Dynamics of Quinolone Resistance in Fecal Escherichia coliof Finishing Pigs after Ciprofloxacin Administration

Journal of Veterinary Medical Science

Hong-Ning WANG¹  Kang HUANG¹  An-Yun ZHANG¹  Bo ZENG¹  Han CHENG¹  Qing-Qing XIA¹  Chang-Wei LEI¹  Chang-Wen XU¹  Zhong-Bin GUAN¹ 

[1] School of Life Science, Sichuan University, Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, �?985 Project�? Science Innovative Platform for Resource and Environment Protection of Southwestern China, Chengdu, Sichuan 610064, P. R. China

关键词: ciprofloxacin;    dynamics;    Escherichia coli;    quinolone resistance;    swine;   

DOI  :  10.1292/jvms.14-0025

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

References(34)Escherichiacoli resistance to quinolones has now become a serious issue in large-scale pigfarms of China. It is necessary to study the dynamics of quinolone resistance in fecalEscherichia coli of pigs after antimicrobial administration. Here, wepresent the hypothesis that the emergence of resistance in pigs requires drug accumulationfor 7 days or more. To test this hypothesis, 26 pigs (90 days old, about 30 kg) not fedany antimicrobial after weaning were selected and divided into 2 equal groups: theexperimental (EP) group and control (CP) group. Pigs in the EP group were orally treateddaily with 5 mg ciprofloxacin/kg of body weight for 30 days, and pigs in the CP group werefed a normal diet. Fresh feces were collected at 16 time points from day 0 to day 61. Ateach time point, ten E. coli clones were tested for susceptibility toquinolones and mutations of gyrA and parC. The resultsshowed that the minimal inhibitory concentration (MIC) for ciprofloxacin increased 16-foldcompared with the initial MIC (0.5 µg/ml) afterciprofloxacin administration for 3 days and decreased 256-fold compared with the initialMIC (0.5 µg/ml) after ciprofloxacin withdrawal for 26days. GyrA (S83L, D87N/ D87Y) and parC (S80I)substitutions were observed in all quinolone-resistant E. coli (QREC)clones with an MIC �?8 µg/ml. This study providesscientific theoretical guidance for the rational use of antimicrobials and the control ofbacterial resistance.

【 授权许可】

Unknown