Vaginal carriage of enterotoxigenic Bacteroides fragilis in pregnant women

Abstract

Bacteroides fragilis is an anaerobic bacterial species that is involved in gynecological infections and pathology. The incidence of vaginal carriage is largely unknown, and in order to study this, 120 pregnant women attending a general hospital for delivery were examined. Cultures were positive for eight of these women (6.6%). Interestingly, potential clonal relatedness could be demonstrated among several of the nonenterotoxigenic B. fragilis strains. Among the strains, only one produced metalloprotease enterotoxin. The presence of the gene for the metalloprotease, giving rise to the pathogenic effect on cultured eukaryotic HT29/C1 cells, was confirmed by a newly designed specific PCR assay. The enterotoxigenic B. fragilis (ETBF) strain was analyzed with the help of arbitrarily primed PCR (AP-PCR) and PCR-mediated ribotyping. The ETBF strain was shown to be genetically different compared to several other strains obtained from diverse sources. Our data indicate a relatively high vaginal B. fragilis carriage rate among pregnant women in Warsaw, Poland. Although neither ETBF nor B. fragilis colonization presented a clinical problem, the possible genetic relatedness among the colonizing B. fragilis strains indicates the need for additional research in the field of ETBF transmission and molecular epidemiology.

Bacteroides and Hafnia Infections Associated With Chorioamnionitis and Preterm Birth

“…The bacterium has been associated with intra-amniotic infections [9], spontaneous mid-gestation abortion and PROM [10]. Nonetheless, a relatively high carriage rate of B. fragilis, including enterotoxigenic strains, without presenting clinical problems was reported amongst pregnant women in Poland [11]. The impact of vaginal colonization by enterotoxigenic B. fragilis and the full spectrum clinical diseases related to it remain to be defined [12].…”

Genetic Variation in 16S‐23S rDNA Internal Transcribed Spacer Regions and the Possible Use of This Genetic Variation for Molecular Diagnosis of Bacteroides Species

“…These findings suggest that ITS-based classification of B. fragilis could be widely applied and that more ITS amplification types could be observed if we were to perform tests using a large number of strains. Leszczynski et al studied the correlation between several molecular typing and biological features of B. fragilis, such as enterotoxigenicity and antimicrobial properties, but they could not find a significant relationship between ITS-based subtyping and enterotoxigenicity of B. fragilis (22). Further analysis is expected to determine whether the ITS-based epidemiological typing correlates with some biological characteristics of B. fragilis.…”

An archival case of clinically significant infection in a surgical patient by enterotoxigenic Bacteroides fragilis: PCR amplification of the metalloprotease enterotoxin gene from non-viable lyophilizates

“…In addition, the enterotoxin was found to be a metalloprotease, the gene for which has been sequenced on two separate occasions [6,7]. Consequently, diagnostic PCR assays could be developed [8,9] and, moreover, the two sequence types can be discriminated on the basis of restriction fragment length polymorphism (RFLP) analysis (Leszczynski et al, unpublished observations).…”