Characterization of clinical Escherichia coli isolates from China containing transferable quinolone resistance determinants

作者：Jiaqi Yang, Yue Luo, Jingyuan Li, Yue Ma, Chaoying Hu, Sun Young Jin, L. Ye, Shenghui Cui · 发表于：Journal of Antimicrobial Chemotherapy · 年份：2010 · DOI：10.1093/jac/dkp478 · 被引用次数：41 · 研究领域：Antibiotic Resistance in Bacteria、Antibiotics Pharmacokinetics and Efficacy、Pharmaceutical and Antibiotic Environmental Impacts

BACKGROUND: The categories of recognized transferable quinolone resistance determinants have been increasing sharply. The rapid horizontal transfer of these quinolone resistance genes has caused concern since they bring new dissemination possibilities for quinolone resistance. METHODS: In total, 579 clinical Escherichia coli isolates were subjected to antimicrobial susceptibility testing, screening for qnr alleles, qepA and aac-(6')-Ib-cr by PCR amplification and DNA sequence analysis. Isolates containing transferable quinolone resistance determinants were further characterized by mutation analysis in the quinolone resistance determining regions (QRDRs) of GyrA and ParC, phylogenetic typing and PFGE to determine their genetic relatedness. RESULTS: After PCR screening and sequence analysis, transferable quinolone resistance determinants were identified in 74 of 579 E. coli isolates (12.8%). The antimicrobial resistance profiles and phylogenetic groups differed between isolates containing different categories of transferable quinolone resistance determinant. Most of the isolates containing qepA alone were highly resistant to ciprofloxacin (MIC >or= 512 mg/L) and belonged to phylogenetic group D (22/25), while most of the isolates containing aac-(6')-Ib-cr alone belonged to phylogenetic group A (17/35) or D (16/35). Of 74 E. coli isolates containing transferable quinolone resistance determinants, 69 PFGE patterns and 19 clusters were identified. CONCLUSIONS: The great genetic va...