摘要
为鉴定一株引起草鱼（Grass carp）发病的致病菌,并评估其对健康草鱼的致病性和相关药物的敏感性,本研究从患病草鱼病变器官中分离到一株优势菌,对该分离株的形态学、生长特性、生理生化特性、16S rRNA序列等进行鉴定。结果显示：该菌为革兰氏阴性菌,具有β溶血特性,在LB培养基中生长14 h可达7.41×109 cfu/mL,其理化特性与豚鼠气单胞菌基本符合,16S rRNA序列与参考菌株ATCC15468序列同源性在99.5%以上。基于16S rRNA序列进化分析显示,该分离株与豚鼠气单胞菌同属一个分支,亲缘关系较近。该分离菌株对草鱼的半数致死量（LD50）为4.928×106 cfu,对恩诺沙星、卡那霉素、磺胺甲氧嘧啶等药物比较敏感。综合判断该致病菌为豚鼠气单胞菌,命名为JS分离株,对草鱼具有较强致病性,对部分药物较为敏感。
To identify a bacterium isolated from naturally infected grass carp and evaluate its pathogenicity to the healthy grass carp and the susceptibility to some related drugs, the isolate was investigated through the morpholigy, cultural character, physiological-biochemical characteristics and 16S rRNA sequence analysis methods, inoculated into healthy grass carp and used for the drug sensitivity test. The results showed that the morpholigy, cultural character and physiological-biochemical characteristics of the isolate were basically consistent with Aeromonas caviae. The isolate had 99.5% similarity with Aeromonas based on 16S rRNA sequence and showed closely reletionship with reference strain Aeromonas caviae ATCC15468 in phylogenetic tree. The LDh0 of the isolate was counted to 4.928× 106 cfu by using the Reed-Muench calculation method, and the isolate was sensitive to Enrofloxacin, kanamycin, Sulfamethoxydiazine and some else drugs. Based on these results, the bacterial isolate was identified as Aeromonas caviae and named JS strain, the isolate had strong pathogenicity to the healthy grass carp and was sensitive to some common drugs.
出处
《中国预防兽医学报》
CAS
CSCD
北大核心
2015年第12期912-916,共5页
Chinese Journal of Preventive Veterinary Medicine
基金
广州市科技计划项目(201508020072)
关键词
豚鼠气单胞菌
草鱼
鉴定
药敏试验
Aeromonas caviae
grass carp
identification
sensitivity test
作者简介
何永龙（1983-），男，湖北荆州人，硕士研究生，主要从事预防兽医学研究
通信作者：E-mail：Lzs@haid．com．cn
