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Prevalence and diversity of qnr alleles in ampc-producing enterobacter cloacae, enterobacter aerogenes, citrobacter freundii and serratia marcescens: a multicentre study from.
| Content Provider | CiteSeerX |
|---|---|
| Author | Park, Yeon-Joon Yu, Jin Kyung Lee, Seungok Oh, Eun-Jee Woo, Gun-Jo |
| Abstract | Objectives: To investigate the prevalence of qnr determinants, their influence on quinolone suscepti-bility and their association with other plasmid-mediated genes in AmpC-producing Enterobacteriaceae without any selection criteria. Methods: A total of 644 consecutive, non-duplicate isolates of Enterobacter cloacae (186), Enterobacter aerogenes (154), Citrobacter freundii (138) and Serratia marcescens (166) were examined. We performed antimicrobial susceptibility testing and PCR for qnr determinants (qnrA, qnrB and qnrS), extended-spectrum b-lactamase (ESBL) (blaTEM, blaSHV and blaCTX-M), orf513, orf1005 and blaDHA-1. To differentiate qnr subtypes, restriction enzyme analysis and sequencing was performed. Results: The prevalence of qnr determinants was high in C. freundii (38.4%) and E. cloacae (28.5%), but low in E. aerogenes (3.2%) and S. marcescens (2.4%). qnrA1 was most frequent in E. cloacae, and qnrB was prevalent in C. freundii. All the qnrA- and qnrB4-positive isolates showed ciprofloxacin MICs 0.5 mg/L and nalidixic acid MICs 16 mg/L. However, the B1 and B2 subtypes showed a wide range of quinolone MICs. In relation to ESBLs, we found that qnrA1, qnrB2 and qnrB4 producers were significantly more frequent among ESBL producers (P < 0.05). Twelve of 13 qnrB4 producers har-boured blaDHA-1. orf513 was detected in 43 isolates of the 47 isolates with co-resident qnr and ESBL |
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| Access Restriction | Open |
| Subject Keyword | Enterobacter Aerogenes Serratia Marcescens Citrobacter Freundii Qnr Allele Multicentre Study Ampc-producing Enterobacter Cloaca Qnr Determinant Qnrb4 Producer Quinolone Mics Ampc-producing Enterobacteriaceae Ciprofloxacin Mics Wide Range Qnrb4-positive Isolates Nalidixic Acid Mics Non-duplicate Isolates Qnr Subtypes Esbl Producer Antimicrobial Susceptibility Testing Quinolone Suscepti-bility Extended-spectrum B-lactamase Restriction Enzyme Analysis Plasmid-mediated Gene Enterobacter Cloaca Co-resident Qnr B2 Subtypes Selection Criterion |
| Content Type | Text |
