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  • 1.
    Balkhed Östholm, Åse
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Nilsson, Lennart
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases.
    Hällgren, Anita
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases.
    Duration of travel-associated faecal colonisation with ESBL-producing Enterobacteriaceae - A one year follow-up study2018In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 10Article in journal (Refereed)
    Abstract [en]

    In a previous study, we found that 30% of individuals travelling outside Scandinavia acquired extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) in their faecal flora. The aim of this study was to determine the duration of travel-associated faecal colonisation with ESBL-PE, to assess risk factors for prolonged colonisation and to detect changes in antibiotic susceptibility during prolonged colonisation.

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  • 2.
    Berglund, Björn
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology, Infection and Inflammation. Linköping University, Faculty of Medicine and Health Sciences.
    Bich Hoang, Ngoc Thi
    Vietnam Natl Childrens Hosp, Vietnam.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Kien Le, Ngai
    Vietnam Natl Childrens Hosp, Vietnam.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology, Infection and Inflammation. Linköping University, Faculty of Medicine and Health Sciences.
    Khanh Khu, Dung Thi
    Vietnam Natl Childrens Hosp, Vietnam; TRAC Sweden Vietnam, Vietnam.
    Svartström, Olov
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology.
    Welander, Jenny
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology, Infection and Inflammation. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology, Infection and Inflammation. Linköping University, Faculty of Medicine and Health Sciences.
    Olson, Linus
    TRAC Sweden Vietnam, Vietnam; Karolinska Inst, Sweden.
    Minh Dien, Tran
    Vietnam Natl Childrens Hosp, Vietnam.
    Thanh Le, Hai
    Vietnam Natl Childrens Hosp, Vietnam; TRAC Sweden Vietnam, Vietnam.
    Larsson, Mattias
    TRAC Sweden Vietnam, Vietnam; Karolinska Inst, Sweden.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology, Infection and Inflammation. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases. TRAC Sweden Vietnam, Vietnam.
    Molecular and phenotypic characterization of clinical isolates belonging to a KPC-2-producing strain of ST15 Klebsiella pneumoniae from a Vietnamese pediatric hospital2019In: Antimicrobial Resistance and Infection Control, ISSN 2047-2994, E-ISSN 2047-2994, Vol. 8, no 1, article id 156Article in journal (Refereed)
    Abstract [en]

    Background Carbapenem-resistant Klebsiella pneumoniae are becoming increasingly common in hospital settings worldwide and are a source of increased morbidity, mortality and health care costs. The global epidemiology of carbapenem-resistant K. pneumoniae is characterized by different strains distributed geographically, with the strain ST258 being predominant in Europe and USA, and ST11 being most common in East Asia. ST15 is a less frequently occurring strain but has nevertheless been reported worldwide as a source of hospital outbreaks of carbapenem-resistant K. pneumoniae. Methods In this study, whole-genome sequencing and antimicrobial susceptibility testing was used to characterize 57 clinical isolates of carbapenem-resistant K. pneumoniae belonging to a strain of ST15, which were collected at a Vietnamese pediatric hospital from February throughout September 2015. Results Aside from the carbapenem resistance gene bla(KPC-2), which was carried by all isolates, prevalence of resistance genes to other antibiotics including aminoglycosides, macrolides, quinolones, fosfomycin and trimethoprim, was also high. All isolates were multidrug-resistant. Susceptibility was highest to ceftazidime/avibactam (96%), gentamicin (91%) and tigecycline (82%). Notably, the colistin resistance rate was very high (42%). Single-nucleotide polymorphism analysis indicated that most isolates belonged to a single clone. Conclusions The diverse variety of antibiotic resistance genes and the high antibiotic resistance rates to last-resort antibiotics such as carbapenems and colistin, is indicative of a highly adaptable strain. This emphasizes the importance of implementation of infection controls measures, continued monitoring of antibiotic resistance and prudent use of antibiotics to prevent further selection of resistant strains and the emergence of pan-resistant clones.

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  • 3.
    Berglund, Björn
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Bich Hoang, Ngoc Thi
    Vietnam Natl Childrens Hosp, Vietnam.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Kien Le, Ngai
    Vietnam Natl Childrens Hosp, Vietnam.
    Svartström, Olov
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology.
    Khanh Khu, Dung Thi
    Vietnam Natl Childrens Hosp, Vietnam.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Thanh Le, Hai
    Vietnam Natl Childrens Hosp, Vietnam.
    Welander, Jenny
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology.
    Olson, Linus
    TRAC, Sweden; TRAC, Vietnam; Karolinska Inst, Sweden.
    Larsson, Mattias
    TRAC, Sweden; TRAC, Vietnam; Karolinska Inst, Sweden.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases. TRAC, Sweden; TRAC, Vietnam.
    Insertion sequence transpositions and point mutations in mgrB causing colistin resistance in a clinical strain of carbapenem-resistant Klebsiella pneumoniae from Vietnam2018In: International Journal of Antimicrobial Agents, ISSN 0924-8579, E-ISSN 1872-7913, Vol. 51, no 5, p. 789-793Article in journal (Refereed)
    Abstract [en]

    Resistance among Klebsiella pneumoniae to the last-resort antibiotics carbapenems and colistin is increasing worldwide. In this study, whole-genome sequencing was used to determine the colistin resistance mechanisms in clinical isolates of carbapenem-and colistin-resistant K. pneumoniae from Vietnam. Alterations in the regulatory gene mgrB, via mutations and insertion sequence transpositions, were found in 30 of 31 isolates, emphasising the importance of this resistance mechanism in colistin-resistant K. pneumoniae. (c) 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  • 4.
    Berglund, Björn
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Chen, Baoli
    Shandong Ctr Dis Control and Prevent, Peoples R China.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Sun, Qiang
    Shandong Univ, Peoples R China.
    Xu, Liuchen
    Shandong Ctr Dis Control and Prevent, Peoples R China.
    Welander, Jenny
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology.
    Li, Yan
    Shandong Ctr Dis Control and Prevent, Peoples R China.
    Bi, Zhenwang
    Shandong Ctr Dis Control and Prevent, Peoples R China.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Characterization of extended-spectrum -lactamase-producing Escherichia coli harboring mcr-1 and toxin genes from human fecal samples from China2018In: FUTURE COMPUTING ... the ... International Conference on Future Computational Technologies and Applications, ISSN 1746-0913, E-ISSN 1999-5903, Vol. 13, no 15, p. 1647-1656Article in journal (Refereed)
    Abstract [en]

    Aim: To characterize extended-spectrum -lactamase-producing Escherichia coli harboring the colistin resistance gene mcr-1 from human fecal samples collected in 2012 in a rural area of Shandong province, PR China. Materials amp; methods: Whole-genome sequencing and antimicrobial susceptibility testing was performed on 25 mcr-1-positive isolates to determine carriage of antibiotic resistance and virulence genes, diversity and antibiotic resistance profiles. Results: The isolates were highly genetically diverse and carried a large variety of different antibiotic resistance genes. The multidrug-resistance rate was high (96%). Virulence genes associated with intestinal pathogenic E. coli were carried by 32% of the isolates. Conclusion: Further monitoring of the epidemiological situation is necessary to ensure a preparedness for potential emergence of novel, difficult-to-treat strains and awareness of available treatment options.

  • 5.
    Berglund, Björn
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Hoang, Ngoc Thi Bich
    National Hospital of Pediatrics, Hanoi, Vietnam.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Le, Ngai Kien
    National Hospital of Pediatrics, Hanoi, Vietnam.
    Welander, Jenny
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Khu, Dung Thi Khanh
    National Hospital of Pediatrics, Hanoi, Vietnam.
    Nilsson, Lennart E.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Olson, Linus
    The Karolinska Institute, Stockholm, Sweden.
    Le, Hai Thanh
    National Hospital of Pediatrics, Hanoi, Vietnam.
    Larsson, Mattias
    The Karolinska Institute, Stockholm, Sweden.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases.
    Colistin- and carbapenem-resistant Klebsiella pneumoniae carrying mcr-1 and bla(OXA-48) isolated at a paediatric hospital in Vietnam2018In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 73, no 4, p. 1100-1102Article in journal (Other academic)
    Abstract [en]

    n/a

  • 6.
    Bi, Zhenwang
    et al.
    Shandong Centre Disease Control and Prevent, Peoples R China.
    Berglund, Björn
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Sun, Qiang
    Shandong University, Peoples R China; Shandong University, Peoples R China.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Chen, Baoli
    Shandong Centre Disease Control and Prevent, Peoples R China.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Ding, Lilu
    Shandong University, Peoples R China.
    Stalsby Lundborg, Cecilia
    Karolinska Institute, Sweden.
    Bi, Zhenqiang
    Shandong Centre Disease Control and Prevent, Peoples R China.
    Tomson, Goran
    Karolinska Institute, Sweden.
    Yao, Jingjing
    Shandong University, Peoples R China.
    Gu, Zhanying
    Shandong University, Peoples R China.
    Yin, Xiao
    Jinan Central Hospital, Peoples R China.
    Kou, Zengqiang
    Shandong Centre Disease Control and Prevent, Peoples R China.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Prevalence of the mcr-1 colistin resistance gene in extended-spectrum beta-lactamase-producing Escherichia coli from human faecal samples collected in 2012 in rural villages in Shandong Province, China2017In: International Journal of Antimicrobial Agents, ISSN 0924-8579, E-ISSN 1872-7913, Vol. 49, no 4, p. 493-497Article in journal (Refereed)
    Abstract [en]

    Since its initial discovery in China in 2015, the plasmid-mediated colistin resistance gene mcr-1 has been reported in Escherichia coli isolated from clinical samples, animals and meat worldwide. In this study, 706 extended-spectrum beta-lactamase (ESBL)-producing E. coli from 411 persons were detected in a collection of faecal samples from 1000 rural residents in three counties in Shandong Province, China. These isolates were screened for mcr-1 and phenotypic colistin resistance. The gene was found in 3.5% of the isolates (from 4.9% of persons) from all three counties. All isolates with phenotypic colistin resistance carried mcr-1. These data indicate that commensal carriage of ESBL-producing E. coli with mcr-1 among persons in rural China was already present in 2012 and that mcr-1 was the most important colistin resistance mechanism. Interventions are necessary to minimise further dissemination of mcr-1, which would limit the future usefulness of colistin as a last-resort antibiotic. (C) 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  • 7.
    Chabok, Abbas
    et al.
    Uppsala University.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology . Linköping University, Faculty of Health Sciences.
    Smedh, Kenneth
    Uppsala University.
    Påhlman, Lars
    Uppsala University.
    Nilsson, Lennart
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology . Linköping University, Faculty of Health Sciences.
    Lindberg, Christian
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases . Linköping University, Faculty of Health Sciences.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Medicine, Department of Infectious Diseases in Östergötland.
    Prevalence of fecal carriage of antibiotic-resistant bacteria in patients with acute surgical abdominal infections2010In: SCANDINAVIAN JOURNAL OF GASTROENTEROLOGY, ISSN 0036-5521, Vol. 45, no 10, p. 1203-1210Article in journal (Refereed)
    Abstract [en]

    Objective. Antibiotic resistance is increasing worldwide. The aims of the current study were to determine the fecal carriage of antibiotic-resistant bacteria and antibiotic treatment in surgical patients admitted to hospital due to acute intra-abdominal infections. Materials and methods. Eight Swedish surgical units participated in this prospective multicenter investigation. Rectal swabs were obtained on admission to hospital. Cultures were performed on chromogenic agar and antibiotic susceptibility testing was performed using the disk diffusion method. Extended-spectrum beta-lactamase (ESBL)phenotype was confirmed by Etest. Results. Rectal samples were obtained and analyzed from 208 patients with intra-abdominal surgical infections. Surgery was performed in 134 patients (65%). Cephalosporins were the most frequently used empirical antibiotic therapy. The highest rates of resistance among Enterobacteriaceae were detected for ampicillin (54%), tetracycline (26%), cefuroxime (26%) and trimethoprim-sulfamethoxazole (20%). The prevalence of decreased susceptibility (I + R) for the other antibiotics tested was for ciprofloxacin 20%, piperacillin-tazobactam 17%, cefotaxime 14%, ertapenem 12%, gentamicin 3% and imipenem 0%. ESBL-producing Enterobacteriaceae were found in samples from 10 patients (5%). Three patients had five E. coli isolates producing AmpC enzymes. Conclusions. This study shows a high rate of resistance among Enterobacteriaceae against antibiotics which are commonly used in Sweden and should have implications for the future choice of antibiotics for surgical patients.

  • 8.
    Monstein, Hans-Jurg
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Lennart
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology.
    Molecular identification of blaCTX-M and blaOXY/K1 beta-lactamase genes in Enterobacteriaceae by sequencing of universal M13-sequence tagged PCR-amplicons.2009In: BMC Infectious Diseases, ISSN 1471-2334, E-ISSN 1471-2334, Vol. 9, no 1, p. 7-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Plasmid encoded blaCTX-M enzymes represent an important sub-group of class A beta-lactamases causing the ESBL phenotype which is increasingly found in Enterobacteriaceae including Klebsiella spp. Molecular typing of clinical ESBL-isolates has become more and more important for prevention of the dissemination of ESBL-producers among nosocomial environment.

    METHODS: Multiple displacement amplified DNA derived from 20 K. pneumoniae and 34 K. oxytoca clinical isolates with an ESBL-phenotype was used in a universal CTX-M PCR amplification assay. Identification and differentiation of blaCTX-M and blaOXY/K1 sequences was obtained by DNA sequencing of M13-sequence-tagged CTX-M PCR-amplicons using a M13-specific sequencing primer.

    RESULTS: Nine out of 20 K. pneumoniae clinical isolates had a blaCTX-M genotype. Interestingly, we found that the universal degenerated primers also amplified the chromosomally located K1-gene in all 34 K. oxytoca clinical isolates. Molecular identification and differentiation between blaCTX-M and bla OXY/K1-genes could only been achieved by sequencing of the PCR-amplicons. In silico analysis revealed that the universal degenerated CTX-M primer-pair used here might also amplify the chromosomally located blaOXY and K1-genes in Klebsiella spp. and K1-like genes in other Enterobacteriaceae.

    CONCLUSION: The PCR-based molecular typing method described here enables a rapid and reliable molecular identification of blaCTX-M, and blaOXY/K1-genes. The principles used in this study could also be applied to any situation in which antimicrobial resistance genes would need to be sequenced.

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  • 9.
    Monstein, Hans-Jürg
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Microbiology.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Persis, Shohreh
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Johansson, Anders G
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Microbiology.
    Comparison of a capillary gel electrophoresis-based multiplex PCR assay and ribosomal intergenic transcribed spacer-2 amplicon sequencing for identification of clinically important Candida species2014In: Journal of Microbiological Methods, ISSN 0167-7012, E-ISSN 1872-8359, Vol. 96, p. 81-83Article in journal (Refereed)
    Abstract [en]

    The performance of a commercially available Seegene Seeplex STI Master Panel 3 multiplex PCR for Candida species identification was compared with an internal transcribed spacer 2 (ITS2) PCR assay. We found that the Seeplex assay was specific for identification of C. albicans, C. krusei, C. parapsilosis, C. glabrata, C. tropicalis and C. dubliniensis.

  • 10.
    Saeedi, Baharak
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Gill, Hans
    Linköping University, Department of Biomedical Engineering. Linköping University, The Institute of Technology.
    Hällgren, Anita
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Jonasson, Jon
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Lennart
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Isaksson, Barbro
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Kühn, I.
    Department of Microbiology and Tumour Biology Centre, Karolinska Institute, Stockholm, Sweden.
    Hanberger, Håkan
    Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Phene Plate (PhP) biochemical fingerprinting: a screening method for epidemiological typing of enterococcal isolates?2005In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 113, no 9, p. 603-612Article in journal (Refereed)
    Abstract [en]

    Pulsed-field gel electrophoresis (PFGE) is currently considered the gold standard for genotyping of enterococci. However, PFGE is both expensive and time-consuming. The purpose of this study was to investigate whether the PhP system can be used as a reliable clinical screening method for detection of genetically related isolates of enterococci. If so, it should be possible to minimize the number of isolates subjected to PFGE typing, which would save time and money. Ninety-nine clinical enterococcal isolates were analysed by PhP (similarity levels 0.90–0.975) and PFGE (similarity levels ≤3 and ≤6 bands) and all possible pairs of isolates were cross-classified as matched or mismatched. We found that the probability that a pair of isolates (A and B) belonging to the same type according to PhP also belong to the same cluster according to PFGE, i.e. p(APFGE=BPFGE • APhP=BPhP), and the probability that a pair of isolates of different types according to PhP also belong to different clusters according to PFGE, i.e. p(APFGE≠BPFGE • APhP≠BPhP), was relatively high for E. faecalis (0.86 and 0.96, respectively), but was lower for E. faecium (0.51 and 0.77, respectively). The concordance which shows the probability that PhP and PFGE agree on match or mismatch was 86%–93% for E. faecalis and 54%–66% for E. faecium, which indicates that the PhP method may be useful for epidemiological typing of E. faecalis in the current settings but not for E. faecium.

  • 11.
    Sun, Qiang
    et al.
    Shandong University, Peoples R China.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Zhao, Lingbo
    Shandong University, Peoples R China.
    Stalsby Lundborg, Cecilia
    Karolinska Institute, Sweden.
    Song, Yanyan
    Shandong University, Peoples R China.
    Grape, Malin
    Public Health Agency Sweden, Sweden.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Tomson, Goran
    Karolinska Institute, Sweden; Karolinska Institute, Sweden.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Varying High Levels of Faecal Carriage of Extended-Spectrum Beta-Lactamase Producing Enterobacteriaceae in Rural Villages in Shandong, China: Implications for Global Health2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 11, p. e113121-Article in journal (Refereed)
    Abstract [en]

    Antibiotic resistance is considered a major threat to global health and is affected by many factors, of which antibiotic use is probably one of the more important. Other factors include hygiene, crowding and travel. The rapid resistance spread in Gram-negative bacteria, in particular extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae (ESBL-E), is a global challenge, leading to increased mortality, morbidity and health systems costs worldwide. Knowledge about resistance in commensal flora is limited, including in China. Our aim was to establish the faecal carriage rates of ESBL-E and find its association with known and suspected risk factors in rural residents of all ages in three socio-economically different counties in the Shandong Province, China. Faecal samples and risk-factor information (questionnaire) were collected in 2012. ESBL-E carriage was screened using ChromID ESBL agar. Risk factors were analysed using standard statistical methods. Data from 1000 individuals from three counties and in total 18 villages showed a high and varying level of ESBL-E carriage. Overall, 42% were ESBL-E carriers. At county level the carriage rates were 49%, 45% and 31%, respectively, and when comparing individual villages (n = 18) the rate varied from 22% to 64%. The high level of ESBL-E carriage among rural residents in China is an indication of an exploding global challenge in the years to come as resistance spreads among bacteria and travels around the world with the movement of people and freight. A high carriage rate of ESBL-E increases the risk of infection with multi-resistant bacteria, and thus the need for usage of last resort antibiotics, such as carbapenems and colistin, in the treatment of common infections.

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  • 12. Order onlineBuy this publication >>
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Extended-spectrum beta-lactamase producing Enterobacteriaceae: aspects on detection, epidemiology and multi-drug resistance2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Beta-lactam antibiotics are the largest and most commonly used group of antimicrobial agents in Sweden as well as world-wide. They show very good tolerability and many of the drugs can be administrated orally. Bacteria expressing extended-spectrum beta-lactamases (ESBLs), enzymes hydrolysing penicillins and cephalosporins, may not respond to therapy using some of these antibiotics. The isolates are also often co-resistant to other antimicrobial agents, thus further limiting treatment options. Often parenterally administrated carbapenems is one of few safe treatment options left.

    In this thesis we have investigated the occurrence of ESBL producing Enterobacteriaceae in clinical isolates from Östergötland, Sweden, from 2002 until end of 2007 and the occurrence of multiresistance among ESBL producing E. coli. During these investigations we developed a simple method well suited for high-throughput analysis, for detection and sub typing of common ESBL genes.

    During the six year period, the prevalence of ESBL producing Enterobacteriaceae in Östergötland was very low, <1%, but increasing. The number of patients with ESBL producing E. coli increased significantly from 5 to 47 per year; K. pneumoniae remained between one and four per year. The genes found were dominated by CTX-M group 1 (67%), followed by group 9 (27%). There has been no reason to suspect an outbreak of nosocomial origin. The total consumption of antimicrobial agents was 10.7-12.1 DID per year in primary care; 1.14-1.30 DID per year in hospital care.

    Of eight oral agents tested, only three showed a generally high susceptibility; mecillinam (91%), nitrofurantoin (96%) and fosfomycin (99%). The corresponding figures for the fifteen tested parenterally administrated drugs were; amikacin (96%), tigecycline (99%), colistin (99%) and ≥99% susceptibility for the carbapenems.

    Sixty eight percent of the isolates were multiresistant. The most common multiresistance pattern was ESBL phenotype with decreased susceptibility to trimethoprim, trimethoprimsulfamethoxazole, ciprofloxacin, gentamicin and tobramycin. A significant difference in susceptibility between CTX-M groups, in favor of group 9 over group 1, was seen for many of the antibiotics tested; amoxicillin-clavulanic acid, aztreonam, cafepime, ceftibuten, ceftazidime, ciprofloxacin, gentamicin, piperacillin-tazobactam, temocillin, and tobramycin.

    In conclusion this thesis shows that the prevalence of ESBL producing Enterobacteriaceae in Östergötland was very low but increasing, and the total consumption of antimicrobial agents was stable. A majority of the isolates were multiresistant and a significant difference in susceptibility between CTX-M groups, in favor of group 9 over group 1, was seen for many of the antimicrobial agents tested.

    List of papers
    1. Molecular identification of blaCTX-M and blaOXY/K1 beta-lactamase genes in Enterobacteriaceae by sequencing of universal M13-sequence tagged PCR-amplicons.
    Open this publication in new window or tab >>Molecular identification of blaCTX-M and blaOXY/K1 beta-lactamase genes in Enterobacteriaceae by sequencing of universal M13-sequence tagged PCR-amplicons.
    2009 (English)In: BMC Infectious Diseases, ISSN 1471-2334, E-ISSN 1471-2334, Vol. 9, no 1, p. 7-Article in journal (Refereed) Published
    Abstract [en]

    BACKGROUND: Plasmid encoded blaCTX-M enzymes represent an important sub-group of class A beta-lactamases causing the ESBL phenotype which is increasingly found in Enterobacteriaceae including Klebsiella spp. Molecular typing of clinical ESBL-isolates has become more and more important for prevention of the dissemination of ESBL-producers among nosocomial environment.

    METHODS: Multiple displacement amplified DNA derived from 20 K. pneumoniae and 34 K. oxytoca clinical isolates with an ESBL-phenotype was used in a universal CTX-M PCR amplification assay. Identification and differentiation of blaCTX-M and blaOXY/K1 sequences was obtained by DNA sequencing of M13-sequence-tagged CTX-M PCR-amplicons using a M13-specific sequencing primer.

    RESULTS: Nine out of 20 K. pneumoniae clinical isolates had a blaCTX-M genotype. Interestingly, we found that the universal degenerated primers also amplified the chromosomally located K1-gene in all 34 K. oxytoca clinical isolates. Molecular identification and differentiation between blaCTX-M and bla OXY/K1-genes could only been achieved by sequencing of the PCR-amplicons. In silico analysis revealed that the universal degenerated CTX-M primer-pair used here might also amplify the chromosomally located blaOXY and K1-genes in Klebsiella spp. and K1-like genes in other Enterobacteriaceae.

    CONCLUSION: The PCR-based molecular typing method described here enables a rapid and reliable molecular identification of blaCTX-M, and blaOXY/K1-genes. The principles used in this study could also be applied to any situation in which antimicrobial resistance genes would need to be sequenced.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-17021 (URN)10.1186/1471-2334-9-7 (DOI)19161622 (PubMedID)
    Note
    Original Publication:Hans-Jurg Monstein, Maria Tärnberg and Lennart Nilsson, Molecular identification of blaCTX-M and blaOXY/K1 beta-lactamase genes in Enterobacteriaceae by sequencing of universal M13-sequence tagged PCR-amplicons., 2009, BMC infectious diseases, (9), 1, 7.http://dx.doi.org/10.1186/1471-2334-9-7Copyright: BioMed Centralhttp://www.biomedcentral.com/Available from: 2009-03-03 Created: 2009-03-03 Last updated: 2017-12-13Bibliographically approved
    2. Molecular identification of blaSHV, blaLEN and blaOKP β-lactamase genes in Klebsiella pneumoniae by bi-directional sequencing of universal SP6- and T7-sequence-tagged blaSHV-PCR amplicons
    Open this publication in new window or tab >>Molecular identification of blaSHV, blaLEN and blaOKP β-lactamase genes in Klebsiella pneumoniae by bi-directional sequencing of universal SP6- and T7-sequence-tagged blaSHV-PCR amplicons
    2009 (English)In: Molecular and Cellular Probes, ISSN 1044-7431, E-ISSN 1095-9327, Vol. 23, no 3-4, p. 195-200Article in journal (Refereed) Published
    Abstract [en]

    Plasmid encoded blaSHV enzymes represent an important sub-group of class A β-lactamases causing an ESBL-phenotype which is increasingly found in Enterobacteriaceae including Klebsiella pneumoniae. The chromosomally encoded β-lactamase blaLEN and blaOKP enzymes, which so far only have been found in K. pneumoniae, do not hydrolyse extended-spectrum cephalosporins. In the present study, multiple displacement amplified DNA derived from 20 K. pneumoniae clinical isolates with a blaSHV-like genotype was used in a universal SHV PCR assay using SP6- (forward) and T7- (reverse) sequence-tagged primers. Identification and differentiation of blaSHV, blaLEN and blaOKP genes was obtained by bi-directional amplicon sequencing using SP6- and T7-specific primers. Three well characterised K. pneumoniae strains having a SHV-genotype were included in the study. The bi-directional amplicon sequencing, covering 800 bp (93%) of the blaSHV, blaLEN and blaOKP enzyme encoding sequences, allowed for an unequivocal discrimination of SHV, LEN and OKP genes. Moreover, sequencing revealed the presence of blaSHV allelic variants in six K. pneumoniae isolates in which the amplicons had to be cloned accordingly. Based on deduced amino-acid sequences, a dendrogram was constructed. Seventeen out of 20 K. pneumoniae isolates with an ESBL-phenotype formed a SHV-like cluster, two were LEN-like, and one isolate was OKP-like. The PCR-based molecular typing method described here enables a rapid, reliable and cost-effective identification and differentiation of blaSHV, blaOKP and blaLEN genes.

    Keywords
    Klebsiella pneumoniae; ESBL genes; Concurrent bi-directional SP6- and T7-sequence-tagged; PCR amplicon sequencing
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-17067 (URN)10.1016/j.mcp.2009.01.005 (DOI)
    Note
    Original Publication: Maria Tärnberg, Lennart E. Nilsson and Hans-Jürg Monstein, Molecular identification of blaSHV, blaLEN and blaOKP β-lactamase genes in Klebsiella pneumoniae by bi-directional sequencing of universal SP6- and T7-sequence-tagged blaSHV-PCR amplicons, 2009, Molecular and Cellular Probes, (23), 3-4, 195-200. http://dx.doi.org/10.1016/j.mcp.2009.01.005 Copyright: Elsevier Science B.V., Amsterdam http://www.elsevier.com/ Available from: 2009-06-09 Created: 2009-03-05 Last updated: 2017-12-13Bibliographically approved
    3. Prevalence of extended-spectrum beta-lactamase-producing Enterobacteriaceae and trends in antibiotic consumption in a county of Sweden
    Open this publication in new window or tab >>Prevalence of extended-spectrum beta-lactamase-producing Enterobacteriaceae and trends in antibiotic consumption in a county of Sweden
    Show others...
    2010 (English)In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 42, no 11-12, p. 831-838Article in journal (Refereed) Published
    Abstract [en]

    In the last decade extended-spectrum beta-lactamase (ESBL)-producing bacteria have become an increasing problem. Our aims were to investigate the prevalence of ESBL-producing Enterobacteriaceae and trends in antibiotic use in the county of Ostergotland, Sweden. From 2002 through 2007 there were 224 ESBL-producing Escherichia coli and 23 Klebsiella pneumoniae isolates with an ESBL-phenotype identified among all Enterobacteriaceae isolated at the clinical laboratory. Trends in antibiotic consumption expressed as defined daily doses (DDD) per 1000 inhabitants and day (DID) were studied. The prevalence of ESBL-producing isolates among Enterobacteriaceae in our region is still low (andlt; 1%). Patients with ESBL-producing E. coli increased significantly (p andlt; 0.001) from 5 in y 2002 to 47 in y 2007. CTX-M group 1 was the dominant enzyme group in both E. coli and K. pneumoniae. Antibiotic susceptibility testing of ciprofloxacin, gentamicin and trimethoprim-sulfamethoxazole revealed that 58% of E. coli and 50% of K. pneumoniae isolates were multi-resistant. Antibiotic use remained unchanged from 2001 through 2009, but there was a trend towards increased use of drugs with low ESBL selection potential, which was probably due to the increased prevalence of ESBL producers.

    Place, publisher, year, edition, pages
    Informa Healthcare, 2010
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-63145 (URN)10.3109/00365548.2010.498017 (DOI)000284168300006 ()
    Available from: 2010-12-13 Created: 2010-12-13 Last updated: 2017-12-11Bibliographically approved
    4. In vitro activity of beta-lactam antibiotics against CTX-M-producing Escherichia coli
    Open this publication in new window or tab >>In vitro activity of beta-lactam antibiotics against CTX-M-producing Escherichia coli
    Show others...
    2011 (English)In: European Journal of Clinical Microbiology and Infectious Diseases, ISSN 0934-9723, E-ISSN 1435-4373, Vol. 30, no 8, p. 981-987Article in journal (Refereed) Published
    Abstract [en]

    Beta-lactam antibiotics have been discussed as options for the treatment of infections caused by multiresistant extended-spectrum beta-lactamase (ESBL)-producing bacteria if the minimum inhibitory concentration (MIC) is low. The objective of this study was to investigate the in vitro activity of different beta-lactam antibiotics against CTX-M-producing Escherichia coli. A total of 198 isolates of E. coli with the ESBL phenotype were studied. Polymerase chain reaction (PCR) amplification of CTX-M genes and amplicon sequencing were performed. The MICs for amoxicillin-clavulanic acid, aztreonam, cefepime, cefotaxime, ceftazidime, ceftibuten, ertapenem, imipenem, mecillinam, meropenem, piperacillin-tazobactam, and temocillin were determined with the Etest. Susceptibility was defined according to the breakpoints of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). MIC(50) and MIC(90) values were calculated. Isolates from CTX-M group 9 showed higher susceptibility to the beta-lactam antibiotics tested than isolates belonging to CTX-M group 1. More than 90% of the isolates belonging to CTX-M group 9 were susceptible to amoxicillin-clavulanic acid, ceftazidime, ceftibuten, piperacillin-tazobactam, and temocillin. The susceptibility was high to mecillinam, being 91%, regardless of the CTX-M group. All isolates were susceptible to imipenem and meropenem, and 99% to ertapenem. This study shows significant differences in susceptibility to different beta-lactam antibiotics among the CTX-M-producing E. coli isolates and a significant difference for many antibiotics tested between the CTX-M-producing groups 1 and 9. The good in vitro activity of other beta-lactam antibiotics compared to carbapenems indicate that clinical studies are warranted in order to examine the potential role of these beta-lactam antibiotics in the treatment of infections caused by multiresistant ESBL-producing E. coli.

    Place, publisher, year, edition, pages
    Springer Science Business Media, 2011
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-69787 (URN)10.1007/s10096-011-1183-4 (DOI)000292553500008 ()
    Available from: 2011-08-10 Created: 2011-08-08 Last updated: 2017-12-08Bibliographically approved
    5. In vitro susceptibility of CTX-M-producing Escherichia coli to non-beta-lactam agents
    Open this publication in new window or tab >>In vitro susceptibility of CTX-M-producing Escherichia coli to non-beta-lactam agents
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Background: The objective of this study was to investigate the in vitro activity of different antibiotics against CTX-M-producing Escherichia coli, to determine the occurrence of multiresistance and plasmid mediated quinolone resistance among these isolates.

    Methods: A total of 198 isolates of E. coli with ESBL phenotype and mainly CTX-M genotype, were studied. The MICs for amikacin, chloramphenicol, ciprofloxacin, colistin, fosfomycin, gentamicin, nalidixic acid, nitrofurantoin, tigecycline, tobramycin, trimethoprim and trimethoprim-sulphamethoxazole were determined with the Etest. Susceptibility was defined according to the breakpoints of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). MIC(50) and MIC(90) values were calculated.

    Results: ≥95% of isolates were susceptible to amikacin, nitrofurantoin, colistin, tigecyclin, and fosfomycin. CTX-M group 9 was more susceptible than CTX-M group 1 to ciprofloxacin, gentamicin, and tobramycin. 68% of the isolates were multiresistant, and the most common multi-resistance pattern was ESBL-phenotype with decreased susceptibility to trimethoprim, trimethoprim-sulphamethoxazol, ciprofloxacin, gentamicin and  tobramycin. Only one isolate carried a qnrS1-gene, nine isolates carried aac(6’)-Ib-cr.

    Conclusions: The high frequency of multi-resistance found in this study is alarming and it is urgent to find strategies to limit the emergence and spread of these multi-resistant strains.

    Keywords
    Etest, MIC, ESBL
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-76133 (URN)
    Available from: 2012-03-28 Created: 2012-03-28 Last updated: 2012-03-28Bibliographically approved
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    Extended-spectrum beta-lactamase producing Enterobacteriaceae: aspects on detection, epidemiology and multi-drug resistance
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  • 13.
    Tärnberg, Maria
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Jakobsson, Tell
    Linköping University, Department of Clinical and Experimental Medicine, Obstetrics and gynecology. Linköping University, Faculty of Health Sciences.
    Jonasson, Jon
    Linköping University, Department of Clinical and Experimental Medicine, Molecular and Immunological Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Forsum, Urban
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Identification of randomly selected colonies of Lactobacilli from normal vaginal fluid by pyrosequencing of the 16S rDNA Variable V1 and V3 Regions2002In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 110, no 11, p. 802-810Article in journal (Refereed)
    Abstract [en]

    The present study aimed to characterize lactobacilli in vaginal fluid from 23 adult healthy women by using high-throughput DNA sequencing for identification of a large number of randomly selected colonies appearing on Rogosa and blood agar. The typing method was based on broad-range PCR of 16S rRNA gene variable regions V1 and V3, pyrosequencing, and classification of the fragments by alignment with NCBI-catalogued sequences and type strain sequences. Four major groups of sequences were found among the 402 isolates clearly corresponding to Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners and Lactobacillus jensenii when compared to the sequences obtained for type strains. Our results indicate that pyrosequencing of 16S rRNA gene fragments as used here is a fast and reliable method well suited for identification to the species level, even within the Lactobacillus acidophilus complex.

  • 14.
    Tärnberg, Maria
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Dowzicky, Michael J.
    Pfizer Inc, PA 19426 USA.
    Antimicrobial activity against a global collection of skin and skin structure pathogens: results from the Tigecycline Evaluation and Surveillance Trial (TEST), 2010-20142016In: International Journal of Infectious Diseases, ISSN 1201-9712, E-ISSN 1878-3511, Vol. 49, p. 141-148Article in journal (Refereed)
    Abstract [en]

    Background: As part of the Tigecycline Evaluation and Surveillance Trial (T.E.S.T.) we report antimicrobial resistance among Gram-positive and Gram-negative isolates collected globally from integumentary sources between 2010 and 2014. Methods: Minimum inhibitory concentrations and antimicrobial resistance were determined according to Clinical and Laboratory Standards Institute guidelines (US Food and Drug Administration breakpoints against tigecycline). The Cochran-Armitage trend test was used to identify statistically significant changes in resistance. Results: Global rates of methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Acinetobacter baumannii were 38% and 43%, respectively. No S. aureus isolates were resistant to linezolid or vancomycin; all isolates were susceptible to tigecycline. Two percent of Enterococcus faecalis and 28% of Enterococcus faecium were vancomycin-resistant. Extended-spectrum beta-lactamase (ESBL) producers accounted for 22% of Klebsiella pneumoniae and 16% of Escherichia coli. Resistance to minocycline among E. faecalis, E. faecium, K. pneumoniae, and E. coli decreased significantly (p amp;lt; 0.0001). There were significant increases (p amp;lt; 0.0001) in A. baumannii resistance to cefepime, ceftazidime, ceftriaxone, levofloxacin, meropenem, and piperacillin-tazobactam. Conclusions: Among isolates from integumentary sources, rates of MRSA and ESBL-producing Enterobacteriaceae are stabilizing. Carbapenems and tigecycline have retained their in vitro activity against Gram-positive and Gram-negative organisms. Few agents were active against A. baumannii; its increasing resistance is cause for concern. (C) 2016 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.

  • 15.
    Tärnberg, Maria
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Lennart E.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology.
    Monstein, Hans-Jürg
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Molecular identification of blaSHV, blaLEN and blaOKP β-lactamase genes in Klebsiella pneumoniae by bi-directional sequencing of universal SP6- and T7-sequence-tagged blaSHV-PCR amplicons2009In: Molecular and Cellular Probes, ISSN 1044-7431, E-ISSN 1095-9327, Vol. 23, no 3-4, p. 195-200Article in journal (Refereed)
    Abstract [en]

    Plasmid encoded blaSHV enzymes represent an important sub-group of class A β-lactamases causing an ESBL-phenotype which is increasingly found in Enterobacteriaceae including Klebsiella pneumoniae. The chromosomally encoded β-lactamase blaLEN and blaOKP enzymes, which so far only have been found in K. pneumoniae, do not hydrolyse extended-spectrum cephalosporins. In the present study, multiple displacement amplified DNA derived from 20 K. pneumoniae clinical isolates with a blaSHV-like genotype was used in a universal SHV PCR assay using SP6- (forward) and T7- (reverse) sequence-tagged primers. Identification and differentiation of blaSHV, blaLEN and blaOKP genes was obtained by bi-directional amplicon sequencing using SP6- and T7-specific primers. Three well characterised K. pneumoniae strains having a SHV-genotype were included in the study. The bi-directional amplicon sequencing, covering 800 bp (93%) of the blaSHV, blaLEN and blaOKP enzyme encoding sequences, allowed for an unequivocal discrimination of SHV, LEN and OKP genes. Moreover, sequencing revealed the presence of blaSHV allelic variants in six K. pneumoniae isolates in which the amplicons had to be cloned accordingly. Based on deduced amino-acid sequences, a dendrogram was constructed. Seventeen out of 20 K. pneumoniae isolates with an ESBL-phenotype formed a SHV-like cluster, two were LEN-like, and one isolate was OKP-like. The PCR-based molecular typing method described here enables a rapid, reliable and cost-effective identification and differentiation of blaSHV, blaOKP and blaLEN genes.

    Download full text (pdf)
    FULLTEXT02
  • 16.
    Tärnberg, Maria
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Östholm Balkhed, Åse
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Microbiology. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Infectious Diseases in Östergötland.
    Monstein, Hans-Jurg
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Microbiology.
    Hällgren, Anita
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Infectious Diseases in Östergötland.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Infectious Diseases in Östergötland.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    In vitro activity of beta-lactam antibiotics against CTX-M-producing Escherichia coli2011In: European Journal of Clinical Microbiology and Infectious Diseases, ISSN 0934-9723, E-ISSN 1435-4373, Vol. 30, no 8, p. 981-987Article in journal (Refereed)
    Abstract [en]

    Beta-lactam antibiotics have been discussed as options for the treatment of infections caused by multiresistant extended-spectrum beta-lactamase (ESBL)-producing bacteria if the minimum inhibitory concentration (MIC) is low. The objective of this study was to investigate the in vitro activity of different beta-lactam antibiotics against CTX-M-producing Escherichia coli. A total of 198 isolates of E. coli with the ESBL phenotype were studied. Polymerase chain reaction (PCR) amplification of CTX-M genes and amplicon sequencing were performed. The MICs for amoxicillin-clavulanic acid, aztreonam, cefepime, cefotaxime, ceftazidime, ceftibuten, ertapenem, imipenem, mecillinam, meropenem, piperacillin-tazobactam, and temocillin were determined with the Etest. Susceptibility was defined according to the breakpoints of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). MIC(50) and MIC(90) values were calculated. Isolates from CTX-M group 9 showed higher susceptibility to the beta-lactam antibiotics tested than isolates belonging to CTX-M group 1. More than 90% of the isolates belonging to CTX-M group 9 were susceptible to amoxicillin-clavulanic acid, ceftazidime, ceftibuten, piperacillin-tazobactam, and temocillin. The susceptibility was high to mecillinam, being 91%, regardless of the CTX-M group. All isolates were susceptible to imipenem and meropenem, and 99% to ertapenem. This study shows significant differences in susceptibility to different beta-lactam antibiotics among the CTX-M-producing E. coli isolates and a significant difference for many antibiotics tested between the CTX-M-producing groups 1 and 9. The good in vitro activity of other beta-lactam antibiotics compared to carbapenems indicate that clinical studies are warranted in order to examine the potential role of these beta-lactam antibiotics in the treatment of infections caused by multiresistant ESBL-producing E. coli.

  • 17.
    Woksepp, Hanna
    et al.
    Kalmar County Hospital.
    Jernberg, Cecilia
    Swedish Institute for Communicable Disease Control, Solna.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Ryberg, Anna
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Microbiology.
    Brolund, Alma
    Swedish Institute for Communicable Disease Control, Solna.
    Nordvall, Michaela
    Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Microbiology.
    Olsson-Liljequist, Barbro
    Swedish Institute for Communicable Disease Control, Solna.
    Tegmark Wisell, Karin
    Swedish Institute for Communicable Disease Control, Solna.
    Monstein, Hans-Jurg
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Microbiology.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Schön, Thomas
    Kalmar County Hospital.
    High-Resolution Melting-Curve Analysis of Ligation-Mediated Real-Time PCR for Rapid Evaluation of an Epidemiological Outbreak of Extended-Spectrum-Beta-Lactamase-Producing Escherichia coli2011In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 49, no 12, p. 4032-4039Article in journal (Refereed)
    Abstract [en]

    Methods for the confirmation of nosocomial outbreaks of bacterial pathogens are complex, expensive, and time-consuming. Recently, a method based on ligation-mediated PCR (LM/PCR) using a low denaturation temperature which produces specific melting-profile patterns of DNA products has been described. Our objective was to further develop this method for real-time PCR and high-resolution melting analysis (HRM) in a single-tube system optimized in order to achieve results within 1 day. Following the optimization of LM/PCR for real-time PCR and HRM (LM/HRM), the method was applied for a nosocomial outbreak of extended-spectrum-beta-lactamase (ESBL)-producing and ST131-associated Escherichia coli isolates (n = 15) and control isolates (n = 29), including four previous clusters. The results from LM/HRM were compared to results from pulsed-field gel electrophoresis (PFGE), which served as the gold standard. All isolates from the nosocomial outbreak clustered by LM/HRM, which was confirmed by gel electrophoresis of the LM/PCR products and PFGE. Control isolates that clustered by LM/PCR (n = 4) but not by PFGE were resolved by confirmatory gel electrophoresis. We conclude that LM/HRM is a rapid method for the detection of nosocomial outbreaks of bacterial infections caused by ESBL-producing E. coli strains. It allows the analysis of isolates in a single-tube system within a day, and the discriminatory power is comparable to that of PFGE.

    Download full text (pdf)
    fulltext
  • 18.
    Östholm Balkhed, Åse
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Microbiology.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Monstein, Hans-Jurg
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Microbiology.
    Hällgren, Anita
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Infectious Diseases in Östergötland.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Infectious Diseases in Östergötland.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    In vitro susceptibility of CTX-M-producing Escherichia coli to non-beta-lactam agentsManuscript (preprint) (Other academic)
    Abstract [en]

    Background: The objective of this study was to investigate the in vitro activity of different antibiotics against CTX-M-producing Escherichia coli, to determine the occurrence of multiresistance and plasmid mediated quinolone resistance among these isolates.

    Methods: A total of 198 isolates of E. coli with ESBL phenotype and mainly CTX-M genotype, were studied. The MICs for amikacin, chloramphenicol, ciprofloxacin, colistin, fosfomycin, gentamicin, nalidixic acid, nitrofurantoin, tigecycline, tobramycin, trimethoprim and trimethoprim-sulphamethoxazole were determined with the Etest. Susceptibility was defined according to the breakpoints of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). MIC(50) and MIC(90) values were calculated.

    Results: ≥95% of isolates were susceptible to amikacin, nitrofurantoin, colistin, tigecyclin, and fosfomycin. CTX-M group 9 was more susceptible than CTX-M group 1 to ciprofloxacin, gentamicin, and tobramycin. 68% of the isolates were multiresistant, and the most common multi-resistance pattern was ESBL-phenotype with decreased susceptibility to trimethoprim, trimethoprim-sulphamethoxazol, ciprofloxacin, gentamicin and  tobramycin. Only one isolate carried a qnrS1-gene, nine isolates carried aac(6’)-Ib-cr.

    Conclusions: The high frequency of multi-resistance found in this study is alarming and it is urgent to find strategies to limit the emergence and spread of these multi-resistant strains.

  • 19.
    Östholm Balkhed, Åse
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Infectious Diseases in Östergötland.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Monstein, Hans-Jürg
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Hällgren, Anita
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Infectious Diseases in Östergötland.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Infectious Diseases in Östergötland.
    Nilsson, Lennart E.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    High frequency of co-resistance in CTX-M-producing Escherichia coli to non-beta-lactam antibiotics, with the exception of amikacin, nitrofurantoin, colistin, tigecycline, and fosfomycin, in a county of Sweden2013In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 45, no 4, p. 271-278Article in journal (Refereed)
    Abstract [en]

    Background: The objective of this study was to investigate the in vitro activity of different antibiotics against CTX-M-producing Escherichia coli in a county of Sweden, and to determine the occurrence of multi-resistance and plasmid- mediated quinolone resistance among these isolates. Methods: A total of 198 isolates of E. coli with extended-spectrum beta-lactamase (ESBL) phenotype and mainly CTX-M genotype were studied. The minimum inhibitory concentrations (MICs) for amikacin, chloramphenicol, ciprofloxacin, colistin, fosfomycin, gentamicin, nalidixic acid, nitrofurantoin, tigecycline, tobramycin, trimethoprim, and trimethoprim-sulfamethoxazole were determined with the Etest. Susceptibility was defined according to the breakpoints of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). MIC(50) and MIC(90) values were calculated. Results: Ninety-five percent or more of the isolates were susceptible to amikacin, nitrofurantoin, colistin, tigecycline, and fosfomycin. CTX-M group 9 was more susceptible than CTX-M group 1 to ciprofloxacin, gentamicin, and tobramycin. Sixty-eight percent of the isolates were multi-resistant, and the most common multi-resistance pattern was ESBL phenotype with decreased susceptibility to trimethoprim, trimethoprim-sulfamethoxazole, ciprofloxacin, gentamicin, and tobramycin. Only 1 isolate carried a qnrS1 gene, but 37% carried aac(6')-Ib-cr. Conclusions: A high frequency of co-resistance between ESBL-producing E. coli and non-beta-lactam antibiotics was seen. On the other hand, very high susceptibility was seen for amikacin, nitrofurantoin, colistin, tigecycline, and fosfomycin. These data support the replacement of gentamicin and tobramycin, normally used in Sweden, with amikacin, for severe infections.

  • 20.
    Östholm Balkhed, Åse
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Infectious Diseases in Östergötland.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Johansson, Anita
    Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Microbiology.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Medicine, Department of Infectious Diseases in Östergötland.
    Monstein, Hans-Jurg
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Molecular Biological Techniques.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Prevalence of extended-spectrum beta-lactamase-producing Enterobacteriaceae and trends in antibiotic consumption in a county of Sweden2010In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 42, no 11-12, p. 831-838Article in journal (Refereed)
    Abstract [en]

    In the last decade extended-spectrum beta-lactamase (ESBL)-producing bacteria have become an increasing problem. Our aims were to investigate the prevalence of ESBL-producing Enterobacteriaceae and trends in antibiotic use in the county of Ostergotland, Sweden. From 2002 through 2007 there were 224 ESBL-producing Escherichia coli and 23 Klebsiella pneumoniae isolates with an ESBL-phenotype identified among all Enterobacteriaceae isolated at the clinical laboratory. Trends in antibiotic consumption expressed as defined daily doses (DDD) per 1000 inhabitants and day (DID) were studied. The prevalence of ESBL-producing isolates among Enterobacteriaceae in our region is still low (andlt; 1%). Patients with ESBL-producing E. coli increased significantly (p andlt; 0.001) from 5 in y 2002 to 47 in y 2007. CTX-M group 1 was the dominant enzyme group in both E. coli and K. pneumoniae. Antibiotic susceptibility testing of ciprofloxacin, gentamicin and trimethoprim-sulfamethoxazole revealed that 58% of E. coli and 50% of K. pneumoniae isolates were multi-resistant. Antibiotic use remained unchanged from 2001 through 2009, but there was a trend towards increased use of drugs with low ESBL selection potential, which was probably due to the increased prevalence of ESBL producers.

  • 21.
    Östholm Balkhed, Åse
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Infectious Diseases.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Lennart E.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Infectious Diseases.
    Hällgren, Anita
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Infectious Diseases.
    Travel-associated faecal colonization with ESBL-producing Enterobacteriaceae: incidence and risk factors2013In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 68, no 9, p. 2144-2153Article in journal (Refereed)
    Abstract [en]

    Objectives To study the acquisition of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) among the faecal flora during travel, with a focus on risk factors, antibiotic susceptibility and ESBL-encoding genes.

    Methods An observational prospective multicentre cohort study of individuals attending vaccination clinics in south-east Sweden was performed, in which the submission of faecal samples and questionnaires before and after travelling outside Scandinavia was requested. Faecal samples were screened for ESBL-PE by culturing on ChromID ESBL and an in-house method. ESBL-PE was confirmed by phenotypic and genotypic methods. Susceptibility testing was performed with the Etest. Individuals who acquired ESBL-PE during travel (travel-associated carriers) were compared with non-carriers regarding risk factors, and unadjusted and adjusted ORs after manual stepwise elimination were calculated using logistic regression.

    Results Of 262 enrolled individuals, 2.4% were colonized before travel. Among 226 evaluable participants, ESBL-PE was detected in the post-travel samples from 68 (30%) travellers. The most important risk factor in the final model was the geographic area visited: Indian subcontinent (OR 24.8, P < 0.001), Asia (OR 8.63, P < 0.001) and Africa north of the equator (OR 4.94, P  = 0.002). Age and gastrointestinal symptoms also affected the risk significantly. Multiresistance was seen in 77 (66%) of the ESBL-PE isolates, predominantly a combination of reduced susceptibility to third-generation cephalosporins, trimethoprim/sulfamethoxazole and aminoglycosides. The most common species and ESBL-encoding gene were Escherichia coli (90%) and CTX-M (73%), respectively.

    Conclusion Acquisition of multiresistant ESBL-PE among the faecal flora during international travel is common. The geographical area visited has the highest impact on ESBL-PE acquisition.

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