摘要
从6尾患肠道胀气的病鳗腹水和肝脏病灶中分离、筛选出一株致病菌EP4,通过细菌形态学、生理生化测定及ATB Expression半自动细菌鉴定仪鉴定均符合肺炎克雷伯菌(Klebsiella pneumoniae)特性。以细菌16S rRNA基因通用引物进行PCR扩增,得到EP4的部分16S rRNA基因序列,长约1 502 bp。将所测序列与GenBank中序列进行BLAST比对并构建系统进化树,结果表明其与肺炎克雷伯氏菌[DQ444287]的同源性最高(98.9%)。人工感染证明该菌株具有较强的致病力(致死率达70%),30种药物筛选结果显示,EP4对菌必治(头孢三嗪)、先锋V、头孢克洛、氧氟沙星、氟罗沙星、依诺沙星、萘啶酸等高度敏感,而对苯唑青霉素、氨苄青霉素、青霉素G、阿莫西林等不敏感。
A pathogenic bacterial strain EP4 was isolated from the ascites and liver of 6 diseased eels. The EP4 was identified as Klebsiella pneumoniae according to its morphologic and physio-biochemical characteristics as well as ATB Expression systematic identification. Using the general primers of bacteria 16S rRNA, the gene fragments were amplified by PCR with about 1 502 bp. And also, we compared the obtained gene sequence with GenBank and constructed phylogenetic tree on basis of 16S rRNA. The BLAST results showed that EP4 had the highest homologies （i. e. , 98. 9%） with sequence of K. pneumoniae DQ444287; and the phylogenetie tree results revealed further that this strain clustered together with K. pneumoniae [ DQ444287, EF197996 and EU231611]. On the other hand, the results of artificial infection experiments verified that EP4 had a strong ability of the diseases induction. By testing with 30 medicaments, high sensitivity was found to Cet riaxone, Ceph radine, Cefaclor, Ofloxaein, Fleroxaein, Enoxacin and Nalidixic acid; however, the strain of EP4 was insensitive to Oxacillin,Ampieillinum, Penicillin G and Amoxicillin.
出处
《上海海洋大学学报》
CAS
CSCD
北大核心
2009年第2期193-197,共5页
Journal of Shanghai Ocean University
基金
广东省农业领域重点项目(2008A020100016)
