广西猪源致病性大肠杆菌对抗菌药物的耐药性变化分析

【目的】分析2007和2016年广西猪源致病性大肠杆菌对抗菌药物的耐药性差异,为兽医临床用药防治猪大肠杆菌病提供参考依据。【方法】2016年初从广西25个猪场采集腹泻仔猪的肠内容物、直肠棉拭子或肠系膜淋巴结等200份样品,分离大肠杆菌后进行致病力试验,选取103株致病性大肠杆菌用于体外药敏试验,将药敏试验结果与2007年的相关结果进行对比分析。【结果】从腹泻仔猪的体内共分离获得大肠杆菌178株,分离率为89%,其中有143株大肠杆菌可致试验小鼠死亡。与2007年相比,2016年广西猪源致病性大肠杆菌对50%的抗菌药物(9种)的敏感率上升,50%的抗菌药物的敏感率下降,上升最明显的为壮观霉素,升高34.9%,下降最明显的为氟苯尼考,降低46.9%;除头孢曲松和强力霉素的中介率与2007年相比基本无变化外,其余16种抗菌药物的中介率均降低,最明显的为头孢拉啶,降低55.2%;耐药率降低的抗菌药物只有阿米卡星、壮观霉素和强力霉素3种,降低12.3%~15.5%,耐药率升高的抗菌药物有15种,上升率为1.2%~62.1%,其中阿莫西林上升62.1%,氟苯尼考上升57.0%。耐药谱方面,2007年以5~11重耐药为主,占受试菌总数的75.7%,2016年以11重耐药以上为主,占74.8%。【结论】当前广西猪源致病性大肠杆菌以广谱耐药为主,敏感性降低,中介率降低,耐药率明显升高,生产中可选用阿米卡星和壮观霉素进行猪大肠杆菌病防治。

Antimicrobial resistance variation of pathogenic Escherichia coli isolated from pig in Guangxi

Objective]The present study determined antimicrobial resistance of pathogenic Escherichia coli isolated from pig in Guangxi in 2007 and 2016,so as to provide a foundation for the use of antimicrobials in veterinary clinical med-ication for prevention and treatment of porcine colibacillosis. Method]Two hundred samples of intestinal content, rectum cotton swab, or mesentery lymph node of diarrhea piglets were collected from twenty-five pig farms in Guangxi to isolate E. coli, pathogenicity of the isolates was detected. One hundred and three pathogenic strains were selected for in vitro an-timicrobial sensitivity test. The results were compared with those in 2007. Result]One hundred and seventy-eight E. coli strains were isolated from the samples with isolation rate of 89%, one hundred and forty-three strains of them were deadly to lab mice. In terms of drug susceptibility of pathogenic E. coli from pig, its drug susceptibility toward 50% of antimi-crobials(nine kinds) increased while the other 50%decreased in 2016 compared to 2007. The increase of drug susceptibi-lity of spectinomycin was the maximum ( 34 . 9%) while the decrease of drug susceptibility of florfenicol was the maxi-mum(46.9%). Intermediary rate of ceftriaxone and doxycycline remained stable, but intermediary rate of other 16 antimi-crobials decreased in 2006 compared to 2007. The most obvious one is cephradine, which reduced by 55.2%. The statistical results of resistance rate showed that only three kinds of antimicrobial ( amikacin , spectinomycin and doxycycline ) de-creased by 12.3%-15.5%,while the other fifteen kinds of antimicrobial increased by 1.2%-62.1%,and resistance rate of amoxicillin increased by 62.1%, resistance rate of florfenicol increased 57.0%. The results showed that, 75.7% of the strains isolated in 2007 were resistant to 5-11 kinds of antimicrobial agents, while 74.8% of the strains isolated in 2016 were resistant to 11 kinds of antimicrobial agents. Conclusion]At present, pathogenic E. coli isolated from pig in Guangxi are mainly broad spectrum resistant, drug susceptibility and intermediary rate decrease and drug resistance rate increases greatly. Amikacin and spectinomycin can be used in production for prevention and treatment of porcine colibacillosis.