Laboratory of Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan.
Department of Microbiology, Sapporo Medical University School of Medicine, Sapporo, Japan.
J Med Microbiol. 2014 Feb;63(Pt 2):263-270. doi: 10.1099/jmm.0.054676-0. Epub 2013 Feb 21.
This study aimed to investigate the genetic association between fluoroquinolone (FQ) and/or cephalosporin (CEP) resistance in Escherichia coli isolates from dogs, and the risk to human health. We characterized E. coli clinical isolates, derived from faecal samples of dogs attending veterinary hospitals, using phylogenetic grouping, determination of virulence factor (VF) prevalence, multilocus sequence typing (MLST) and O serotyping. The D group was the dominant phylogenetic group among strains resistant to FQ and/or CEP. In contrast, the dominant group among susceptible strains was group B2. Group D strains showed a significantly higher prevalence of VFs than strains belonging to groups A and B1, and were resistant to significantly more antimicrobials than group B2 strains. The phylogenetic distribution of FQ-CEP-resistant E. coli groups (FQ-CEPRECs) and FQ-resistant groups was significantly correlated (r = 0.98), but FQ-CEPRECs and CEP-resistant E. coli groups were not correlated (r = 0.58). Data from PFGE, O serotype and MLST analyses indicated that the majority of FQ-resistant strains derived from a particular lineage of phylogenetic group D: serotype O1 and sequence type (ST) 648. Some D-O1-ST648 strains carried blaCMY-2, showed multidrug resistance and possessed a higher prevalence of the VFs kspMT, ompT and PAI compared with other group D strains. Our data indicate that the emergence of FQ-CEP-resistant E. coli is based primarily on FQ-resistant E. coli. Moreover, as strains of the D-O1-ST648 lineage have been found in clinical isolates derived from humans at a relatively high frequency, our findings indicate that the spreading of D-O1-ST648 strains may cause serious difficulties in both veterinary and human clinical fields in the future.
本研究旨在探讨狗源大肠杆菌对氟喹诺酮（FQ）和/或头孢菌素（CEP）耐药的遗传相关性及其对人类健康的风险。我们通过对来自兽医医院就诊犬的粪便样本中分离出的大肠杆菌临床株进行表型分组、毒力因子（VF）流行率检测、多位点序列分型（MLST）和 O 血清型鉴定，对其进行了特征分析。FQ 和/或 CEP 耐药株中优势菌属为 D 组，而敏感株中优势菌属为 B2 组。与 A 组和 B1 组相比，D 组菌株的 VF 流行率显著更高，耐药谱也显著更宽。FQ-CEP 耐药大肠杆菌组（FQ-CEPRECs）和 FQ 耐药组的系统发育分布显著相关（r = 0.98），但 FQ-CEPRECs 与 CEP 耐药大肠杆菌组无相关性（r = 0.58）。PFGE、O 血清型和 MLST 分析结果表明，大多数 FQ 耐药株源自特定 D 组谱系：血清型 O1 和 ST648。一些 D-O1-ST648 菌株携带 blaCMY-2，表现出多重耐药性，且 kspMT、ompT 和 PAI 等 VF 的流行率高于其他 D 组菌株。本研究数据表明，FQ-CEP 耐药大肠杆菌的出现主要基于 FQ 耐药大肠杆菌。此外，由于 D-O1-ST648 株系已在源自人类的临床分离株中以较高频率发现，因此，我们的研究结果表明，D-O1-ST648 菌株的传播可能会在未来给兽医和人类临床领域带来严重的挑战。
