广东省部分地区禽产品中印第安纳沙门菌的耐药性和耐药基因分子特征研究

MOLECULAR CHARACTERISTICS OF DRUG RESISTANCE GENES ON SALMONELLA INDIANA IN POULTRY PRODUCTS IN SOME AREAS OF GUANGDONG PROVINCE

为了解广东省部分地区禽产品中印第安纳沙门菌的耐药情况和耐药基因分子特征,本研究对2018年分离于广州市及佛山市禽样品中36株印第安纳沙门菌,利用琼脂稀释法检测其耐药性和采用PCR检测其耐药基因,并用脉冲场凝胶电泳对菌株进行分子分型。结果显示:对四环素的耐药性达100%,环丙沙星为55.6%,头孢噻肟为30.6%,97.2%(35/36)株表现出多重耐药性;β-内酰胺酶的质粒blaOXA-1、blaTEM、blaCTX-M-55检出率分别为47.2%、13.9%和2.8%,喹诺酮耐药决定区基因parC和gyrA突变率分别为86.1%和61.1%,在质粒中aac(6’)-Ib-cr、qnrS和qnrB检出率分别为58.3%、36.1%和11.1%;36株印第安纳沙门菌共有32种PFGE基因指纹图谱,且基因型差异较大。本研究结果表明,广东省禽产品中印第安纳沙门菌的感染源较为复杂。

To better understand molecular characteristics of drug resistance of Salmonella indiana in the livestock and poultry products in some areas of Guangdong province,36 isolates were obtained in 2018 from Guangzhou and Foshan,and their drug resistance was tested by using agar dilution method,resistance genes by PCR and molecular typing by pulsed field gel electrophoresis (PFGE).The results showed that all 36 (100%) isolates were resistant to tetracycline,20 (55.6%) isolates to ciprofloxacin and 11 (30.6%) isolates to cefotaxime.Among them,35 (97.2%) isolates showed multiple resistance.The detection of resistance genes by PCR showed the positive rates at 47.2%,13.9% and 2.8% for β-lactamase plasmids blaOXA-1,blaTEM and blaCTX-M-55,the mutation rates at 86.1% and 61.1% for quinolone resistance determining region genes parC and gyrA and positive rates at 58.3%,36.1%,and 11.1% for aac (6’)-Ib-cr,qnrS,and qnrB in the plasmids.Total 32 PFGE genotypes were identified from these 36 isolates,indicating complicated infection patterns of Salmonella indiana in these areas.