摘要
目的对市场采集的零售猪肉样品进行环丙沙星与头孢噻肟双耐药大肠杆菌检测和耐药机制分析。方法从陕西汉中(n=81)和北京(n=37)采集新鲜零售猪肉样品,对环丙沙星与头孢噻肟双耐药大肠杆菌进行分离、药敏和耐药机制分析。结果 22.0%(26/118)的零售猪肉样品检出环丙沙星与头孢噻肟双耐药大肠杆菌,以系统发生A群为主(12株),优势耐药谱型为AMP-CAZ-CTX-CIP-CHL-GEN-SXT-TET(n=14)和AMP-CAZ-CTXCIP-CHL-SXT-TET(n=7),所有菌株的拓扑异构酶喹诺酮耐药决定区中均有点突变,从12个菌株中检出质粒介导喹诺酮耐药机制;从24株产超广谱β-内酰胺酶大肠杆菌中共检出4个blaCTX-M型,其中blaCTX-M-55(n=22)为优势型。结论社区零售猪肉是环丙沙星与头孢噻肟双耐药大肠杆菌的重要储存库,其中blaCTX-M-55为三代头孢耐药的主要机制。
Objective To investigate the prevalence and characteristics of cefotaxime and ciprofloxacin co-resistant Escherichia coli（E.coli） isolates in retail pork samples.Methods Retail pork samples were collected from 12 supermarkets and 7 farmer＇s markets in Beijing（n = 37） and Hanzhong（n = 81）;cefotaxime and ciprofloxacin co-resistant E.coli isolates were recovered and subjected to antimicrobial susceptibility testing and resistant mechanism analysis.Results Cefotaxime and ciprofloxacin co-resistant E.coli isolates were recovered in 22.0%（26 /118） of retail pork samples.E.coli isolates of phylogenetic group A were dominant（12 isolates）.The dominant resistant profiles were ampicillin（AMP）-ceftazidime（CAZ）-cefotaxime（CTX）-ciprofloxacin（CIP）-chloramphenicol（CHL）-gentamicin（GEN）-trimethoprim-sulfamethoxazole（SXT）-tetracycline（TET）（n = 14） and AMP-CAZ-CTX-CIP-CHL-SXT-TET（n = 7）.Point mutations in quinolone resistance determination regions of topoisomerases were identified in all the isolates.Plasmid mediated quinolone resistant determinants were identified in 12 isolates.Four subtypes of blaCTX-Mwere identified in 24 extended spectrum β-lactamases producing E.coli isolates and blaCTX-M-55（n =22）was dominant.Conclusion This study highlights that retail pork could serve as an important reservoir of cefotaxime and ciprofloxacin co-resistant E.coli.The dominant β-lactam resistant mechanism is blaCTX-M-55（n =22）.
出处
《中国公共卫生》
CAS
CSCD
北大核心
2014年第10期1363-1364,共2页
Chinese Journal of Public Health
基金
科技部国家高技术研究发展计划(2012AA101003)
关键词
大肠杆菌
环丙沙星
头孢噻肟
耐药
猪肉
Escherichia coli
cefotaxime
ciprofloxacin
drug resistance
pork
