浴场海水中大肠杆菌耐药性及其耐药基因研究

为了解海水浴场中大肠杆菌耐药性状况及其耐药基因分布,以大连星海浴场近岸海水样品为研究对象,分离鉴定得到41株大肠杆菌,采用K-B药敏纸片法检测其对9种常用抗生素的耐药性,并对耐药菌株中的耐药基因进行检测。结果表明:41株受试大肠杆菌菌株对四环素的耐药率最高(46%),而对氨曲南的耐药率最低(5%),大肠杆菌的多重耐药率达到34%。采用PCR方法对41株分离菌株进行四环素耐药基因检测,结果显示,仅四环素耐药基因tetA和tetB被检出,其他4种类型四环素耐药基因未被检出。大肠杆菌基因组与质粒DNA中tetA的检出率分别为34%和29%;tetB的检出率分别为2%和12%。相关性分析结果表明大肠杆菌的四环素耐药表型与四环素耐药基因的阳性检出率显著相关。

Study on antibiotic resistance and resistant related genes of Escherichia coli from seawater of bathing beach

To study antibiotic resistance pattern and resistant gene of Escherichia coli from seawater recreational beach,41E.coli isolates from seawater in Dalian Xinghai bathing beach were identified and characterized using biochemical tests. Antimicrobial resistance of E.coli isolates was determined by Kirby-Bauer disk diffusion method,the result showed highest resistance to tetracycline(46%) and lowest resistance against ammonia QuNa(5%). Multidrug resistance was observed in 34% of 41E.coli isolates. Only tetracycline resistant gene tetA and tetB gene were detected among the 41 isolates using PCR method. The detection frequency of tetA gene was 34% in genome DNA and 29% in plasmid DNA of E.coli. While tetB gene was detected in 2% of E.coli genome DNA and in 12% of E.coli plasmid DNA. χ2test suggest that tetracycline resistant phenotype of E.coli is correlated with tetracycline resistant gene.