一起致犊牛肺炎牛支原体的分离鉴定

Isolation and Identification of Mycoplasma bovis Inducing Bovine Pneumonia

为调查石河子地区某规模化奶牛场犊牛呼吸道疾病的主要病原,以该牛场犊牛为研究对象,采集2份肺脏组织和45份鼻拭子样品,使用套式PCR方法共检测到阳性样品25份。对阳性样品进行支原体培养,分离到疑似菌株3株,经形态学观察、生化试验、牛支原体16S rRNA引物对菌株进行鉴定。结果显示,3株分离株菌落形态呈典型的“煎蛋样”,Dienes染色可见菌落中心呈深蓝色;分离株均不发酵葡萄糖,不分解甘露醇,不水解精氨酸。PCR扩增分离株16S rRNA基因测序结果显示,分离株与牛支原体国际菌株NADC59(CP042939.1)的同源性最高,同源性均高达99.25%以上。研究结果对牛支原体病病原检测和临床防治具有指导意义。

In order to investigate the main pathogens of respiratory diseases of calves in a large-scale dairy farm in Shihezi,2 lung tissues and 45 nasal swab samples were collected from the calves in the dairy farm.A total of 25 positive samples were detected by nested PCR.The positive samples were cultured with Mycoplasma,and three suspected strains were isolated.The strains were identified by morphological observation,biochemical test and 16S rRNA primers of Mycoplasma bovis.The results showed that the colony morphology of the three isolates was typical‘fried eggs’.Dienes staining showed that the colony center was dark blue.The isolated strains did not ferment glucose,decompose mannitol and hydrolyze arginine.The 16S rRNA gene sequencing results of the PCR-amplified isolates showed that the isolates had the highest homology with the international strain NADC59(CP042939.1),and the homology was more than 99.25%.The results have guiding significance for pathogen detection and clinical prevention of Mycoplasma bovis.