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Biomedical subjects

M F Peeters

Publications and source records attributed to M F Peeters.

At least 19 recordsLinked to original sources
PubMed2007

Evaluation of the SAS Legionella Test, a new immunochromatographic assay for the detection of Legionella pneumophila serogroup 1 antigen in urine.

This study evaluated a new immunochromatographic assay (SAS Legionella Test) for its ability to detect Legionella pneumophila serogroup 1 antigen in urine. Results were compared with those obtained using the Binax Now urinary antigen test. Sensitivity and specificity were estimated as 82.9% and 99.0%, respectively, for the SAS Legionella Test, and 91.4% and 100%, respectively, for the Binax Now urinary antigen test. The sensitivity of both tests increased to 97.1% (p 0.009) and 94.2% (p 0.7), respectively, if the tests were examined after 1 h.

Antigens, Bacterial↗
PubMed2005

Estimation of minimum infection rates with Legionella pneumophila in an exposed population.

The distribution of antibody levels to Legionella (L.) pneumophila (serotypes 1-7) was compared between subjects who worked near the source of a large outbreak of Legionnaires' disease (n=668) and a population sample of comparable age (n=480). In a previous analysis of these data, it was estimated that 80% of those working near the source were infected with L. pneumophila. However, the estimation procedure implicitly assumes that the probability of infection does not depend on the antibody level of a person before exposure. This is questionable, as antibodies could protect against infection. We have now estimated the minimum value consistent with the data on the number of infected persons. We observed that a minimum of 40% [95% confidence interval (CI) 32-48] of those working near the source and 13% (95% CI 8-18) of those working further away were infected with L. pneumophila. Implications of these findings for design options in future research are discussed.

Adolescent↗
PubMed2005

Community-acquired pneumonia caused by Legionella longbeachae in an immunocompetent patient.

Reported here is the case of a previously healthy 67-year-old man who was admitted to the intensive care unit with pneumonia caused by Legionella longbeachae. The organism was identified in sputum and serum by 16S rRNA-based PCR assay and sequence-based typing. One acute serum sample produced a single elevated IgM antibody titer of 1:512 against non-pneumophila Legionella spp. The patient fully recovered following the initiation of appropriate antibiotic treatment. Since most current laboratory tests for Legionella spp. cannot detect infections caused by non-pneumophila Legionella spp., culture on Legionella-selective media or PCR should be considered when diagnosing severe pneumonia of unknown etiology.

Community-Acquired Infections↗
PubMed2005

Erythromycin resistance in the commensal throat flora of patients visiting the general practitioner: a reservoir for resistance genes for potential pathogenic bacteria.

The prevalence and mechanism of erythromycin resistance in commensal throat streptococci was determined from October 2000 until December 2002 as part of an ongoing study of the NIVEL in general practice patients (N=678). Resistance prevalence for 1mg/L and 16 mg/L erythromycin was 57% and 20%, respectively. The percentage of total commensal flora resistant within each patient ranged from 1% to 100% (median, 1%). mefA was predominantly found among isolates on the 1mg/L plates, and ermB was found in 64% of the isolates on the 16 mg/L plates. Erythromycin resistance was transferred from a commensal isolate to Streptococcus pneumoniae with a frequency of 1 x 10(-9). Commensal streptococci of general practice patients in The Netherlands form a large reservoir of transferable erythromycin resistance (genes) for potential pathogenic microorganisms.

Anti-Bacterial Agents↗
PubMed2005

No evidence of Legionella infection in general practice patients presenting with acute respiratory infections in The Netherlands.

The role of Legionella spp. in the aetiology of acute respiratory infections (ARIs) is largely unknown. In this case-control study, conducted in a general practitioner setting during 2000 and 2001, nose and throat samples from patients presenting with ARIs (n = 230) and controls (n = 200) were analysed for the presence of Legionella spp. by real-time PCR. Legionella DNA was not detected in any of the cases or controls. Thus, Legionella spp. do not seem to play a role in patients presenting with ARIs, nor were they present in patients who visited their general practitioner for complaints other than ARIs.

Acute Disease↗
PubMed2005

Community-acquired pathogens associated with prolonged coughing in children: a prospective cohort study.

A 2-year prospective study was performed of children with prolonged coughing to investigate the frequency of different respiratory pathogens, the rate of mixed infections, and possible differences in severity of disease between single and mixed infections. Sera from 135 children (136 episodes of prolonged coughing lasting 1-6 weeks) were tested for antibodies to different viruses and bacteria. Swabs were taken for culture and PCR to detect different viral and bacterial pathogens. One or more pathogens were found in 91 (67%) patients. One infectious agent was found in 49 (36%) patients, two agents in 35 (26%) patients, and more than two agents in seven (5%) patients. The most frequent pathogens encountered were rhinovirus (n = 43; 32%), Bordetella pertussis (n = 23; 17%) and respiratory syncytial virus (n = 15; 11%). The most frequent mixed infection was B. pertussis and rhinovirus (n = 14; 10%). No significant differences in clinical symptoms were observed between patients with or without pathogens; however, patients with mixed infections were significantly older. There was a strong seasonal influence on the number of infections, but not on the number of mixed infections. In children with prolonged coughing, there was a high frequency of mixed infections regardless of the season. However, mixed infection was not associated with increased disease severity. No clinical symptoms were found that allowed discrimination between specific pathogens.

Antibodies, Bacterial↗
PubMed2004

Real-time PCR assay using fine-needle aspirates and tissue biopsy specimens for rapid diagnosis of mycobacterial lymphadenitis in children.

A real-time PCR assay was developed to diagnose and identify the causative agents of suspected mycobacterial lymphadenitis. Primers and probes for the real-time PCR were designed on the basis of the internal transcribed spacer sequence, enabling the recognition of the genus Mycobacterium and the species Mycobacterium avium and M. tuberculosis. The detection limit for the assay was established at 1,100 CFU/ml of pus, and the specificity tests showed no false-positive reaction with other mycobacterial species and other pathogens causing lymphadenitis. From 67 children with suspected mycobacterial lymphadenitis based on a positive mycobacterial skin test, 102 samples (58 fine-needle aspirates [FNA] and 44 tissue specimens) were obtained. The real-time PCR assay detected a mycobacterial infection in 48 patients (71.6%), whereas auramine staining and culturing were positive for 31 (46.3%) and 28 (41.8%) of the patients. The addition of the real-time PCR assay to conventional diagnostic tests resulted in the recognition of 13 more patients with mycobacterial disease. These results indicate that the real-time PCR is more sensitive than conventional staining and culturing techniques (P = 0.006). The M. avium-specific real-time PCR was positive for 38 patients, and the M. tuberculosis-specific real-time PCR was positive for 1 patient. Analysis of 27 patients from whom FNA and tissue biopsy specimens were collected revealed significantly more positive real-time PCR results for FNA than for tissue biopsy specimens (P = 0.003). Samples from an age-matched control group of 50 patients with PCR-proven cat scratch disease were all found to be negative by the real-time PCR. We conclude that this real-time PCR assay with a sensitivity of 72% for patients with lymphadenitis and a specificity of 100% for the detection of atypical mycobacteria can provide excellent support for clinical decision making in children with lymphadenitis.

Base Sequence↗
PubMed2003

An outbreak of Legionnaire's disease among visitors to a fair in Belgium in 1999.

This paper describes an outbreak of Legionnaire's disease at Kapellen in Belgium among visitors of the annual fair. The investigation started on 13th November 1999 after a respiratory physician notified the health authorities of the province of Antwerp of presumptive cases of legionellosis. The annual commercial fair at Kapellen, a small town in northern Belgium, was held 10 days previously and attracted 50,000 visitors. Stand employees (professionals or volunteers), technical staff of the hall and visitors at the fair were affected cases. An exploratory case-control study was conducted to trace the source of the epidemic. To complete the inventory study and to evaluate other risk factors, a cohort study of exhibitors and staff was conducted. Ninety-three people met the case definition, 41 of whom were considered as confirmed, 14 as presumptive cases and 38 as possible/clinical cases. Five people died. Further testing at the reference laboratory confirmed all strains to be Legionella pneumophila serogroup 1. The sensitivity for culture was low (29.2%), and sensitivity for seroconversion was high (90.9%). For urinary antigen test, a sensitivity with Biotest EIA of 65.6% was found, and the sensitivity of polymerase chain reaction (PCR) was 85.7%. In all cases, the individual had visited the fair. Those individuals working in the central areas of the tent, near the aerosol-producing devices, were at higher risk of disease. Legionella was detected by PCR on swabs of the surfaces of the whirlpool. Although not fully proven, an aerosol-producing device was the most probable source of the outbreak.

Aerosols↗
PubMed2003

Extraction of Chlamydia pneumoniae DNA from vascular tissue for use in PCR: an evaluation of four procedures.

The objective of this study was to compare four procedures for Chlamydia pneumoniae DNA extraction from vascular tissue. The NucliSens Kit, the QIAamp tissue DNA MiniKit, buffer-saturated phenol and the Geneclean II Kit were evaluated, based on the yield of recovered DNA, using PCR to detect C. pneumoniae in vascular tissue. The QIAamp tissue procedure had the highest detection level (0.004 inclusion-forming units/sample). All methods, except NucliSens (70 min), had a short handling time (30-40 min). Costs varied from 0.5 to 3.2 Euro.

Chlamydia Infections↗
PubMed2003

Nosocomial influenza infection among post-influenza-vaccinated patients with severe pulmonary diseases.

OBJECTIVES: To report an outbreak of nosocomial influenza in thirteen out of twenty-two admitted patients suffering from severe lung emphysema. METHODS: Acute-phase and convalescent serum samples of nine patients were collected. An antihaemagglutinin assay was performed to detect a rise in antibodies against influenza A virus. Further information about vaccination history of the patients and healthcare workers was included. RESULTS: The majority of these twenty-two patients was vaccinated with a trivalent vaccine six months earlier. The immunological response showed that the influenza A (H3N2) strain which caused these infections is similar to the vaccine strain A/Sydney/5/97. CONCLUSIONS: The staff of our institute which was not systematically vaccinated may have been the source of infection. The time elapsed between the vaccination and the infection is the probable explanation of this event.

Aged↗
PubMed2002

Pan-European study on culture-proven Legionnaires' disease: distribution of Legionella pneumophila serogroups and monoclonal subgroups.

This pan-European study included unrelated strains of Legionella pneumophila obtained from 1335 cases of Legionnaires' disease. The isolates were serotyped into the serogroups 1 to 15 by monoclonal antibodies (MAb) and/or rabbit antisera. Additionally, MAb subgrouping was undertaken for isolates belonging to serogroups 1, 4, and 5. Monoclonal types of serogroup 1 were subdivided as having, or not having, the virulence-associated epitope recognized by the MAb 3/1 (Dresden Panel). This epitope is not present on strains belonging to any other serogroups. Taking all Legionella incidents together, MAb 3/1-positive cases were most frequent (66.8%); 11.7% of the isolates belonged to MAb 3/1-negative serogroup 1 subgroups and 21.5% to other serogroups, with serogroups 3 and 6 predominating. Among all serotypes discriminated in this study, monoclonal subtype Philadelphia was the most frequent. If categories of infection were considered, the proportion of MAb 3/1-negative strains differed significantly ( P<0.0005) between community-acquired cases (139/510; 27.3%) and travel-associated (42/295; 14.2%) or hospital-acquired infections (176/329; 53.5%). Moreover, taking distribution in different European areas into account, the proportion of MAb 3/1-negative strains was significantly higher in the Scandinavian region than in the Mediterranean countries or the UK for both community-acquired (48.7% vs. 18.6% or 12.0%; P<0.0005) and nosocomial cases (87.7% vs. 32.6% or 52.6%; P</=0.0007).

Animals↗
PubMed2002

Chlamydia pneumoniae, systemic inflammation and the risk of venous thrombosis.

Inflammatory mediators are involved in activation of the coagulation system, and elevated plasma concentrations of IL-6 and IL-8 are associated with an increased risk of venous thrombosis. Using serologic and molecular biologic tests, we investigated in a case-control study on patients with recurrent venous thrombosis the association between Chlamydia (C) pneumoniae and venous thrombosis and we evaluated the relation between C. pneumoniae serology and the cytokines IL-6 and IL-8. The presence of C. pneumoniae antibody titers > or = 1:16 was not associated with an increased risk of venous thrombosis (odds ratio 0.8 95% CI, 0.4-1.7). Circulating C. pneumoniae-DNA was detected in only one patient and two control subjects. IgG antibody titers against C. pneumoniae were not correlated with the concentrations of IL-6 and IL-8. These results indicate that the inflammatory process shown in patients with venous thrombosis is not related to C. pneumoniae.

Adult↗
PubMed2002

Sensitivity and specificity of three new commercially available Chlamydia trachomatis tests.

In order to determine the value of new Chlamydia trachomatis (Ct) specific tests for routine serological diagnosis of Ct infections, we evaluated several commercially available assays (C. trachomatis enzyme immunoassay (EIA), Labsystems (CtL); SeroCT, Savyon (CtS); pELISA, Medac (CtMp)) in various study populations. The prevalence of C. trachomatis-specific IgA antibodies in a blood donor population (n = 443) as determined by the peptide based tests CtL, the CtS and the CtMp was 5%, while for IgG antibodies this was 6% (CtL and CtS) and 12% (CtMp) respectively. Prevalence was negatively correlated with age, concording with C. trachomatis specificity. None of the three tests showed significant titre rises in serum samples taken from patients with a proven infection of Chlamydia pneumoniae (n = 22), indicating species-specificity for all three tests. In patients with a polymerase chain reaction proven (n = 324) Ct infection, 75%, 70% and 68% were positive for IgG and 45%, 38% and 47%, positive for IgA as determined by the CtMp, CtL and CtS respectively. We conclude that the new synthetic peptide-based EIA tests are able to detect species-specific Ct antibodies, which are strongly correlated to (active) infection.

Adult↗
PubMed2002

Tubal factor pathology caused by Chlamydia trachomatis: the role of serology.

One of the causes of infertility in females is tubal pathology as a result of pelvic inflammatory disease (PID) caused by Chlamydia trachomatis (Ct). Diagnosis and identification of patients is hampered by the lack of rapid, easy, sensitive and specific methods. The introduction of Ct-specific enzyme-linked immunosorbent assay (ELISA) tests, based upon synthetic peptides may subsequently increase the sensitivity and specificity for the detection of tubal factor infertility caused by Ct. In order to determine the value of these tests for serological diagnosis of Ct infections, we evaluated several commercially available assays (C. trachomatis enzyme immunoassay (EIA), Labsystems (CtL); SeroCT, Savyon (CtS); pELISA, Medac (CtMp); and a reference assay rELISA, Medac (CtMr)) in two study populations. The first group consisted of 134 female patients with infertility problems. Tubal factor infertility was observed in 85 of these patients (63%). A higher % positivity was found for Ct-specific IgG for the CtL, CtS and CtMp, 41% vs 10%, 57% vs 18% and 55% vs 25% respectively as compared to patients with infertility due to other problems. A similar trend was observed for Ct-specific IgA. The specificity of Ct-specific IgA and IgG in this patient group varied between 92 to 98% and 76 to 90%, respectively. The second group consisted of 107 consecutive gynaecology patients with fertility problems or suspected PID. In this particular patient group, the specificity of the peptide based tests were around 80% and 90% for Ct-specific IgA and 75% and 85% for Ct-specific IgG, respectively. The negative predictive values exceeded 90%, while the positive predictive values varied from 30% to 47% for Ct-specific IgA and was around 30% for Ct-specific IgG. Testing Ct-specific IgG had no additional value above Ct-specific IgA alone. We conclude that the new synthetic peptide-based EIA tests are able to detect species-specific antibodies, which are correlated to (active) infection, and that in particular IgA may be useful in the serodiagnosis of tubal factor infertility caused by C. trachomatis, and will contribute in simplifying the work-up in patients with infertility.

Adult↗