2026-05-20T04:01:56Zhttps://repisalud.isciii.es/rest/oai/request

oai:repisalud.isciii.es:20.500.12105/260322025-12-18T12:56:39Zcom_20.500.12105_2052com_20.500.12105_2051com_20.500.12105_15322col_20.500.12105_19609col_20.500.12105_16959

00925njm 22002777a 4500 dc Valdezate, Sylvia author Medina-Pascual, Maria Jose author Villalón, Pilar author Garrido, Noelia author Monzon-Fernandez, Sara author Cuesta de la Plaza, Isabel author Cobo, Fernando author 2024-07-01 Background: Bacteroides fragilis, an anaerobic gut bacterium and opportunistic pathogen, comprises two genetically divergent groups (or divisions) at the species level. Differences exist both in the core and accessory genomes and the beta-lactamase genes, with the cephalosporinase gene cepA represented only in division I and the carbapenemase gene cfiA only in division II. Methods: Multidrug resistance in a clinical B. fragilis strain was examined by whole-genome sequencing. Results: Strain CNM20200260 carried the antimicrobial resistance genes cepA, cfiA2, ant(6'), erm(F), mef(En2), est(T), tet(Q) and cat(A), along with 82-Phe mutation in gyrA (together with 47 amino acid changes in gyrA/B and parC/parE). bexA/B and other efflux pump genes were also observed. None of the detected insertion sequences was located upstream of cfiA2. The genome-based taxonomy coefficients (average nucleotide identity, DNA-DNA hybridization similarity and difference in genomic G + C%) with respect to genomes of the strains of B. fragilis division II and the novel species Bacteroides hominis (both cfiA-positive) met the criteria for CNM20200260 to belong to either species (>95%, >70% and <1%, respectively). No such similarity was seen with type strain NCTC 9343 or the representative genome FDAARGOS 1225 of B. fragilis (division I, cfiA-negative). Strain CNM20200260 harboured four out of nine Kyoto Encyclopedia of Genes and Genomes orthologues defined for division I and one of two defined for division II. Conclusions: This is the first description of the co-occurrence of cepA and cfiA in a Bacteroides strain, confirming the complexity of the taxonomy of this species. Valdezate S, Medina-Pascual MJ, Villalón P, Garrido N, Monzón S, Cuesta I, Cobo F. Co-occurrence of the cephalosporinase cepA and carbapenemase cfiA genes in a Bacteroides fragilis division II strain, an unexpected finding. J Antimicrob Chemother. 2024 Jul 1;79(7):1683-1687. 10.1093/jac/dkae166 1460-2091 0305-7453 The Journal of antimicrobial chemotherapy 38814812 https://hdl.handle.net/20.500.12105/26032 Co-occurrence of the cephalosporinase cepA and carbapenemase cfiA genes in a Bacteroides fragilis division II strain, an unexpected finding