体外诱导禽巴氏杆菌环丙沙星耐药株及耐药机制的初步分析  

Characterization of ciprofloxacin-resistant avian Pasteurella multocida via in-vitro induction and preliminary analysis of resistance mechanism

作　　者：孔令严[1,2] 李槿年[2] 卢琴[1] 邵华斌[1] 罗青平[1] 

机构地区：[1]湖北省农业科学院畜牧兽医研究所,武汉430064 [2]安徽农业大学动物科技学院,合肥230036

出　　处：《黑龙江畜牧兽医》2017年第8期166-169,共4页Heilongjiang Animal Science And veterinary Medicine

基　　金：公益性农业行业科研专项(201303044);现代农业产业技术体系建设专项(CARS-42-G11);规模化养鸡场主要疫病防控关键技术研究项目(2015ABA039)

摘　　要：为了探讨在环丙沙星(ciprofloxacin,CIP)药物培养后,多杀性巴氏杆菌(Pasteurella multocida,Pm)对CIP的药物敏感性变化及其耐药机制,试验采用体外递增药物浓度的方法诱导出禽源Pm标准株C48-1对CIP的耐药菌株,并对CIP耐药菌株的最小抑菌浓度(MIC)值变化及耐药稳定性、生化特性、生长曲线和基因组位点突变进行了研究。结果表明:诱导的CIP耐药菌株的MIC由0.25μg/mL上升至16μg/mL;与亲本株比较,生化特性与生长曲线无显著差异,但诱导株的喹诺酮类耐药决定区(QRDR)gyrA基因编码的氨基酸发生了Thr99→Ala的变化,该位点突变首次发现,gyrB、parC、parE耐药基因均未发生变化。说明逐步递增药物浓度可以诱导禽源Pm对氟喹诺酮类药物的耐药性,并导致靶基因发生突变。To investigate the drug susceptibility variety of avian Pasteurella multocida （Pm）in the culture with ciprofloxacin（CIP） and its mecha- nism,in this experiment a CIP - resistant avian Pm was obtained via in - vitro induction with increasing drug concentrations to the standard strain named C48 - 1. The minimal inhibitory concentration（ MIC ）, stability of drug resistance, biochemical characteristics, growth curve and ge- nome site mutation of the CIP - resistant strain was analyzed. The results showed that the MIC of the CIP - resistant strain was increasing from 0.25 μg/mL to 16 μg/mL. Compared with the parent strain, the biochemical characteristics and growth curve had no significant difference. However, the amino acid sequence encoded by the gyrA gene located in Quinolone resistance - determining region（QRDR） of the CIP - resistant strain had an amino acid exchange of Th199→Ala. It was the first time that the site mutation was found. There was no change in resistance genes gyrB, parC or parE. The results suggested that the increasing drug concentration could induce avian Pm to acquire the resistance to fluore- quinolones and lead to mutations of target genes.

关 键 词：禽源多杀性巴氏杆菌 体外诱导 环丙沙星 耐药决定区 位点突变 耐药机制 

分 类 号：S852.61[农业科学—基础兽医学] S859[农业科学—兽医学]