Coagulase-negative staphylococci (CNS) are the leading cause of late-onset sepsis in newborns (>72 h of age). Our aim was to determine whether phenotypic and/or genotypic differences existed between blood isolates of CNS regarded as inducers of sepsis or as contaminants. Ninety-seven bloodisolates of CNS recovered from newborns at the neonatal intensive care unit, Örebro, Sweden in 1983–1997 were analysed. Twenty-nine of them (30%) were classified as sepsis isolates and 68 (70%) as contaminants. The most prevalent species was Staphylococcus epidermidis (n=59). Staphylococcus haemolyticus (n=16) was most often isolated from newborns with the lowest gestational age and birth weight. Biochemical typing using the Phene Plate system (PhP) and genotyping using pulsed-field gel electrophoresis (PFGE) showed that the S. epidermidis isolates regarded as inducers of sepsis (n=16) were more homogeneous than isolates considered contaminants (n=37). One main genotypic group, representing seven (44%) isolates, was identified among the sepsis isolates. Phenotypically the S. epidermidis sepsis isolates comprised three major clusters. In contrast, among the S. epidermidis contaminants, eight genotypic groups and two phenotypic clusters were identified. The dominating genotypic group among the sepsis isolates of S. epidermidis may represent strains with higher invasive capacity.
Conventional methods for identification of nontuberculous mycobacteria (NTM) are often inexact and time consuming. Sequencing of bacterial 16S rDNA is accurate, rapid and effective. We have retrospectively evaluated the discriminative power of pyrosequencing of a short hypervariable 16S rDNA fragment as a simple and rapid tool for NTM characterization. A series of 312 clinical NTM isolates, excluding the M. avium/intracellulare complex, was investigated. When species could not be resolved by sequencing alone, growth rate and pigment production were also examined. 54% (170/312) of the isolates were unambiguously identified by both methods. An additional 14% (45/312) were directly identified to species by conventional 16S rDNA sequencing but needed complementary phenotypic analysis when examined by pyrosequencing. The remaining 31% (97/312) needed additional phenotypic analysis for both sequencing methods. We consider the pyrosequencing procedure to be a useful alternative for the identification of several NTM species, and a versatile tool for the characterization of clinical NTM isolates. At times it requires additional tests for definite species diagnosis and correct identification. Copyright © Apmis 2007.
We used ELISPOT and cell ELISA to study secretion of IL-4, IFN-γ, TGF-β, IL-6, and TNF-α by circulating mononuclear cells during the course of Guillain-Barré syndrome (GBS). Compared to healthy controls, patients with GBS had higher numbers of TGF-β-secreting cells and the number of individuals with myelin-peptide-induced IL-4 and TGF-β secretion was higher in the GBS group. No significant differences were seen concerning the predominantly pro-inflammatory cytokines IFN-γ, IL-6 or TNF-α. Our findings indicate a down-regulatory role for TGF-β and IL-4 in GBS.
The DNA repair genes XRCC1 and XRCC6 have been proposed to participate in the pathological process of cancer by modulating the DNA repair capacity. This study evaluated the susceptibility of the single-nucleotide polymorphisms (SNPs) XRCC1 (rs25487, G amp;gt; A) and XRCC6 (rs2267437, C amp;gt; G) to colorectal cancer (CRC) and their association with clinical parameters in Swedish patients with CRC. Using the TaqMan system, these SNPs were screened in 452 patients and 464 controls. No significant difference in genotype distribution was found between the patients and controls, or any significant association with cancer-specific or disease-free survival in patients. However, we showed that the carriers of allele A in XRCC1 (rs25487, G amp;gt; A) were connected with a higher risk of disseminated CRC (Odds Ratio = 1.64; 95% Confidence Interval = 1.12-2.41, p = 0.012).
Five commercial Borrelia serology kits available in Sweden were evaluated and compared for their diagnostic performance in sera from clinically well-characterized patient groups. With the clinically defined groups as the gold standard, i.e. without knowledge of antibody status in serum and cerebrospinal fluid, the diagnostic performance of the kits was compared and important differences in diagnostic usefulness were found. The kits from Abbot and DAKO, that often predict clinically relevant Borrelia infection and do not detect antibodies in sera from patients without strong suspicion of Borrelia infection, were considered the most useful in the population studied. This kind of validation study is an important part of good laboratory practice and should be performed by laboratories serving patient populations with varying endemicity of Borrelia.
Clostridioides difficile infections (CDIs) in Sweden are mostly hospital-associated (HA) with limited knowledge regarding community-associated (CA) infections. Here, we investigated the molecular epidemiology of clinical isolates of CA-CDI and HA-CDI in a Swedish county. Data and isolates (n = 156) of CDI patients (n = 122) from Jonkoping county, October 2017-March 2018, were collected and classified as CA (without previous hospital care or onset <= 2 days after admission or >12 weeks after discharge from hospital) or HA (onset >3 days after hospital admission or within 4 weeks after discharge). Molecular characterization of isolates included PCR ribotyping (n = 156 isolates) and whole genome sequencing with single nucleotide polymorphisms (SNP) analysis (n = 53 isolates). We classified 47 patients (39%) as CA-CDI and 75 (61%) as HA-CDI. Between CA-CDI and HA-CDI patients, we observed no statistically significant differences regarding gender, age, 30-day mortality or recurrence. Ribotype 005 (RR 3.1; 95% CI: 1.79-5.24) and 020 (RR 2.5; 95% CI: 1.31-4.63) were significantly associated with CA-CDI. SNP analysis identified seven clusters (0-2 SNP difference) involving 17/53 isolates of both CA-CDI and HA-CDI. Molecular epidemiology differed between CA-CDI and HA-CDI and WGS analysis suggests transmission of CDI within and between hospitals and communities.
Papanicolaou-stained cervicovaginal smears (Pap smears) are used to screen for cervical cancer. Since there is a lack of consensus in published reports respecting the efficacy of Pap-stained smears in BV diagnostics, there is a need to validate their use for diagnosis of BV. Slides from the international BV00 workshop were Pap stained and independently analyzed by four investigators under a phase-contrast microscope. All workshop slides - whether Pap-stained, Gram-stained or rehydrated air-dried smears - were scored according to the same Nugent classification. The diagnostic accuracy of Pap smears for diagnosis of BV had a sensitivity of 0.85 and a specificity of 0.92, with a positive and negative predictive value of 0.84 and 0.93, respectively. The interobserver weighted kappa index was 0.86 for Pap-stained smears compared to 0.81 for Gram-stained smears, and 0.70 for rehydrated air-dried smears using the mean Nugent score as the criterion standard. Provided that the samples are taken from equivalent locations (the vaginal fornix) and analyzed according to the same scoring criteria, there is no discernable difference in the diagnostic accuracy of the three smear-staining methods. The Pap-stained vaginal smears can be used as a wholly adequate alternative to Gram-stained smears for BV diagnosis. © Apmis 2007.
The aim of the present study was to develop a PCR-based method to detect and identify fungi directly from human venous blood. We used broad-range PCR primers that targeted a part of the large subunit 28S rRNA genes. To obtain species-specific hybridisation probes, type strains of Candida albicans, C. glabrata, C. krusei, C. parapsilosis, C. tropicalis and Cryptococcus neoformans were PCR amplified, and the amplicons were analysed by gene sequencing. Based on the sequence analysis, species-specific probes that targeted variable regions were designed and used in hybridisation analyses. Between 2 to 10 fungal cells/ml of spiked blood samples could be detected and correctly identified to species. We applied the technique to blood samples obtained from two patients with or two patients without verified candidaemia. The three samples of candidaemia patients were correctly identified to species level, and those of the negative patients remained negative. This method is a potential tool for diagnosis of systemic invasive candidiasis.
Diagnosing bacterial vaginosis (BV) has long been based on the clinical criteria of Amsel et al., whereby three of four defined criteria must be satisfied. Though there are other criteria and scoring methods which function well in comparison (i.e. Nugent scoring), it is not certain that they will always identify the same category of patients. Point-of-care methods based on various combinations of microbial products, presence of RNA, or more complex laboratory instrumentations such as sensor arrays, have also been introduced for the diagnosis of BV No method for diagnosing BV can at present be regarded as the best. It could be that - based partly on tacit knowledge on the part of the clinical investigators scoring in the clinic - various scoring systems have been chosen to fit a particular BV-related problem in a particular population. In this review we critically examine these pertinent issues influencing clinical scoring and laboratory diagnostics of BV. Copyright © APMIS 2005.
The development of bacterial vaginosis (BV) among women of childbearing age and the resulting quantitative and qualitative shift from normally occurring lactobacilli in the vagina to a mixture of mainly anaerobic bacteria is a microbiological and immunological enigma that so far has precluded the formulation of a unifying generally accepted theory on the aetiology and clinical course of BV. This critical review highlights some of the more important aspects of BV research that could help in formulating new basic ideas respecting the biology of BV, not least the importance of the interleukin mediators of local inflammatory responses and the bacterial shift from the normally occurring lactobacilli species: L. crispatus, L. gasseri, L. jensenii, and L. iners to a mixed flora dominated by anaerobic bacteria. Copyright © APMIS 2005.
The objective of this study was to investigate a sudden increase in methicillin-resistant Staphylococcus aureus (MRSA) cases primarily in one maternity ward at the Center for Childrens and Womens Health at Linkoping University Hospital, Sweden. Approximately 300 individuals including patients, their family members, and healthcare workers were screened for MRSA. The antibiotic susceptibility was tested and isolates polymerase chain reaction (PCR)-positive for the mecA gene were spa typed. Isolates with the same antibiogram and spa type were further whole genome sequenced. Compliance to current cleaning and hygiene routines was also controlled, and environmental samples collected. The results showed that a total of 13 individuals were involved in the outbreak. It was caused by a t386 MRSA strain (ST-1, NCBI-accession AB505628) with additional resistance to erythromycin and clindamycin. All cases were epidemiologically connected to the index patient, who had recently emigrated from a high-endemic area for MRSA. With improved cleaning and better compliance to basic hygiene routines, no further cases were reported. This study demonstrates how rapid an MRSA strain can disseminate in a ward with susceptible patients and insufficient cleaning and hygiene. For a better control of MRSA, clinical cultures and screening samples need to be obtained early and more extensively than according to the current recommendations.
This study aimed to determine the effects of advanced glycation end products (AGEs) on endothelial cytoskeleton morphology and permeability, and to detect the underlying signaling mechanisms involved in these responses. Cultured endothelial cells (ECs) were exposed to AGE-modified human serum albumin (AGE-HSA), and EC cytoskeletal changes were evaluated by observing fluorescence of F-actin following ligation with labeled antibodies. Endothelial permeability was detected by measuring the flux of TRITC-albumin across the EC monolayers. To explore the signaling pathways behind AGE-induced EC alteration, ECs were treated with either soluble anti-AGE receptor (RAGE) IgG, or the MAPK inhibitors PD98059 and SB203580 before AGE-HSA administration. To further elucidate possible involvement of the ERK and p38 pathways in AGE-induced EC changes, adenovirus-carried recombinant constitutive dominant-negative forms of upstream ERK and p38 kinases, namely MEK1(A) and MKK6b(A), were pre-infected into ECs 24 h prior to AGE-HSA exposure. AGE-HSA induced actin cytoskeleton rearrangement, as well as EC hyperpermeability, in a dose and time-dependent manner. The effects were attenuated in cells pretreated with anti-RAGE IgG, PD98059 or SB203580, respectively. EC pre-infection with MEK1(A) and MKK6b(A) also alleviated the effect of AGEs. Furthermore, adenovirus-mediated administration of activated forms of either MEK1 or MKK6b alone induced rearrangement of F-actin and hyperpermeability. The results indicate that ERK and p38 MAPK play important roles in the mediation of AGE-induced EC barrier dysfunction associated with morphological changes of the F-actin. Copyright © Apmis 2006.
In recent years, coagulase-negative staphylococci such as Staphylococcus epidermidis have gained importance as nosocomial pathogens, especially in immunocompromised patients and prosthetic joint infections (PJIs). These infections are often long lasting and difficult to treat due to the production of bacterial biofilm and the transformation of the bacteria into a stationary growth phase. Rifampicin is able to penetrate the biofilm, but to reduce the risk of development of rifampicin resistance it should be used in combination with an additional antibiotic. In this study we used Etest to investigate the antimicrobial susceptibility of 134 clinical isolates of S.epidermidis obtained from PJIs to six oral antibiotics: doxycycline, rifampicin, linezolid, fusidic acid, clindamycin, and ciprofloxacin. We also performed synergy testing on doxycycline in combination with each of the remaining antibiotics. Ninety-three (69%) of the 134 isolates were susceptible to doxycycline, 94/134 (70%) to rifampicin, 56/134 (42%) to clindamycin, 25/134 (19%) to ciprofloxacin, 81/134 (60%) to fusidic acid, and 100% to linezolid. Thirty-two (80%) of the 40 isolates not fully susceptible to rifampicin were susceptible to doxycycline. Doxycycline in combination with each of the other investigated antibiotics exerted an additive effect on nearly half of the isolates, with the exception of clindamycin, which displayed an even higher percentage of additive effect (69%). To conclude, as the majority of the S.epidermidis isolates were susceptible to doxycycline, this antimicrobial agent may provide a potential alternative for combination therapy together with rifampicin.
We evaluated the diagnostic performance of two assays, one bead-based assay and one enzyme-linked immunosorbent assay (ELISA), for the determination of CXCL13 levels in cerebrospinal fluid (CSF) from patients with suspected Lyme neuroborreliosis (LNB). Patients investigated for LNB were retrospectively included (n = 132): 35 with definite LNB, 8 with possible LNB with CSF pleocytosis but normal antibody index (AI), 6 with possible LNB with elevated AI but no CSF pleocytosis and 83 non-LNB patients. CSF samples had been drawn before antibiotic treatment and were analysed for CXCL13 by Quantikine ELISA (Ramp;D Systems) and recomBead (Mikrogen). Receiver operating characteristic analyses based on the definite LNB and non-LNB groups revealed a best performance cut-off of 56 pg/mL for Quantikine and 158 pg/mL for recomBead (sensitivity and specificity 100% for both assays). When applying these cut-off levels on the study groups, the two assays performed equally well regarding sensitivity and specificity. In the group of patients with pleocytosis but negative AI, the majority of whom were children with short symptom duration, the CXCL13 analysis supported the LNB diagnosis in half of the cases. We consider CSF-CXCL13 analysis a useful diagnostic tool, in addition to Borrelia-specific AI, in laboratory diagnostics of LNB.
The aim of this study is to report the seroprevalence of SARS-CoV-2 antibodies in healthcare workers with various risk of occupational exposure in Kalmar County, Sweden, during the first year of the coronavirus disease 2019 (COVID-19) pandemic. We performed SARS-CoV-2 antibody measurements at four time points, from May 2020 to May 2021, in 401 healthcare workers (HCW) at seven hospital wards and two residential care facilities, with different risk of SARS-CoV-2 exposure. Overall, the prevalence of SARS-CoV-2 antibodies in HCW in Kalmar County was high compared to similar studies from other countries and increased from May 2020 to May 2021. Initially, 14% of the participants were SARS-CoV-2 seropositive. This number increased to 18% in September and 21% in December 2020. In May 2021, the prevalence of antibodies to nucleocapsid antigen had increased to 28%, while antibodies to spike protein had increased to 95% due to vaccination. A large variation in seroprevalence between different wards was detected and HCW in a COVID-19 designated ward had significantly higher seroprevalence than HCW working in wards without COVID-19 patients, with a risk ratio of 7.28, (95% CI 2.38-22.33) in May 2020. Our findings suggest a relationship between occupational COVID-19 exposure and seropositivity which implies that efficient hygiene routines for health- and social care workers are essential to avoid that COVID-19 care will constitute an occupational hazard.
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.
Ki-67 is a protein associated with cell proliferation which is expressed in all phases of the cell cycle except Go. In the present study, Ki-67 expression in 255 human colorectal adenocarcinomas was examined using immunohistochemistry with the monoclonal antibody MIB-1. One hundred and fifty-seven (62%) cases had more than 50% positive tumour cells and 98 (38%) cases less than 50%. The tumours showed a wide range of Ki-67 expression, from 13% to 90%, which indicated a variation in proliferative activity. There was no significant relationship between Ki-67 expression and sex, age, tumour location, Dukes' stage, growth pattern, differentiation, DNA content, S-phase fraction or survival (p > 0.05). In conclusion, the proliferative activity as measured by Ki-67 antibody was not related to clinicopathology and prognosis in colorectal cancer.
The purpose of this study was to assess the seroprevalence of C6 ELISA antibodies in healthy blood donors in Kalmar County, Sweden, in relation to age, sex and time of year (peak season vs off season). In addition, we wanted to assess serological status over time in a group of C6 ELISA seropositive blood donors. Sera were collected from 273 (131 women, 142 men) blood donors in autumn 2011 and 300 (144 women, 156 men) in winter 2014. All sera were analysed in the C6 ELISA and the results were interpreted according to the manufacturers instructions. The seroprevalence was 22% (females 16%, males 28%) in 2011 and 24% (females 15%, males 33%) in 2014. The seroprevalence was significantly higher in males and increased with age. The highest seroprevalence was observed among elderly men, 60-70 years old (46% in 2011 and 52% in 2014). No significant difference was detected in seropositivity between the samples collected in winter and autumn. All (34/34) seropositive blood donors followed over time remained seropositive at follow-up after 22-29 months. C6 ELISA seroprevalence in healthy blood donors is high in Kalmar County, thereby reducing the specificity of a positive test result regarding the clinical diagnosis of Lyme borreliosis (LB). Although C6 seroprevalence appears not to be affected by seasonal sample time, it varies greatly with age and sex. A careful evaluation of pre-test probability is therefore of the utmost importance in the clinical diagnosis of LB, especially in elderly men. We suggest that colleagues in other endemic regions also consider initiating similar evaluations to optimize the laboratory and clinical diagnosis of LB in relation to age and sex.
The rapid identification of the etiological agent of microbial infections can bring about both clinical and financial benefits. Thus, fast and generally applicable classification methods are needed that will enable us to rapidly distinguish pathogenic bacteria from commensals or saprophytic bacteria found in the same habitat. We here show that provisional classification of bacterial isolates can be performed on a large scale based on 16S rRNA sequence comparisons using PyrosequencingÖ, a recently described real-time DNA sequence analysis technique, and the concept of signature matching. The probes we have developed, together with the new technology, will enable early diagnosis of specific pathogens, which is critical for the rational use of antimicrobial therapy in clinical medicine.
To investigate whether arbitrarily primed (AP)-PCR and/or 16S rDNA sequencing could be used as rapid methods for epidemiological typing and species identification of clinical Burkholderia isolates from patients with cystic fibrosis (CF), a total of 39 clinical B. cepacia isolates, including 33 isolates from 14 CF patients, were fingerprinted. ERIC-2 primer was used for AP-PCR. The AP-PCR clustering analysis resulted in 14 different clusters at a 70% similarity level. The AP-PRC patterns were individual despite considerable similarities. To sequence rDNA, a broad-range PCR was applied. The PCR product included four variable loops (V8, V3, V4 and V9) of the 16S ribosomal small subunit RNA gene. The multiple sequence alignment produced 12 different patterns, 5 of them including more than one isolate. Heterogeneity of the bases in the V3 region, indicating the simultaneous presence of at least two different types of 16S rRNA genes in the same cell, was revealed in 10 isolates. Most of the CF patients were adults who had advanced disease at follow-up. Both the sequencing and the AP-PCR patterns revealed genetic heterogeneity of isolates between patients. According to the results obtained, AP-PCR could advantageously be used for epidemiological typing of Burkholderia, whereas partial species identification could effectively be obtained by sequencing of the V3 region of the 16S RNA gene.
Objectives: To investigate the degree of bacterial contamination in the sternal wound during cardiac surgery and the sternal skin flora after operation in order to increase our understanding of the pathogenesis of sternal wound infections. Design: Prospective study where cultures were taken peri- and postoperatively from sternal wounds and skin. Setting: University Hospital. Patients: 201 cardiac surgery patients. Results: 89% of the patients grew bacteria from the subcutaneous sternal tissue. 98% of the patients showed bacterial growth on the surrounding skin at the end of the operation. We found both commensal and nosocomial bacteria in the sternal wound. These bacteria had different temporal distribution patterns. Coagulase-negative staphylococci (CoNS) and Propionibacterium acnes (PA) were by far the most prevalent bacteria during and after the operation. Furthermore, 41% of patients had more than 10 000 CFU/pad CoNS on the skin. There was no correlation between length of operation and number of bacteria. Men displayed higher bacterial counts than women on the skin. Conclusion: Skin preparation with ethanol/chlorhexidine is unable to suppress the physiological skin flora for the duration of a heart operation. A decrease of CoNS and PA postoperatively can be caused by competitive recolonisation of commensal and nosocomial bacteria.
Whether bacterial vaginosis (BV) is acquired from an endogenous or an exogenous source is subject to controversy. Despite findings of an association between sexual behaviour and BV, some data indicate that BV is not a sexually transmitted infection in the traditional sense, while other data indicate that BV is an exogenous infection. A third aspect of BV is its tendency to go unnoticed by affected women. All of this will have a strong impact on how physicians view the risks of asymptomatic BV This review focuses on whether or not BV should be regarded as a sexually transmitted infection (STI), its role in postoperative infections and pelvic inflammatory disease (PID), and on whether or not treatment of BV during pregnancy to reduce preterm delivery should be recommended. The reviewed studies do not lend unequivocal support to an endogenous or exogenous transmission of the bacteria present in BV For women undergoing gynaecological surgery such as therapeutic abortion, the relative risk of postoperative infection is clearly elevated (approx. 2.3-2.8). A weaker association exists between BV and pelvic inflammatory disease. Data on treatment of BV as a way of reducing preterm delivery are inconclusive and do not support recommendations for general treatment of BV during pregnancy. The discrepant associations between BV and preterm birth found in recent studies may be explained by variations in immunological response to BV. Genetic polymorphism in the cytokine response - both regarding the TNF alleles and in interleukin production - could make women more or less susceptible to BV, causing different risks of preterm birth. Thus, studies on the vaginal inflammatory response to microbial colonization should be given priority. Copyright © APMIS 2005.
The syndrome bacterial vaginosis (BV) is characterized by a disturbed vaginal microflora in which the normally occurring lactobacilli yield quantitatively to an overgrowth of mainly anaerobic bacteria. As BV is a possible cause of obstetrics complications and gynaecological disease - as well as a nuisance to the affected women - there is a strong impetus to find a cure. In BV treatment studies, the diagnosis criteria for diagnosis of BV vary considerably and different methods are used for cure evaluation. The design of study protocols varies and there is no consensus respecting a suitable time for follow-up visits. For the purpose of this review, available data were recalculated for 4-week post treatment cure rates. For oral metronidazole the 4-week cure rate was found not to exceed 60-70%. Treatment regimens with topical clindamycin or topical metronidazole have the same cure rates. It can thus be said that no sound scientific basis exists for recommending any particular treatment. There is no evidence of beneficial effects on BV engendered by partner treatment, or by addition of probiotics or buffered gel. Long-term follow-up (longer than 4 weeks) shows a relapse rate of 70%. With a primary cure rate of 60-70%, and a similar relapse rate documented in the reviewed literature, clinicians simply do not have adequate data for determining treatment or designing clinical studies. This is unfortunate since - apart from the obvious patient benefits - clinical studies can often serve as a guide for more basic studies in the quest for underlying disease mechanisms. In the case of BV there is still a need for continued basic studies on the vaginal flora, local immunity to the flora and host-parasite interactions as an aid when designing informative clinical studies. Copyright © APMIS 2005.
Inaccuracies in medical language are detrimental to communication and statistics in medicine, and thereby to clinical practice, medical science and public health. The purpose of this article is to explore inconsistencies in the use of some medical terms: urinary tract infection, bacteriuria and urethral syndrome. The investigated literature was collected from medical dictionaries, textbooks, and articles indexed in Medline«. We found various practices regarding how the medical terms should be defined, and had great difficulty in interpreting the status of the statements under the heading of 'definition'. The lesson to be learned, besides a reminder of the importance of clearly defined medical concepts, is that it must be explicitly stated whether what is presented as a definition is to be considered as defining criterion, as recognising criterion or as characteristic of the disease entity.
P120-catenin plays an important role in cell adhesion and signalling transduction though the function of its isoforms is unclear. The aim of this study was to examine the expression of p120-catenin isoforms in lung cancer and investigate their relationship to clinicopathological factors in lung squamous cell carcinomas (SCCs) and adenocarcinomas. The expression patterns of p120-catenin in lung cancer tissues and lung cancer cells were examined by p120-catenin immunofluorescence, Western blot, and reverse transcription- polymerase chain reaction (RT-PCR). Clear and continuous red fluorescence of p120-catenin is displayed at the cell membrane of corresponding normal bronchial epithelial cells, but not in lung cancer tissues that show reduction or absence of membrane expression of p120-catenin or cytoplasmic accumulation of p120-catenin. Compared with corresponding normal lung tissues, lung cancer tissues have significantly lower levels of p120-catenin proteins (P<0.001) and mRNA (P<0.001). The isoforms 1 (120 kD) and 3 (100 kD) proteins were major isoforms of p120-catenin expressed in normal lung tissues, which were significantly reduced in lung cancer samples (P=0.001 and P<0.001, respectively). The mRNA of p120-catenin isoforms 1.2, 1.3, 2.3, 3.1 and 3.3 was detected in corresponding normal lung tissues, but was significantly absent in lung cancer samples (P<0.001 and P=0.001, respectively). Furthermore, p120-catenin isoform 1 is negatively associated - whereas p120-catenin isoform 3 is positively associated - with lymph node metastasis. We conclude that reductions of isoforms 1 and 3 may play different roles in metastatic progression of human lung cancer. © Apmis 2007.
In the present study, 10 azithromycin-resistant Neisseria gonorrhoeae isolates from 6 Swedish male patients in 2004, 3 sporadic Swedish azithromycin-resistant N. gonorrhoeae isolates from recent years and one Swedish N. gonorrhoeae isolate from 2003 that was susceptible to azithromycin but assigned the same serological variant (serovar), i.e. IB-37, as the isolates from 2004 were included. The isolates were characterized phenotypically using antibiograms and serovar determination and genetically with pulsed-field gel electrophoresis (PFGE), entire porB gene sequencing and N. gonorrhoeae multiantigen sequence typing (NG-MAST). The epidemiological information and the results of the thorough phenotypic characterisation and genetic characterisation identified the first presumed domestic transmission of one azithromycin-resistant N. gonorrhoeae strain in Sweden in 2004. This stresses the need for continuous surveillance of the antibiotic susceptibility of N. gonorrhoeae in order to identify emergence of new resistance, monitor the changing patterns of the susceptibility, and be able to update treatment recommendations on a regular basis.
Autopsies constitute a valuable feedback to the healthcare chain to achieve improvements in quality of care and cost effectiveness. This review describes post-mortem imaging, which has emerged as an important part of the pathology toolbox. A broad range of visualization aspects within post-mortem imaging are covered. General state-of-the-art overviews of the components in the visualization pipeline are complemented by in-depth descriptions of methods developed by the authors and our collaborators. The forensic field is represented and related to, as it is spearheading much development in postmortem imaging. Other topics are workflow, imaging data acquisition, and visualization rendering technology. All in all, this review shows the mature state of visual analysis for a non-or minimal-invasive investigation of the deceased patient.
The aim of this study was to test the hypothesis that Staphylococcus epidermidis isolated from prosthetic joint infections (PJIs) differs from S.epidermidis isolated from normal flora in terms of its capacity to induce activation of caspase-1 and release of IL-1 in human neutrophils. The amount of active caspase-1 was determined over 6h by detecting Ac-YVAD-AMC fluorescence in human neutrophils incubated with S.epidermidis isolates from PJIs (ST2) or normal flora. The amount of IL-1 was detected by ELISA in neutrophil supernatants after 6h of incubation. Mean IL-1 release was lower after incubation with S.epidermidis from PJIs compared to isolates from normal flora, but no statistically significant difference was found in active caspase-1. Substantial inter-individual differences in both active caspase-1 and IL-1 were noted. These results suggest that evasion of innate immune response, measured as reduced capacity to induce release of IL-1 from human neutrophils, might be involved in the predominance of ST2 in S.epidermidis PJIs, but that other microbe-related factors are probably also important.
Based on partial sequence analysis of PCR-amplified 16S rDNA variable V6 regions of 14 enterococcal type strains, Enterococcus faecalis, Enterococcus mundtii, Enterococcus gallinarum, Enterococcus avium, Enterococcus raffinosus and Enterococcus saccharolyticus showed characteristic sequence motifs which made it possible to separate them into six individual species lines. Furthermore, two species cluster groups could be identified, including (i) Enterococcus faecium, Enterococcus durans, Enterococcus hirae, Enterococcus malodoratus, and (ii) Enterococcus casseliflavus/Enterococcus flavescens, Enterococcus pseudoavium, Enterococcus dispar and Enterococcus sulfureus. There were identical DNA sequences in the V6 region within each group. Temporal temperature gradient gel electrophoresis (TTGE) of the PCR products from 16 type strains, 12 enterococcal reference strains and 8 clinical isolates revealed that a single nucleotide divergence in DNA sequences was sufficient for separation, identification and division of the studied enterococcal strains into corresponding TTGE profiles. It was concluded that partial DNA sequence analysis and TTGE profiling of PCR-amplified 16S rDNA variable V6 regions provide useful tools for the identification of clinically important Enterococcus spp.
Extended-spectrum β-lactamases (ESBLs) are often mediated by bla-SHV, blaTEM and blaCTX-M genes in Enterobacteriaceae and other Gram-negative bacteria. Numerous molecular typing methods, including PCR-based assays, have been developed for their identification. To reduce the number of PCR amplifications needed we have developed a multiplex PCR assay which detects and discriminates between bla-SHV, blaTEM and blaCTX-M PCR amplicons of 747, 445 and 593 bp, respectively. This multiplex PCR assay allowed the identification of bla-SHV, blaTEM and blaCTX-M genes in a series of clinical isolates of Enterobacteriaceae with previously characterised ESBL phenotype. The presence of blaSHV, blaTEM and blaCTX-M genes was confirmed by partial DNA sequence analysis. Apparently, the universal well-established CTX-M primer pair used here to reveal plasmid-encoded blaCTX-M genes would also amplify the chromosomally located K-1 enzyme gene in all Klebsiella oxytoca strains included in the study.
A multiplex PCR assay for the detection of vancomycin resistance (van) genes in enterococci was established. Primers targeting the 16S rRNA gene were included in the reaction mixture. Multiple-primer DNA sequencing of the PCR products provided species identification through partial nucleotide sequences of 16S rRNA genes, as well as confirmation of the correct identification of vanA, vanB, vanC-1, and vanC-2/3 genotypes. Thirty-nine enterococcal clinical isolates and type strains were examined for the presence of vancomycin resistance determinants. Twelve other isolates from a clinical reference collection (some of them having vanA, vanB, vanC-1, or vanC-2/3 genotypes) were used as controls. Hybridization and partial DNA sequence analysis of multiplex PCR products revealed that none of the clinical isolates had a vanA genotype and only one had a vanB genotype, vanC- 1 was found in three clinical isolates, and vanC-2/3 in one. Results obtained with the reference and type strains were in agreement with earlier results.
Broad range PCR amplification and genus-specific 16S ribosomal DNA hybridization was used to demonstrate that Chlamydia, Helicobacter and Mobiluncus hybridization probes, located within variable regions V3, V4, and V9 of the 16S rDNA, specifically bound to the corresponding PCR product obtained from pure cultures of the three genera. The sensitivity of the assay was determined by analysis of C. trachomatis serially diluted in urine. The detection limit was 1–10 elementary bodies using a hybridization probe derived from the variable region V3 of the 16S rRNA gene. A PCR product was furthermore formed in urine specimens not containing C. trachomatis, showing amplification of chlamydia also in the presence of DNA from the resident urethral flora that competes for annealing sites. Analysis of a restricted number of male urine specimens using the C. trachomatis-specific probe showed complete agreement with culture and a commercially available PCR kit. Our method not only has the capacity to detect C. trachomatis in microbiologically mixed urine samples but also the potential advantage of identifying other bacterial pathogens from the same PCR product by varying the hybridization probes.
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.
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.
Staphylococcus epidermidis often causes foreign-body infections such as those associated with hip prostheses, but the underlying pathogenic mechanisms are not fully understood. We performed spectrophotometry to study the ability of S. epidermidis to bind to immobilised fibrinogen, fibronectin, vitronectin, and collagen. The strains were isolated from infected hip prostheses or from normal flora and the well-known protein-binding strain Staphylococcus aureus Cowan was used as positive control. We also analysed the interaction between neutrophils and a fibrinogen-bound prosthesis-derived strain of S. epidermidisby measuring chemiluminescence to determine the neutrophil oxidative response and binding of annexin V to indicate neutrophil apoptosis. We found that binding of S. epidermidis to extracellular matrix proteins varied under different growth conditions, and that prosthesis isolates adhered better to vitronectin than did strains from normal flora. The oxidative response caused by fibrinogen-bound S. epidermidis was not above the background level, which was in marked contrast to the distinct response induced by fibrinogen-associated S. aureus Cowan. Furthermore, fibrinogen-adhering S. epidermidis retarded neutrophil apoptosis. We conclude that surface-bound S. epidermidis induces only a weak inflammatory response, which in combination with the ability of the adherent bacteria to retard neutrophil apoptosis may contribute to low-grade inflammation and loosening of prostheses.
S. epidermidis is the most common isolate in foreign body infections. The aim of this study was to understand why S. epidermidis causes silent biomaterial infections. In view of the divergent inflammatory responses S. epidermidis and S. aureus cause in patients, we analyzed how they differ when interacting with human neutrophils. Neutrophils interacting with S. epidermidis strains isolated either from granulation tissue covering infected hip prostheses or from normal skin flora were tested by measuring the oxidative response as chemiluminescence and apoptosis as annexin V binding. Different S. aureus strains were tested in parallel. All S. epidermidis tested were unable to modulate the oxidative reaction in response to formyl-methionyl-leucyl-phenylalanine (fMLP) and did not provoke, but rather inhibited, apoptosis. In contrast, some S. aureus strains enhanced the oxidative reaction, and this priming capacity was linked to p38-mitogen-activated-protein-kinase (p38-MAPK) activation and induction of apoptosis. Our results may explain why S. epidermidis is a weak inducer of inflammation compared to S. aureus, and therefore responsible for the indolent and chronic course of S. epidermidis biomaterial infections.
The lantibiotic duramycin (Moli1901, Lancovutide) has been suggested as a drug of choice in the treatment for cystic fibrosis (CF). It has been proposed that duramycin may stimulate chloride secretion through Ca²(+) -activated Cl⁻ channels (CaCC). We investigated whether duramycin exhibited any effect on Cl⁻ efflux and intracellular Ca²(+) concentration ([Ca²(+)](i)) in CF and non-CF epithelial cells. Duramycin did stimulate Cl⁻ efflux from CF bronchial epithelial cells (CFBE) in a narrow concentration range (around 1 μM). However, 100 and 250 μM of duramycin inhibited Cl⁻ efflux from CFBE cells. An inhibitor of the CF transmembrane conductance regulator (CFTR(inh)₋₁₇₂) and a blocker of the capacitative Ca²(+) entry, gadolinium chloride, inhibited the duramycin-induced Cl⁻ efflux. No effect on Cl⁻ efflux was observed in non-CF human bronchial epithelial cells (16HBE), human airway submucosal gland cell line, human pancreatic epithelial cells, CF airway submucosal gland epithelial cells, and CF pancreatic cells. The [Ca²(+)](i) was increased by 3 μM duramycin in 16HBE cells, but decreased after 1, and 3 μM of duramycin in CFBE cells. The results suggest that the mechanism responsible for the stimulation of Cl⁻ efflux by duramycin is mainly related to unspecific changes of the cell membrane or its components rather than to effects on CaCC.
Oxidized low-density lipoprotein (LDL) diminishes NO production from activated macrophages. The interaction between LDL and inactivated macrophages is neglected and controversial. This study examines the effect of LDL, 7-oxysterols and iron compounds on NO production in unstimulated J774 macrophages. J774 cells and human umbilical vein endothelial cells (HUVEC) were either incubated for 24 h with native LDL (LDL) or ultraviolet (UV)-oxidized LDL (UVoxLDL), in the absence or presence of an inducible nitric oxide synthase (iNOS)- or an endothelial constitutive nitric oxide synthase (eNOS)-inhibitor. J774 cells were also incubated with lipopolysaccharide (LPS), in the absence or presence of an iNOS- or an eNOS-inhibitor. Nitrite was analysed as a marker of NO production. The mRNA levels of iNOS were evaluated by reverse transcriptase polymerase chain reaction. LDL and UVoxLDL significantly increased NO production from unstimulated J774 macrophages. This increase in NO was accompanied by enhanced expression of iNOS mRNA, and was inhibited by the iNOS inhibitor. Furthermore, NO production was elevated and angiotensin-converting enzyme (ACE) activity was reduced in HUVEC following the exposure to LDL and UVoxLDL. In conclusion, LDL may serve as an important inflammatory activator of macrophages and HUVEC, inducing inducible nitric oxide production but diminishing ACE. After its oxidation, this function of LDL may be further enhanced and may contribute to the regulation and progression of atheroma formation.
A functional dichotomy between Th1- and Th2-type immune responses has been suggested. This study was performed to investigate whether rheumatoid arthritis (RA), a disease with indications of Th1-deviated immune activation, is inversly related to atopic conditions which are Th2-mediated. Two hundred and sixty-three adult cases of RA, fulfilling the American Rheumatism Association (ARA) 1987 Revised Classification Criteria for RA, were identified in 1995 and compared with 541 randomly selected population referents. The presence of atopic manifestations was established through a postal questionnaire and by demonstrating circulating IgE antibodies to common allergens. RA was inversely associated with certain manifestations of rhinitis, which were regarded as the most reliable indicators of atopic disease in the present study. However, no negative association was seen between RA and asthma and eczema, respectively. The main results give some support for an inverse relationship between RA and rhinitis. The prevalence of circulating IgE antibodies was however similar in cases and controls, suggesting that the T-cell commitment mainly occurs in the affected organs.
Controlling the spread of vancomycin-resistant enterococci (VRE) is an important task in hospital epidemiology. Pulsed-field gel electrophoresis (PFGE) has become the golden standard for molecular epidemiological characterisation of enterococcal isolates. For separation of DNA fragments by PFGE, different electrophoresis conditions have been recommended, but none of these protocols allows a satisfactory separation of both small and large DNA fragments of enterococci simultaneously. In this study we have speeded up the preparation of chromosomal DNA and defined new electrophoresis conditions that enhance separation of small and large DNA fragments for subtyping of enterococci with a 24 h PFGE.
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.
The aim of this study was to determine the accuracy of a wet-mount bacterial morphology scoring (BMS) system and Nugent's Gram stain analysis for the diagnosis of bacterial vaginosis, using Amsel's criteria as the gold standard. The three diagnostic criteria were assessed independently. The BMS diagnosis was based on a scoring system which weighed the number of small bacterial morphotypes regarded as typical of bacterial vaginosis against lactobacillary morphotypes in phase-contrast microscopy of wet-mount preparations. Three groups of non-pregnant women attending either because of vaginal discharge, other genitourinary symptoms, or for a routine check-up, and a group of pregnant women attending for antenatal care were studied. The diagnostic accuracy was measured by sensitivity, specificity, positive and negative predictive values, and likelihood ratio. The accuracy of the BMS diagnosis was substantially high in all of the examined groups (LR 15.4-20.3). The accuracy of the Gram stain diagnosis was lower (LR 7.6-10.9). In the total material, the accuracy of the BMS diagnosis was higher than that of the Nugent's Gram staining. Intra- and inter-observer reproducibility of all three criteria applied was high. We propose greater routine use of the new BMS diagnosis for point-of-care testing in family practice as well as in research and in microbiology laboratories.