-Hib IgG1 and IgG2 antibody levels. Duration of exclusive or any breastfeeding, used either as a dichotomised or a continuous variable, did not show any significant influence on the antibody levels in the younger children. In children ≥ 18 months of age the regression model for anti-Hib IgG2 antibody level was close to significance (p=0.052) but with only a very low R2 around 0.07. When frequent infections or passive smoking was added as an explanatory variable, duration of exclusive breastfeeding became significant (p=0.036) but still with a low R2 Duration of exclusive breastfeeding was significantly related to the anti-Hib IgG2 antibody level in older children without frequent infections. Expression ofldiotype-1 (Id-1) antibodies increased with age in contrast to Id-2 antibodies that were found only in children ≤ 24 months of age, but the levels of neither Id-1 nor Id-2 antibodies were related to duration of breastfeeding or passive smoking. In older children, those without frequent infections showed higher levels of antibodies expression Id-1 than children with frequent infections.

    Discussion. Human milk contains oligosaccharides, leucocytes (granulocytes, macrophages and lymphocytes), hmmones, cytokines, growth factors and other substances that may protect against infection or stimulate the proliferation and the development of the innate and adapted immune system including a stimulatory effect on the anti-Hib antibody response. The distributions of Id-1 and Id-2 were related to age and the IgG2 anti-Hib antibody levels.

    Conclusion. This study shows that exclusive breastfeeding is likely to have a protective effect against frequent non-invasive infections. It also shows that breastfeeding seems to enhance the anti-Hib IgG2 antibody production in healthy children.

  • 38.
    Silfverdal, Sven-Arne
    et al.
    Department of Paediatrics, Örebro Medical Centre Hospital, Örebro.
    Bodin, Lennart
    Department of Biostatistics and Epidemiology, Örebro Medical Centre Hospital, Örebro.
    Ulanova, Marinova
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden.
    Hahn-Zoric, Mirjana
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden.
    Hanson, Lars Å.
    Department of Clinical Immunology, Göteborg University, Göteborg, Sweden.
    Olcén, Per
    Department of Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro.
    Long-term enhancement of the lgG2 antibody response to Haemophilus influenzae type b by breastfeedingManuscript (preprint) (Other academic)
    Abstract [en]

    Subjects. Sets of sera were obtained from 30 children below 6 years of age with invasive Haemophilus influenzae type b (Hib) infection, and therr mothers. DuratiOn and mode of breastfeeding were registered. Levels of IgG1, IgG2, IgA and IgM antibodies agamst Hrb capsular polysaccharide (CP) were determined in sera taken during acute the illness as well as in the early and late convalescence.

    Results. Children 18 months or older with longer duration of exclusive breastfeeding (13 weeks or more, mean 19.3 weeks) had higher anti-Rib antibody levels of the IgG1, IgG2, IgA and IgM isotypes than those with shorter duration of exclusive breastfeeding (less than 13 weeks, mean 5.4 weeks). The difference between the breastfeeding groups was greatest for the IgG2 isotype. In regression analyses the association between the duration of exclusive breastfeeding and the anti-Hib IgG2 level was significant when breastfeeding, type of Hib infection, maternal anti-Rib antibody level and age were used as explanatory factors. In the group of 14 children below 18 months of age no significant differences were noted.

    Discussion. Human milk is rich in IFN-y as well as in IFN-y producing cells, which may result in a specific stimulatory effect of breastfeeding on the IgG2 anti-Rib antibody response. In conclusion, this study indicates the presence of a long lasting enhancing effect of breastfeeding on the antibody response to Hib in children, in particular on IgG2 anti-Hib antibody production.

  • 39.
    Strålin, Kristoffer
    et al.
    Department of Infectious Diseases, Örebro University Hospital, Sweden.
    Bäckman, Anders
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Holmberg, Hans
    Department of Infectious Diseases, Örebro University Hospital, Sweden.
    Fredlund, Hans
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Olcén, Per
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Design of a multiplex PCR for Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae and Chlamydophila pneumoniae to be used on sputum samples2005In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 113, no 2, p. 99-111Article in journal (Refereed)
    Abstract [en]

    A multiplex PCR (mPCR) was developed for simultaneous detection of specific genes for Streptococcus pneumoniae (lytA), Mycoplasma pneumoniae (P1), Chlamydophila pneumoniae (ompA), and Haemophilus influenzae (16S rRNA, with verification PCR for P6). When the protocol was tested on 257 bacterial strains belonging to 37 different species, no false negatives and only one false positive were noted. One Streptococcus mitis out of thirty was positive for lytA. In a pilot application study of 81 sputum samples from different patients with suspected lower respiratory tract infection (LRTI), mPCR identified S. pneumoniae in 25 samples, H. influenzae in 29, M. pneumoniae in 3, and C. pneumoniae in 1. All samples culture positive for S. pneumoniae (n=15) and H. influenzae (n=15) were mPCR positive for the same bacteria. In a pilot control study with nasopharyngeal swabs and aspirates from 10 healthy adults, both culture and mPCR were negative. No PCR inhibition was found in any of the mPCR-negative sputum or nasopharyngeal samples. Whether all samples identified as positive by mPCR are truly positive in an aetiological perspective regarding LRTI remains to be evaluated in a well-defined patient material. In conclusion, the mPCR appears to be a promising tool in the aetiological diagnostics of LRTI.

  • 40.
    Strålin, Kristoffer
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases.
    Fredlund, Hans
    Linköping University, Faculty of Health Sciences. Linköping University, Department of health and environment.
    Olcén, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of health and environment.
    Labsystems enzyme immunoassay for Chlamydia pneumoniae also detects chlamydia psittaci infections.2001In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 39, p. 3425-3426Article in journal (Other (popular science, discussion, etc.))
  • 41.
    Strålin, Kristoffer
    et al.
    Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden.
    Holmberg, Hans
    Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden.
    Olcén, Per
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Antibody response to the patient's own Haemophilus influenzae isolate can support the aetiology in lower respiratory tract infections2004In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 112, no 4-5, p. 299-303Article in journal (Refereed)
    Abstract [en]

    In order to understand the clinical importance of Haemophilus influenzae isolated from sputum samples, an indirect immunofluorescence (IF) assay was developed, using the patient's own isolate as the antigen. The method was tested on samples from six patients with lower respiratory tract infection (LRTI) and H. influenzae isolated from blood (n=2), sputum (n=3) or both (n=1), and on two healthy adults with H. influenzae isolated from the nasopharynx. Between acute and convalescent sera, a four-fold IgG antibody increase was achieved in five of six LRTI patients, including the three blood culture-positive patients. One LRTI patient and the two asymptomatic carriers showed stable antibody levels against their own isolate. Although small, the study indicates that indirect IF can be a promising tool for determining whether a H. influenzae strain represents the probable cause of infection or just a strain colonising the airways. More extensive studies should be performed in order to establish the usefulness of the assay.

  • 42.
    Strålin, Kristoffer
    et al.
    Örebro University Hospital.
    Korsgaard, J
    Aarhus University Hospital.
    Olcén, Per
    Örebro University Hospital.
    Evaluation of a multiplex PCR for bacterial pathogens applied to bronchoalveolar lavage.2006In: European Respiratory Journal, ISSN 0903-1936, E-ISSN 1399-3003, Vol. 28, p. 568-575Article in journal (Refereed)
    Abstract [en]

    The present study assessed the diagnostic usefulness of a multiplex PCR (mPCR) for Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae and Chlamydophila pneumoniae applied to bronchoalveolar lavage (BAL).

    Fibreoptic bronchoscopy was performed on 156 hospitalised adult patients with lower respiratory tract infection (LRTI) and 36 controls. BAL fluid was analysed with bacterial culture and mPCR.

    By conventional diagnostic methods, S. pneumoniae, H. influenzae, M. pneumoniae and C. pneumoniae were aetiological agents in 14, 21, 3.2 and 0% of the LRTI patients, respectively. These pathogens were identified by BAL mPCR in 28, 47, 3.2 and 0.6% of cases, respectively, yielding sensitivities of 86% for S. pneumoniae, 88% for H. influenzae, 100% for M. pneumoniae and 0% for C. pneumoniae, and specificities of 81, 64, 100 and 99% for S. pneumoniae, H. influenzae, M. pneumoniae and C. pneumoniae, respectively. Of the 103 patients who had taken antibiotics prior to bronchoscopy, S. pneumoniae was identified by culture in 2.9% and by mPCR in 31%. Among the controls, mPCR identified S. pneumoniae in 11% and H. influenzae in 39%.

    In lower respiratory tract infection patients, bronchoalveolar lavage multiplex PCR can be useful for identification of Streptococcus pneumoniae, Mycoplasma pneumoniae and Chlamydophila pneumoniae. The method appears to be particularly useful in patients treated with antibiotics.

     

  • 43.
    Strålin, Kristoffer
    et al.
    Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden.
    Korsgaard, Jens
    Department of Chest Diseases, Aarhus University Hospital, Aalborg, Denmark.
    Olcén, Per
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Multiplex PCR fir bacteruak etiology using branchoalveolar lavage in adults with lower respiratory tract infectionManuscript (preprint) (Other academic)
    Abstract [en]

    Study objective: To study the usefulness of a diagnostic multiplex PCR (mPCR) for Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, and Chlamydophila pneumoniae applied to bronchoalveolar lavage (BAL) in lower respiratmy tract infection (LRTI).

    Design: Prospective diagnostic study.

    Setting: Silkeborg County Hospital, Silkeborg, Denmark.

    Patients and participants: Hospitalized adult LRTI patients (n=I56) and adult controls investigated on suspicion of malignancy (n=36).

    Interventions: After fiberoptic bronchoscopy (FOB) BAL fluid was analysed with bacterial culture and mPCR. S. pneumoniae and H. influenzae etiologies were established by cultures from blood, BAL and sputum, and urinary antigen test for S. pneumoniae. M. pneumoniae etiology was established by singleplex PCR on BAL and throat swab, and C. pneumoniae etiology by singleplex PCR and culture on BAL and throat swab.

    Measurements and Results: S. pneumoniae, H. influenzae, M. pneumoniae, and C. pneumoniae were etiologies in 14%, 21%, 3.2%, and 0, of the LRTI patients, respectively. These pathogens were identified by BAL mPCR in 28%, 47%, 3.2%, and 0.6%, respectively. The sensitivities of BAL mPCR were 0.86 for S. pneumoniae, 0.88 for H. influenzae, 1.0 for M. pneumoniae, and 0/0 for C. pneumoniae. The specificities were 0.81 for S. pneumoniae, 0.64 for H. influenzae, 1.0 for M. pneumoniae, and 0.99 for C. pneumoniae. In 103 patients with antibiotics taken prior to FOB, BAL culture and BAL mPCR identified S. pneumoniae in 2.9% and 31%, respectively, and H. influenzae in 20% and 50%, respectively. Among the controls, BAL culture and mPCR identified S. pneumoniae in 8.3% and 11%, respectively, and H. influenzae in 11% and 39%, respectively. No M. pneumoniae or C. pneumoniae was identified among the controls.

    Conclusions: In LRTI patients, BAL mPCR can be useful for identification of S. pneumoniae, M. pneumoniae, and C. pneumoniae. The method appears particularly useful in patients treated with antibiotics.

  • 44.
    Strålin, Kristoffer
    et al.
    Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden.
    Staum Kaltoft, Margit
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden .
    Bossen Konradsen, Helle
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden .
    Olcén, Per
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden .
    Holmberg, Hans
    Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden.
    Comparison of two urinary antigen tests for establishment of pneumococcal etiology of adult community-acquired pneumonia2004In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 42, no 8, p. 3620-3625Article in journal (Refereed)
    Abstract [en]

    The Binax NOW immunochromatographic test (ICT) detecting the pneumococcal C polysaccharide and a serotype-specific latex agglutination (LA) test detecting 23 pneumococcal capsular antigens were evaluated for establishing pneumococcal etiology in community-acquired pneumonia (CAP) by use of nonconcentrated urine. ICT was considered to be strongly positive for result lines at least as intense as the control line and weakly positive for less intense result lines. When 215 adult CAP patients were tested, strong ICT, weak ICT, and LA positivity were found in 28, 24, and 16 patients, respectively; of these patients, 13 (46%), 6 (25%), and 13 (81%), respectively, had pneumococcal bacteremia and 27 (96%), 17 (71%), and 15 (94%), respectively, had Streptococcus pneumoniae isolated from blood, sputum, and/or nasopharynx. Among 108 controls tested, 2 (1.9%) were weakly ICT positive. When weak positivity was considered negative, the sensitivity of ICT decreased from 79% (19 of 24) to 54% (13 of 24), while the specificity increased from 83% (158 of 191) to 92% (176 of 191); no controls were false positive. The sensitivity and specificity of LA were 54% (13 of 24) and 98% (188 of 191), respectively. Eight of nine LA serotypes corresponded to culture serotypes. In conclusion, using nonconcentrated urine and dividing ICT-positive results into strongly and weakly positive results is a suitable way of performing ICT. While weak ICT positivity should be interpreted with caution, strong ICT positivity and LA positivity should be considered supportive of pneumococcal etiology in adult CAP. As such, these assays might have implications for antibiotic use in CAP. LA has promising potential for pneumococcal serotyping, although further evaluation is required.

  • 45.
    Strålin, Kristoffer
    et al.
    Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden.
    Törnqvist, Eva
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Staum Kaltoft, Margit
    Streptococcus Unit, Division of Microbiology and Diagnostics, Statens Serum Institut, Copenhagen, Denmark.
    Olcén, Per
    Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Holmberg, Hans
    Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden.
    Etiologic diagnosis of adult bacterial pneumonia by culture and PCR applied to respiratory tract samples2006In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 44, no 2, p. 643-645Article in journal (Refereed)
    Abstract [en]

    Respiratory culture and multiplex PCR for Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, and Chlamydophila pneumoniae were applied to sputum, nasopharyngeal swabs, and nasopharyngeal aspirates from 235 adult patients with community-acquired pneumonia and 113 controls. Both culture and multiplex PCR performed well with the different samples and appear to be useful as diagnostic tools.

  • 46.
    Taha, Muhamed-Kheir
    et al.
    Neisseria Unit and the French National Reference Center for Meningococci, Institut Pasteur, Paris, France.
    Alonso, Jean-Michel
    Neisseria Unit and the French National Reference Center for Meningococci, Institut Pasteur, Paris, France.
    Cafferkey, Mary
    Irish Meningococcal and Meningitis Reference Laboratory, The Children's University Hospital, Dublin, Ireland.
    Caugant, Dominique A.
    WHO Collaborating Center for Reference and Research on Meningococci, Division of Infectious Disease Control, Norwegian Institute of Public Health and Institute of Oral Biology, University of Oslo, Oslo, Norway.
    Clarke, Stuart C.
    Scottish Meningococcus and Pneumococcus Reference Laboratory, Stobhill Hospital and Division of Infection and Immunity, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow.
    Diggle, Mathew A.
    Scottish Meningococcus and Pneumococcus Reference Laboratory, Stobhill Hospital, Glasgow.
    Fox, Andrew
    Meningococcal Reference Unit, Health Protection Agency, Manchester Royal Infirmary, Manchester, United Kingdom.
    Frosch, Matthias
    Institute for Hygiene and Microbiology, National Reference Center for Meningococci, University of Würzburg, Germany.
    Gray, Stephen J.
    Meningococcal Reference Unit, Health Protection Agency, Manchester Royal Infirmary, Manchester, United Kingdom.
    Guiver, Malcolm
    Meningococcal Reference Unit, Health Protection Agency, Manchester Royal Infirmary, Manchester, United Kingdom.
    Heuberger, Sigrid
    National Reference Centre for Meningococci, Austrian Agency for Health and Food Safety, Graz, Austria.
    Kalmusova, Jitka
    National Reference Laboratory for Meningococcal Infections, National Institute of Public Health, Prague, Czech Republic.
    Kesanopoulos, Konstantinos
    National Meningococcal Reference Laboratory, NIPH, Athens, Greece.
    Klem, Anne-Marie
    WHO Collaborating Center for Reference and Research on Meningococci, Division of Infectious Disease Control, Norwegian Institute of Public Health, Oslo, Norway.
    Kriz, Paula
    National Reference Laboratory for Meningococcal Infections, National Institute of Public Health, Prague, Czech Republic.
    Marsh, John
    Meningococcal Reference Unit, Health Protection Agency, Manchester Royal Infirmary, Manchester, United Kingdom.
    Mölling, Paula
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, University Hospital, Örebro, Sweden.
    Murphy, Karen
    Irish Meningococcal and Meningitis Reference Laboratory, The Children's University Hospital, Dublin, Ireland.
    Olcén, Per
    National Reference Laboratory for Pathogenic Neisseria, Department of Clinical Microbiology, University Hospital, Örebro, Sweden.
    Sanou, Oumar
    Centre Muraz, Bobo Dioulasso, Burkina Faso.
    Tzanakaki, Georgina
    National Meningococcal Reference Laboratory, NIPH, Athens, Greece.
    Vogel, Ulrich
    Institute for Hygiene and Microbiology, National Reference Center for Meningococci, University of Würzburg, Germany.
    Interlaboratory Comparison of PCR-Based Identification and Genogrouping of Neisseria meningitidis2005In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 43, no 1, p. 144-149Article in journal (Refereed)
    Abstract [en]

    Twenty clinical samples (18 cerebrospinal fluid samples and 2 articular fluid samples) were sent to 11 meningococcus reference centers located in 11 different countries. Ten of these laboratories are participating in the EU-MenNet program (a European Union-funded program) and are members of the European Monitoring Group on Meningococci. The remaining laboratory was located in Burkina Faso. Neisseria meningitidis was sought by detecting several meningococcus-specific genes (crgA, ctrA, 16S rRNA, and porA). The PCR-based nonculture method for the detection of N. meningitidis gave similar results between participants with a mean sensitivity and specificity of 89.7 and 92.7%, respectively. Most of the laboratories also performed genogrouping assays (siaD and mynB/sacC). The performance of genogrouping was more variable between laboratories, with a mean sensitivity of 72.7%. Genogroup B gave the best correlation between participants, as all laboratories routinely perform this PCR. The results for genogroups A and W135 were less similar between the eight participating laboratories that performed these PCRs.

  • 47. Taha, Muhamed-Kheir
    et al.
    Olcén, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology.
    Molecular genetic methods in diagnosis and direct characterization of acute bacterial central nervous system infections.2004In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 112, p. 753-770Article in journal (Refereed)
  • 48.
    Thulin, Sara
    et al.
    Örebro University Hospital.
    Olcén, Per
    Örebro University Hospital.
    Fredlund, Hans
    Örebro University Hospital.
    Unemo, Magnus
    Örebro University Hospital.
    Total variation in the penA gene of Neisseria meningitides: Correlation between susceptibility to beta-lactam antibiotics and penA gene heterogeneity.2006In: Antimicrobial Agents and Chemotherapy, ISSN 0066-4804, E-ISSN 1098-6596, Vol. 50, no 10, p. 3317-3324Article in journal (Refereed)
    Abstract [en]

    In recent decades, the prevalence of Neisseria meningitidis isolates with reduced susceptibility to penicillins has increased. The intermediate resistance to penicillin (Peni) for most strains is due mainly to mosaic structures in the penA gene, encoding penicillin-binding protein 2. In this study, susceptibility to ß-lactam antibiotics was determined for 60 Swedish clinical N. meningitidis isolates and 19 reference strains. The penA gene was sequenced and compared to 237 penA sequences from GenBank in order to explore the total identified variation of penA. The divergent mosaic alleles differed by 3% to 24% compared to those of the designated wild-type penA gene. By studying the final 1,143 to 1,149 bp of penA in a sequence alignment, 130 sequence variants were identified. In a 402-bp alignment of the most variable regions, 84 variants were recognized. Good correlation between elevated MICs and the presence of penA mosaic structures was found especially for penicillin G and ampicillin. The Peni isolates comprised an MIC of >0.094 µg/ml for penicillin G and an MIC of >0.064 µg/ml for ampicillin. Ampicillin was the best antibiotic for precise categorization as Pens or Peni. In comparison with the wild-type penA sequence, two specific Peni sites were altered in all except two mosaic penA sequences, which were published in GenBank and no MICs of the corresponding isolates were described. In conclusion, monitoring the relationship between penA sequences and MICs to penicillins is crucial for developing fast and objective methods for susceptibility determination. By studying the penA gene, genotypical determination of susceptibility in culture-negative cases can also be accomplished.

  • 49.
    Unemo, Magnus
    et al.
    National Reference Laboratory for Pathogenic Neisseria, Örebro Medical Centre Hospital, Örebro, Sweden.
    Berglund, Torsten
    Units for Infectious Disease Epidemiology, Microbiology and Tumour Biology Centre, Karolinska Institutet, Stockholm, and Swedish Institute for Infectious Disease Control, Solna, Sweden.
    Olcén, Per
    National Reference Laboratory for Pathogenic Neisseria, Örebro Medical Centre Hospital, Örebro, Sweden.
    Fredlund, Hans
    National Reference Laboratory for Pathogenic Neisseria and Unit for Infectious Disease Control, Department of Clinical Microbiology and Immunology, Örebro Medical Centre Hospital, Örebro, Sweden.
    Pulsed-field gel electrophoresis as an epidemiologic tool for Neisseria gonorrhoeae: Identification of clusters within serovars2002In: Sexually Transmitted Diseases, ISSN 0148-5717, E-ISSN 1537-4521, Vol. 29, no 1, p. 25-31Article in journal (Refereed)
    Abstract [en]

    Background: The increasing incidence of gonorrhea in Sweden in 1998 was due to mostly domestic cases. Among these, two core groups were identified: homosexual men with serovar IB-2 and young heterosexuals with serovar IB-3.

    Goals: To explore the genetic homogeneity/heterogeneity within the predominant serovars, IB-2 and IB-3, of Neisseria gonorrhoeae in Sweden by pulsed-field gel electrophoresis (PFGE) and to compare these results to epidemiologic information, as well as examine the genetic diversity within and between the 25 other represented serovars of N gonorrhoeae.

    Study Design: By PFGE, 237 N gonorrhoeae isolates were examined, and the results were compared with epidemiologic data for the IB-2 and IB-3 isolates.

    Results: In 79% of the domestic IB-2 cases involving homosexuals and 66% of the domestic IB-3 cases involving young heterosexuals, the isolates were genetically indistinguishable by PFGE. A high genetic diversity was identified within and between the 27 included serovars.

    Conclusions: Examination by means of PFGE indicated that one N gonorrhoeae clone each of the serovars IB-2 and IB-3 created the majority of the two core groups of domestic cases.

  • 50.
    Unemo, Magnus
    et al.
    National Reference Laboratory for Pathogenic Neisseria, Örebro Medical Centre Hospital, Örebro, Sweden.
    Olcén, Per
    National Reference Laboratory for Pathogenic Neisseria, Örebro Medical Centre Hospital, Örebro, Sweden.
    Albert, Jan
    Department of Clinical Virology, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden .
    Fredlund, Hans
    National Reference Laboratory for Pathogenic Neisseria and Unit for Infectious Disease Control, Department of Clinical Microbiology, Örebro University Hospital, Örebro.
    Comparison of serologic and genetic porB-based typing of Neisseria gonorrhoeae: consequences for future characterization2003In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 41, no 9, p. 4141-4147Article in journal (Refereed)
    Abstract [en]

    Due to temporal changes in the epidemiology of gonorrhea, a precise characterization of Neisseria gonorrhoeae is essential. In the present study genetic heterogeneity in the porB genes of N. gonorrhoeae was examined, and serovar determination was compared to porB gene sequencing. Among 108 N. gonorrhoeae isolates, phylogenetic analysis of the entire porB alleles (924 to 993 bp) identified 87 unique sequences. By analyzing only the four to six most heterogeneous porB gene regions (174 to 363 bp), 86 out of these 87 genetic variants were identified. Consequently, analysis of shorter highly variable regions of the porB gene generates high-level discriminatory ability as well as fast, objective, reproducible, and portable data for epidemiological characterization of N. gonorrhoeae. Regarding putative antigenic epitopes of PorB for Genetic Systems monoclonal antibodies (MAbs), some of the previous findings were confirmed, but new findings were also observed. For several of the MAbs, however, the precise amino acid residues of PorB critical for single-MAb reactivity were difficult to identify. In addition, repeated serovar determination of 108 N. gonorrhoeae isolates revealed discrepancies for 34 isolates, mostly due to nonreproducible reactivity with single MAbs. Thus, the prospects of a genetic typing system with congruent translation of the serovar determination seem to be limited. In conclusion, analysis of short highly variable regions of the porB gene could form the basis for a fast molecular epidemiological tool for the examination of emergence and transmission of N. gonorrhoeae strains within the community.

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