淡水鱼产气荚膜梭菌的分离及毒素型的鉴定  

Isolation and Identification of Toxin Types of Clostridium perfringens from Freshwater Fishes

作　　者：蔡玉梅[1] 柴同杰[1] 蔡春梅 段会勇[1] 姜世金[1] 

机构地区：[1]山东农业大学动物科技学院,泰安271018 [2]德州市肿瘤医院,德州253000

出　　处：《农业生物技术学报》2009年第3期476-481,共6页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金专项基金项目(No.30571381)资助

摘　　要：为研究产气荚膜梭菌(Clostridium perfringens)在淡水鱼中的分布及毒素型,随机采取同一水库的鲤鱼(Cyprinus car-pio)、鲢鱼(Hypophthalmichthys molitrix)、鲫鱼(Carassius auratus)、鲶鱼(Silurus asotus)和黄鳝(Monopterus albus)淡水鱼样品420尾,用细菌学方法分离肠内容物中的产气荚膜梭菌,PCR方法检测分离菌株的α、β、ε、ι、β2和肠毒素基因以及肠内容物产气荚膜梭菌阳性的鱼肉组织中的α毒素基因,PCR扩增片段克隆后进行核苷酸序列分析并且与GenBank相应毒素基因进行同源性比较。结果表明,自75份肠内容物样品中分离出产气荚膜梭菌,59株为C型,12株为A型,4株为B型;三型菌株均能扩增出β2条带,A、C型菌株均检出肠毒素基因;检出基因与GenBank相应基因的同源性在98%以上,鱼肉中毒素基因检测结果为阴性。在淡水鱼检出产气荚膜梭菌的α、β、ε、β2和肠毒素基因,在B型产气荚膜梭菌中扩增出β2毒素基因均属首次。To study the isolation rate and toxin type of Clostridium perfringens from freshwarter fishes, 420 flesh intestinal content samples （not including intestinal tissues） of freshwater fishes （Hypophthalmichthys molitrix, Cyprinus carpio, Carassius auratus,Monopterus albus and Silurus asotus） caught from the same water reservoir were examined by bacteriological method for the occurrence of C. perfringens. Genes encoding alpha, beta, epsilon, iota, beta2 and enterotoxin from the isolates were examined by PCR for toxin type classification. These amplified toxin gene fragment were cloned and sequenced and compared with the corresponding genes in GenBank to reveal the homology. Then, alpha toxin gene detected from fish muscle （C. perfringens positive in intestinal content） was performed for food safety assessing. Results showed that C. perfringens could be isolated in 75 intestinal content samples （17.9%） from freshwater fish, 59 strains were toxin type C （alpha and beta toxin positive）, 12 strains were toxin type A （alpha toxin positive） and 4 strains were toxin type B （alpha,beta and epsilon toxin positive）. In addition, the gene encoding for beta2 and enterotoxin were found in type C and type A isolates, beta2 toxin was also detected from type B strains. But, toxin gene was negative in fish muscle.The homology between the detecting toxin genes and the corresponding reference exceeded 98%. This is the first report of C. perfingens alpha, beta, epsilon and beta2 toxins in freshwater fish, and beta and epsilon toxins in fish, and is the first discovery that the β2 toxin could be detected in strains of type B.

关 键 词：淡水鱼 产气荚膜梭菌 毒素型 核苷酸序列 

分 类 号：S188[农业科学—农业基础科学]