Prevalence and genetic analysis of plasmid-mediated quinolone resistance determinants QnrA and QnrS in Enterobacteriaceae isolates from a French university hospital.
The spread of plasmid-mediated quinolone resistance determinants QnrA and QnrS was evaluated in a collection of 186 extended-spectrum beta-lactamase (ESBL)-positive enterobacterial isolates from 2002 to 2005 and 185 nalidixic acid-resistant strains isolated during the first 6 months of 2005 at the Bicêtre hospital, France. Out of these 186 ESBL-positive isolates, 2.2 and 1.6% carried a QnrA1 and a QnrS1 determinant, respectively. The ESBLs associated with QnrA1 were VEB-1, SHV-12, and CTX-M-1, whereas those associated with QnrS1 were TEM-52, SHV-12, and CTX-M-1. Among the 185 nalidixic acid-resistant strains isolated in 2005, 0.5 and 2.7% had a QnrA1 determinant and a QnrS1 determinant, respectively. The genetic environments of the qnrA1 gene differed but were always associated with sul1 type integrons. In contrast, qnrS1 genes were not embedded in class 1 integrons but located often (but not systematically) downstream of the insertion sequence ISEcl2 on plasmids that often carried a novel beta-lactamase gene, bla(LAP-1). This is the first study identifying the QnrS resistance determinant in Europe and indicating that this determinant might also be widespread.
Poirel
Laurent
L
Service de Bactériologie-Virologie, Hôpital de Bicêtre, Faculté de Médecine Paris-Sud, Université Paris XI, 94275 Le Kremlin-Bicêtre cedex, France.
Leviandier
Cécile
C
Nordmann
Patrice
P
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003001:Cloning, Molecular; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D018274:Electroporation; D004755:Enterobacteriaceae / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D005602:France / Q000453:epidemiology; D005798:Genes, Bacterial; D006785:Hospitals, University / Q000706:statistics & numerical data; D032023:Integrons; D008826:Microbial Sensitivity Tests; D009693:Nucleic Acid Hybridization; D010957:Plasmids / Q000032:analysis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D015995:Prevalence; D015363:Quinolones / Q000494:pharmacology*; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D015363:Quinolones; D001618:beta-Lactamases