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First report of metronidazole resistant, nimD-positive, Bacteroides stercoris isolated from an abdominal abscess in a 70-year-old woman

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Abstract

We here present the first case of a metronidazole resistant nimD positive Bacteroides stercoris. The isolate originated from a polymicrobial intra-abdominal abscess in a 70-year-old woman. The nimD gene was detected by use of whole-genome shotgun sequencing and the subsequent use of the ResFinder 2.1 web service.

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... For example, Ank et al. described nimE together with cfiA, ermF and tetQ genes in a multidrugresistant B. fragilis isolate exhibiting piperacillin-tazobactam, carbapenem, metronidazole, clindamycin and tetracycline resistance [44]. Similarly, nimD was found in the complete genome sequence of a metronidazole-resistant Bacteroides stercoris isolate from a polymicrobial intra-abdominal abscess [74]. In the latter WGS-based studies, nim genes were mostly detected by using a database specifically designed for the identification of acquired antibiotic resistance genes in totally or partially sequenced bacterial isolates, i.e., ResFinder (http://cge.cbs.dtu.dk/services/ResFinder/) ...
... such as those linked with resistance to macrolides (erm), cefoxitin (cepA), cephalosporin (cfxA) or carbapenems (cfiA), and have been proved to be interchangeable between these genes [3,107,119]. Among all the studies recovered in the literature, the presence of an IS upstream of a nim gene is not always associated with metronidazole resistance [47,71,73,85,90,107] and, conversely, a nim gene without an upstream identified IS can be associated to metronidazole resistance [47,71,73,74,95,107,108] (Table 6). In the latter case, the resistance could be explained by another nim- independent mechanism (see part 2.2) or by the presence of a new IS not detected by the methods used. ...
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... Among the ten clinically enriched taxa, one species (Bacteroides stercoris, which can cause abdominal infections [49]), belongs to the selected target taxa that contain pathogenic bacteria. Bacteroides spp. was the only target taxa present in a high relative abundance in both hospital and nursing home wastewater (Supplementary Figure S3). ...
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