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Henri Verbrugh

Publications and source records attributed to Henri Verbrugh.

24 records · Page 2Linked to original sources
PubMed2002

Environmental occurrence of Madurella mycetomatis, the major agent of human eumycetoma in Sudan.

Madurella mycetomatis is the main causative agent of human eumycetoma, a severe debilitating disease endemic in Sudan. It has been suggested that eumycetoma has a soil-borne or thorn prick-mediated origin. For this reason, efforts were undertaken to culture M. mycetomatis from soil samples (n = 43) and thorn collections (n = 35) derived from areas in which it is endemic. However, ribosomal sequencing data revealed that the black fungi obtained all belonged to other fungal species. In addition, we performed PCR-mediated detection followed by restriction fragment length polymorphism (RFLP) analysis for the identification of M. mycetomatis DNA from the environmental samples as well as biopsies from patients with mycetoma. In the case of the Sudanese soil samples, 17 out of 74 (23%) samples were positive for M. mycetomatis DNA. Among the thorn collections, 1 out of 22 (5%) was positive in the PCR. All PCR RFLP patterns clearly indicated the presence of M. mycetomatis. In contrast, 15 Dutch and English control soil samples were all negative. Clinically and environmentally obtained fungal PCR products share the same PCR RFLP patterns, suggesting identity, at least at the species level. These observations support the hypothesis that eumycetoma is primarily environmentally acquired and suggest that M. mycetomatis needs special conditions for growth, as direct isolation from the environment seems to be impossible.

DNA, Fungal↗
PubMed2002

Characterization of Clostridium perfringens strains isolated from Polish patients with suspected antibiotic-associated diarrhea.

BACKGROUND: The aim of our research was to investigate the role of enterotoxin- producing anaerobic bacteria other than Clostridium difficile in the etiology of antibiotic-associated diarrhea. This article presents data related to C. perfringens. MATERIAL/METHODS: Stool samples taken from 158 patients with suspected antibiotic-associated diarrhea were specifically cultured for Clostridium difficile, Bacteroides fragilis and Clostridium perfringens. In order to associate the presence of virulence factors in the bacterial isolates thus collected with disease features, all strains were genetically and phenotypically analyzed for toxin production. All isolated C. perfringens strains were cultured in Ellner sporulation-promoting medium. RESULTS: In 21 of the 158 patients (13%) C. perfringens could be cultivated from the fecal specimen. None of the strains produced enterotoxin, and consequently the cpe gene was not detected by PCR in any of these strains. C. perfringens and C. difficile were cultivated from the same stool samples in 4 cases. Interestingly, in one case toxin A-negative/toxin B positive C. difficile and non-enterotoxigenic C. perfringens were co-cultured. After application of a heat shock (100 degrees C at 30 min.) only two C. perfringens strains producing thermoresistant spores were detected. Pulsed field gel electrophoresis (PFGE) demonstrated genetic heterogenicity among the C. perfringens strains, suggesting that these bacteria were already presented upon hospital admission. CONCLUSIONS: It seems unlikely that nosocomial transfer has taken place. The relatively low incidence suggests that C. perfringens is not a major primary cause of antibiotic-associated diarrhea.

Anti-Bacterial Agents↗
PubMed1997

PCR ribotyping and arbitrarily primed PCR for the comparison of enterotoxigenic Bacteroides fragilis strains from two Polish university hospitals.

OBJECTIVE: To study the clinical incidence and possible clonal relatedness of enterotoxigenic strains of Bacteroides fragilis among pediatric and adult patients in two Polish university hospitals. METHODS: Fecal samples from 201 adults and 131 infants (with or without diarrhea) and vaginal samples from 100 pregnant women nursed in two Polish university hospitals were analyzed with respect to carriage of enterotoxin-producing Bacteroides fragilis (ETBF). This putative pathogen was identified by cultivation and subsequent cytopathogenicity testing of culture supernatants on HT/29 C1 cells. RESULTS AND DISCUSSION: Two ETBF strains were isolated from childrens' feces; two additional strains were isolated from adults, and from the vaginal samples only a single strain was isolated. One strain (W2) was isolated from a child with diarrhea. These incidence figures, the fact that all ETBF isolates were shown to produce strongly differing amounts of the cytotoxin, and the genetic unrelatedness of the strains as demonstrated by two different PCR-mediated DNA typing procedures, indicates that clonal spread of ETBF is presently not a clinical problem in these hospitals. It was shown that PCR-mediated ribotyping and arbitrarily primed PCR can be applied with success to study the epidemiology of ETBF.

Journal Article↗
PubMed1997

Two clones of methicillin-resistant Staphylococcus aureus in Poland.

OBJECTIVE: To evaluate relatedness among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated in Poland. METHODS: Ninety-three MRSA hospital isolates were collected from different regions in Poland from 1990 to 1992. Strains were analyzed with respect to heterogeneity of methicillin resistance, phage types, resistance patterns, crystal violet staining, chromosomal DNA SmaI restriction patterns by PFGE, ERIC1 and ERIC2 AP-PCR types and DNA repeat polymorphism within the protein A gene. Resistance to methicillin was confirmed by the detection of the mecA gene by PCR. RESULTS: The combined results of typing methods demonstrate that all MRSA strains analyzed could be easily divided into two distinct clones (clonally related strains). The first consisted of strains with clear heterogeneous expression of resistance to methicillin (34 isolates) and the second showed more homogeneous resistance (59 isolates). In this study the best method for epidemiologic analysis of MRSA was found to be PFGE. A good correlation between the epidemic behavior of MRSA and a high number of repetitive DNA units within the protein A gene was observed. CONCLUSIONS: Results show that in Poland two distinct clones of epidemic MRSA have circulated in the past, easily discriminated by pheno- and genotyping methods, and both could be found together in a single hospital.

Journal Article↗
PubMed1996

Typing of Pseudomonas aeruginosa strains from patients with cystic fibrosis: phenotyping versus genotyping.

OBJECTIVE: To assess the discriminatory power of two genotypic and two phenotypic techniques by analysis of Pseudomonas aeruginosa sputum isolates obtained with long term intervals from 29 independent cystic fibrosis (CF) patients. METHODS: Fifty-eight strains of P. aeruginosa were subjected to serotyping and pyocin production was assessed. Arbitrarily primed polymerase chain reaction (AP PCR) and pulsed-field gel electrophoresis (PFGE) were applied in order to detect genetic polymorphisms. RESULTS: From the results of different typing techniques, it appeared that the numbers of separate types varied between 11 and 43, and the percentage of identical P. aeruginosa pairs from individual patients varied between 51% and 72%, depending on the test system used. AP PCR and PFGE displayed enhanced resolution when compared to serotyping and pyocin typing; both DNA typing techniques generated concordant results, although differences in resolution are apparent. This results in 15% discordance, which may be the result of differences in the definitions of (sub)clonal relatedness as applied for AP PCR and PFGE, respectively. CONCLUSIONS: Molecular typing techniques are superior to phenotyping where P. aeruginosa is concerned. AP PCR is a fast and useful technique for determining clonality among P. aeruginosa strains from chronically colonized CF patients. It is clear, however, that the interpretation of data and comparative analysis of PFGE and AP PCR results necessitates additional (international) standardization and the development of practical guidelines.

Journal Article↗