title: Prevalence and characterization of plasmid-mediated quinolone resistance genes in extended-spectrum β-lactamase-producing Enterobacteriaceae in a Tunisian hospital.
abstract: The objective of the study was to assess the prevalence of plasmid-mediated quinolone resistance (PMQR) genes (qnrA, qnrB, qnrC, qnrD, qnrS, aac(6')-Ib-cr, qepA, and oqxAB) in a collection of 120 extended-spectrum β-lactamases (ESBLs)-producing enterobacteria and to characterize them. Overall, PMQR determinants were detected in 72 (60%) isolates (20 Escherichia coli, 32 Klebsiella pneumoniae, and 20 Enterobacter cloacae). PMQR frequencies were as follows: qnr genes (25.8%), oqxAB (21.6%), and aac(6')-Ib-cr variant (19.2%). Four qnr alleles were identified as qnrB1 (83.8%), qnrB4 (6.4%), qnrB2 (3.2%), and qnrS1 (6.4%). qnr genes were mainly detected in E. cloacae (50%), aac(6')-Ib-cr in E. coli (47.5%), and oqxAB in K. pneumoniae (65%). Overall, blaCTX-M-15 (90.3%) was the most prevalent blaESBL type followed by blaSHV-12 (6.4%) and blaSHV-27 (2.7%). Rates of mutations in gyrA and parC genes were 75% for E. coli, 72.8% for K. pneumoniae, and 50% for E. cloacae. Isolates with mutations in their quinolone resistance-determining regions exhibited high fluoroquinolones resistance levels compared to those with wild ones. Genetic study of PMQR-harboring isolates revealed a great genomic diversity among each Enterobacteriaceae species. Our findings indicate the high prevalence of PMQR determinants among ESBL-producing Enterobacteriaceae isolates from our hospital and their diffusion in various unrelated CTX-M-15-producing clones.
authors.affiliation: 1 LR99ES09 Laboratoire de Résistance aux antimicrobiens, Faculté de Médecine de Tunis, Université de Tunis El Manar , Tunis, Tunisie.
authors.forename: Sana
authors.initials: S
authors.lastname: Ferjani
authors.forename: Mabrouka
authors.initials: M
authors.lastname: Saidani
authors.forename: Faouzi Slim
authors.initials: FS
authors.lastname: Amine
authors.forename: Ilhem
authors.initials: I
authors.lastname: Boutiba-Ben Boubaker
mesh_terms: D000483:Alleles; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000235:genetics*; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000382:microbiology; D006761:Hospitals; D006801:Humans; D010957:Plasmids / Q000235:genetics*; D015995:Prevalence; D015363:Quinolones / Q000494:pharmacology*; D014416:Tunisia / Q000453:epidemiology; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D015363:Quinolones; D001618:beta-Lactamases