title: Plasmid-mediated quinolone resistance genes, aac(6')-Ib-cr, qnrS, qnrB, and qnrA, in urinary isolates of Escherichia coli and Klebsiella pneumoniae at a teaching hospital, Thailand.
abstract: A total of 121 Escherichia coli (47 extended-spectrum β-lactamase [ESBL] and 74 non-ESBL producers) and 75 Klebsiella pneumoniae isolates (49 ESBL and 26 non-ESBL producers) were collected from urine samples between October 2010 and April 2011 at a university hospital and assessed for the presence of plasmid-mediated quinolone resistance (PMQR) genes. Twenty-seven E. coli (22.3%) and 49 K. pneumoniae (65.3%) isolates harbored PMQR genes, which mostly consisted of aac(6')-Ib-cr and qnrS, followed by qnrB and qnrA. Among the 76 PMQR-positive isolates, 15 (19.7%) and 2 (2.6%) carried 2 and 3 different PMQR genes, respectively. However, qnrC, qnrD, and qepA were not found in any isolate. The PMQR genes were more prevalent in ESBL producers than in non-ESBL producers (42.6% versus 9.5% in E. coli and 81.6% versus 34.6% in K. pneumoniae). Approximately 35%-60% of the PMQR-positive isolates were susceptible or intermediately susceptible to fluoroquinolones. The enterobacterial repetitive intergenic consensus-PCR method revealed that most PMQR-positive isolates belonged to different strains, indicating the spread of these resistance determinants. PMQR gene transfer by conjugation was successful in 10%-25% of the test donors. This study showed a high prevalence of PMQR genes among both organisms. Clinical use of fluoroquinolones for the treatment of infections caused by fluoroquinolone-susceptible strains harboring PMQR genes may lead to decreased therapeutic efficacy.
authors.affiliation: Graduate School, Khon Kaen University.
authors.forename: Woravit
authors.initials: W
authors.lastname: Pasom
authors.forename: Aroonwadee
authors.initials: A
authors.lastname: Chanawong
authors.forename: Aroonlug
authors.initials: A
authors.lastname: Lulitanond
authors.forename: Chotechana
authors.initials: C
authors.lastname: Wilailuckana
authors.forename: Suthida
authors.initials: S
authors.lastname: Kenprom
authors.forename: Pirom
authors.initials: P
authors.lastname: Puang-Ngern
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003227:Conjugation, Genetic; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D006784:Hospitals, Teaching; D006801:Humans; D007711:Klebsiella pneumoniae / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D058889:Molecular Typing; D010957:Plasmids; D015363:Quinolones / Q000494:pharmacology*; D013785:Thailand; D014552:Urinary Tract Infections / Q000382:microbiology; D014556:Urine / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D015363:Quinolones