宁波-舟山港口航道水域致病性细菌的毒力基因型鉴定

Virulence genetic studies of pathogenic bacteria in Ningbo-Zhoushan port and channel waters

根据标准对宁波-舟山港口航道致病性细菌进行分离,结合16S r DNA等方法鉴定分离菌株,研究其生理生化特征,通过PCR方法判断其毒力基因型,分析危害风险.结果表明,4个样品采集区的样品经分离鉴定,菌种分别为埃希氏大肠杆菌(Escherichia coli)、沙门氏菌(Salmonella sp.)、粪肠球菌(Enterococcus faecalis)、李斯特菌(Listeria monocytogenes)、副溶血弧菌(Vibrio parahaemolyticus)、阴沟肠杆菌(Enterobacter cloacae)、溶藻弧菌(Vibrio alginolyticus)、迟缓爱德华菌(Edwardsiella tarda)、嗜水气单胞菌(Aeromonas hydrophila)等9种,其中粪肠球菌分离率最高.各种细菌的生理生化及形态特征与已报道陆源细菌相近,携带毒力基因型多样性丰富,提示具备致病力.运行Blast程序对所有分离株16S r DNA序列进行比对,发现与已知序列相似度均在98%以上.研究结果对海洋微生物的毒力基因多样性研究以及危害风险评估提供了基础.

Pathogenic bacteria from Ningbo-Zhoushan port and channel waters were isolated and identified with methods of molecular biology of 16 S r DNA PCR and morphology. Besides,physicochemical properties,virulence gene types and the harm risk caused by these bacteria were studied. The results showed that,in 4 sampling areas,the identified bacteria were Escherichia coli,Salmonella sp.,Enterococcus faecalis,Listeria monocytogenes,Vibrio parahaemolyticus,Enterobacter cloacae,Vibrio alginolyticus,Edwardsiella tarda and Aeromonas hydrophila,among them Enterococcus faecalis had the highest isolate rate. Physicochemical properties of isolated bacteria were much similar to the reported terrestrial bacteria. There were many types of virulence genes in the isolated bacteria. The study by blast program on all 16 S r DNA sequence found that the known sequences had similarities higher than98%. The results can be taken for further studies of marine virulent gene diversity and for hazard risk evaluation.