3株猪源多动物链球菌的分离与鉴定

Isolation and Identification of Three Strains of Streptococcus pluranimalium

对3例不同时间送检的病猪的肝、肾脏、肺脏和皮下水肿液进行细菌分离,纯化后分别对其进行革兰染色、生化试验、16S rDNA基因序列分析进行鉴定,小鼠攻毒试验确定分离菌株毒性,药敏试验分析药物敏感性。结果表明:分离菌株为革兰阳性球菌;可以发酵蔗糖、乳糖、麦芽糖等,不能发酵阿拉伯糖、山梨醇、蜜二糖;16S rDNA鉴定结果为多动物链球菌(Streptococcus pluranimalium)。攻毒试验可致小鼠死亡,表明该菌具有强毒性。药敏结果表明,该分离菌株对诺氟沙星、复方新诺明、妥布霉素、庆大霉素等耐药,对阿莫西林、头孢曲松钠、美洛西林等敏感。

In order to diagnose the cause of death of a pig,the kidneys,lungs and subcutaneous edema of the pigs were aseptically collected for bacterial isolation.Then,isolation,Gram staining,biochemical tests,and 16S rDNA gene sequence analysis were performed.The drug sensitivity test was used to analyze drug sensitivity,and the mice were used for toxicity to determine the isolate strain.The results showed that the isolated strain was Gram-positive cocci.It fermented sugar such as sucrose,lactose and maltose,and did not ferment arabinose,sorbitol or melibiose.The result of 16S rDNA identification showed that the isolated bacterium was Streptococcus pluranimalium.The results of drug sensitivity showed that the isolated strain was resistant to streptomycin,tobramycin,kanamycin and gentamicin,and sensitive to amoxicillin,ceftriaxone sodium and mezlocillin.The challenge test showed that it caused death in mice,indicating that the strain is highly toxic.