National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
Foodborne Pathog Dis. 2011 Jun;8(6):687-92. doi: 10.1089/fpd.2010.0739. Epub 2011 Apr 2.
One hundred two pathogenic Escherichia coli isolates from diseased pigs were analyzed for serotypes, virulence genes, antimicrobial susceptibility, and the molecular basis of phenicol resistance. Of these 102 E. coli isolates, 101 were typeable and belonged to 27 different O serogroups. However, 69% of these isolates belonged to one of the following eight serogroups: O8, O54, O64, O65, O92, O108, O119, and O120. Serogroups O8 (23%) and O64 (10%) were the most prevalent among typeable isolates. High-resistance phenotypes were observed in all the isolates, with the majority displaying resistance to chloramphenicol (89%), streptomycin (83%), enrofloxacin (78%), and doxycycline (60%). The chloramphenicol resistance genes cat1, cat2, and cmlA were detected in 58%, 49%, and 65%, respectively, of the chloramphenicol-resistant isolates. The floR gene was detected in 57% of the florfenicol-resistant isolates and in 52% of chloramphenicol-resistant isolates. Pulsed-field gel electrophoresis showed that the 32 floR-positive isolates with florfenicol minimum inhibitory concentration ≥ 8 μg mL⁻¹ belonged to 25 different pulsed-field gel electrophoresis profiles, indicating the spread of floR among swine pathogenic E. coli isolates.
从患病猪中分离出 102 株致病性大肠杆菌，对其血清型、毒力基因、抗菌药物敏感性以及氯霉素耐药性的分子基础进行了分析。这 102 株大肠杆菌中有 101 株可分型，属于 27 个不同的 O 血清群。然而，这些分离株中有 69%属于以下 8 个血清群之一：O8、O54、O64、O65、O92、O108、O119 和 O120。可分型分离株中 O8（23%）和 O64（10%）最为常见。所有分离株均表现出高度耐药表型，其中大多数对氯霉素（89%）、链霉素（83%）、恩诺沙星（78%）和强力霉素（60%）耐药。在 89%的氯霉素耐药分离株中检测到氯霉素耐药基因 cat1、cat2 和 cmlA，分别为 58%、49%和 65%。在 57%的氟苯尼考耐药分离株和 52%的氯霉素耐药分离株中检测到 floR 基因。脉冲场凝胶电泳显示，32 株氟苯尼考最小抑菌浓度≥8μg/ml 的 floR 阳性分离株属于 25 种不同的脉冲场凝胶电泳图谱，表明 floR 在猪源致病性大肠杆菌分离株中传播。
