4 research outputs found

    A sequence database analysis of 5-nitroimidazole reductase and related proteins to expand knowledge on enzymes responsible for metronidazole inactivation

    No full text
    International audiencenim genes are associated, in combination with other factors, with acquired resistance to metronidazole (MTZ) in anaerobes. These genes encode 5-nitroimidazole reductase enzymes (Nim proteins) that reduce MTZ into an inactive compound. Eleven variants (nimA to nimK) are currently described in anaerobes with either a chromosomal or a plasmidic location. Mostly found in members of the Bacteroides fragilis group, nim genes were demonstrated in anaerobic taxa outside the phylum Bacteroidetes. Nitroreductase enzymes, weakly related to those found in Bacteroidetes but associated with MTZ inactivation, were also characterized both in anaerobic and non-anaerobic taxa. Published data only poorly reflect the growing number of data from cultivation-independent studies and sequences deposited in databases. Considering this limitation, we performed herein an analysis of the sequence databases with the aim to increase the current knowledge on Nim protein distribution and diversity. The 250 sequences the most closely related to the 11 known Nim proteins were selected and analyzed for identity level and phylogenetic relationships with Nim A to K proteins. The analysis revealed a larger diversity of anaerobic species harboring known Nim proteins than that currently described in the literature. Putative new variants of known Nim proteins and novel Nim proteins were found. In addition, nitroreductase proteins and homologs related to the pyridoxamine 5'-phosphate oxidase family were found in highly diverse anaerobic and aerobic taxa of human but also animal and environmental origin. On the other hand, we found a very low number of sequences recovered from metagenomic studies. Considering the different databases currently available to identify antimicrobial resistance genes (ARG) among metagenomic sequences, we hypothesized that this may, at least in part, be related to the incompleteness of ARG databases because none of them includes the 11 described nim genes at the time of our study. Both the wide distribution of proteins with potential MTZ inactivation ability within the bacterial world and a wider diversity of Nim determinants than expected from published literature is underlined in this sequence database analysis

    A New Look at the Genus Solobacterium: A Retrospective Analysis of Twenty-Seven Cases of Infection Involving S. moorei and a Review of Sequence Databases and the Literature

    No full text
    International audienceSolobacterium moorei is an anaerobic Gram-positive bacillus present within the oral and the intestinal microbiota that has rarely been described in human infections. Besides its role in halitosis and oral infections, S. moorei is considered to be an opportunistic pathogen causing mainly bloodstream and surgical wound infections. We performed a retrospective study of 27 cases of infections involving S. moorei in two French university hospitals between 2006 and 2021 with the aim of increasing our knowledge of this unrecognized opportunistic pathogen. We also reviewed all the data available in the literature and in genetic and metagenomic sequence databases. In addition to previously reported infections, S. moorei had been isolated from various sites and involved in intra-abdominal, osteoarticular, and cerebral infections more rarely or not previously reported. Although mostly involved in polymicrobial infections, in seven cases, it was the only pathogen recovered. Not included in all mass spectrometry databases, its identification can require 16S rRNA gene sequencing. High susceptibility to antibiotics (apart from rifampicin, moxifloxacin, and clindamycin; 91.3%, 11.8%, and 4.3% of resistant strains, respectively) has been noted. Our global search strategy revealed S. moorei to be human-associated, widely distributed in the human microbiota, including the vaginal and skin microbiota, which may be other sources for infection in addition to the oral and gut microbiota
    corecore