RESUMEN
In this study, 922 consecutive non-duplicate clinical isolates of Enterobacteriaceae obtained from hospitalized and non-hospitalized patients at Bejaia, Algeria were analyzed for AmpC-type β-lactamases production. The ampC genes and their genetic environment were characterized using polymerase chain reaction (PCR) and sequencing. Plasmid incompatibility groups were determined by using PCR-based replicon typing. Phylogenetic grouping and multilocus sequence typing were determined for molecular typing of the plasmid-mediated AmpC (pAmpC) isolates.Of the isolates, 15 (1.6%) were identified as AmpC producers including 14 CMY-4- producing isolates and one DHA-1-producing Klebsiella pneumoniae. All AmpC-producing isolates co-expressed the broad-spectrum TEM-1 β-lactamase and three of them co-produced CTX-M and/or SHV-12 ESBL. Phylogenetic grouping and virulence genotyping of the E. coli isolates revealed that most of them belonged to groups D and B1. Multilocus sequence typing analysis of K. pneumoniae isolates identified four different sequence types (STs) with two new sequences: ST1617 and ST1618. Plasmid replicon typing indicates that bla CMY-4 gene was located on broad host range A/C plasmid, while LVPK replicon was associated with bla DHA-1. All isolates carrying bla CMY-4 displayed the transposon-like structures ISEcp1/AISEcp1-blaCMY-blc-sugE. Our study showed that CMY-4 was the main pAmpC in the Enterobacteriaceae isolates inAlgeria.
Asunto(s)
Humanos , Antibacterianos/farmacología , Cefoxitina/farmacología , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/genética , Klebsiella pneumoniae/genética , Argelia , Resistencia betalactámica , Proteínas Bacterianas/genética , ADN Bacteriano/genética , Enterobacteriaceae/aislamiento & purificación , Genotipo , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , beta-Lactamasas/genéticaRESUMEN
OBJECTIVE@#To investigate the mechanisms of quinolone resistance and the association with other resistance markers among Esherichia coli (E. coli) strains isolated from outpatient with urinary tract infection in north of Algeria.@*METHODS@#A total of 30 nalidixic acid-resistant E. coli isolates from outpatient with urinary tract infections from January 2010 to April 2011 in north of Algeria (Bejaia) were studied. Antimicrobial susceptibility was determined by disc diffusion assay, minimal inhibitory concentrations (MIC) of quinolone were determined by microdilution. Mutations in the Quinolone Resistance-Determining Region (QRDR) of gyrA and parC genes and screening for qnr (A, B and S) and bla genes were done by PCR and DNA sequencing.@*RESULTS@#Most of the E. coli isolates (56.66%) were shown to carry mutations in gyrA and parC (gyrA: Ser83Leu + Asp87Asn and parC:Ser80Ile). While, 16.66% had only an alteration in gyrA: Ser83Leu. One isolate produced qnrB-like and two qnrS-like. Four isolates were CTX-M-15 producers associated with TEM-1 producing in one case. Co-expression of blaCTX-M-15 and qnrB was determined in one E. coli isolate.@*CONCLUSIONS@#Our findings suggested the community emergence of gyrA and parC alterations and Qnr determinants that contributed to the development and spread of fluoroquinolone resistance in Algerian E. coli isolates.