一株多重耐药中华鳖源弗氏柠檬酸杆菌的分离鉴定

Isolation and identification of multidrug resistant Citrobacter freundii from diseased soft- shelled turtle,Pelodiscus sinensis

从患典型鳃腺炎病中华鳖(Pelodiscus sinensis)肝脏和腹水处进行细菌接种,分离获得一株细菌。综合菌落形态,16 S rRNA序列进化分析和API细菌生化鉴定系统判定,所得菌株为弗氏柠檬酸杆菌(Citrobacter freundii)(SX43)。动物回归实验显示,分离株对小鼠的半数致死量(LD50)为106.5CFU,显示该菌株具有较强的致病性,可从实验幼鳖体内再次分离到相同的病原菌。常用药物的抗菌敏感性测定显示,菌株SX43对头孢哌酮、头孢曲松、头孢呋辛、复方新诺明、氯霉素高度敏感。

One bacteria was isolated from liver and ascites of diseased soft- shelled turtles（ Pelodiscus sinensis） suffered with parotitis,on the colony morphology,Gram＇s staining,API ID32 E bacterial biochemical identification system and sequence analysis of 16 S rRNA gene,the isolate bacteria was identified as Citrobacter freundii,named SX43. Healthy soft-shelled turtles（ Pelodiscus sinensis） were used for experimental infection with bacterial suspension,the same bacterium could be recovered. Isolate SX43 was demonstrated virulence potential in mouse models, with the median lethal dose（ LD50） in mice at 106. 5CFU. The susceptibility test to antibiotics demonstrated that the bacterial strain SX43 was susceptible to cefoperazone,rocephin,cefuroxim,co- trimoxazole,chloramphenicol.