title: Plasmid-mediated quinolone resistance in Australia.
abstract: The aim of this study was to search for plasmid-encoded quinolone resistance determinants QnrA and QnrS in fluoroquinolone-resistant and extended-spectrum beta-lactamase (ESBL)-producing enterobacterial isolates recovered in Sydney, Australia, in 2002. Twenty-three fluoroquinolone-resistant, of which 16 were also ESBL-positive, enterobacterial and nonrelated isolates were studied. PCR with primers specific for qnrA and qnrS genes and primers specific for a series of ESBL genes were used. A qnrA gene was identified in two ESBL-positive isolates, whereas no qnrS-positive strain was found. The QnrA1 determinant was identified in an Enterobacter cloacae isolate and in a carbapenem-resistant Klebsiella pneumoniae isolate, both of which expressed the same ESBL SHV- 12. Whereas no plasmid was identified in the E. cloacae isolate, K. pneumoniae K149 possessed two conjugative plasmids, one that harbored the qnrA and bla (SHV)-12 genes whereas the other expressed the carbapenemase gene bla (IMP-4). The qnrA gene, was located in both cases downstream of the orf513 recombinase gene and upstream of the qnrA1 gene, a structure identical to that found in sul1-type integron In36 and qnrA-positive strains from Shanghai, China. However, the gene cassettes of the sul1-type integrons were different. This study identified the first plasmid-mediated quinolone resistance determinant in Enterobacteriaceae in Australia.
authors.affiliation: Service de Bactériologie-Virologie, Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, Faculté de Médecine Paris-Sud, Université Paris XI, K.-Bicêtre, France.
authors.forename: Jose-Manuel
authors.initials: JM
authors.lastname: Rodriguez-Martinez
authors.forename: Laurent
authors.initials: L
authors.lastname: Poirel
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pascual
authors.forename: Patrice
authors.initials: P
authors.lastname: Nordmann
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001315:Australia / Q000453:epidemiology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016972:Enterobacter cloacae / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D024841:Fluoroquinolones / Q000494:pharmacology*; D005798:Genes, Bacterial; D006801:Humans; D007711:Klebsiella pneumoniae / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011815:R Factors; D001618:beta-Lactamases / Q000096:biosynthesis
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D001618:beta-Lactamases