牛支原体广西分离株的致病性研究

The study on the pathogenicity of Mycoplasma bovis isolated in Guangxi

为了研究牛支原体广西分离株的致病性,试验将10株牛支原体广西分离株（G12、BS2、LA、GL1、BS1、NN4、NN5、GL3、NN1和GG）以相同剂量注射到7日龄健康SPF鸡胚尿囊腔上,即为10个感染组,同时设阴性对照组和空白对照组,连续培养7 d,观察胚体的生长变化情况,同时收集尿囊液进行PCR鉴定。结果表明：10株分离株100%感染鸡胚,病死率为10%-50%,其中BS2引起的病死率最高;死亡鸡胚的胚体表面有充血、出血现象,与阴性对照组和空白对照组相比,大部分存活胚的胚体发育缓慢;10个感染组的尿囊液经PCR扩增得到相应的目的片段。说明鸡胚感染了牛支原体,经初步筛选可知广西分离株BS2的毒力较强。

The aim of the present study was to investigate the pathogenicity of Mycoplasma bovis isolated in Guangxi. Ten isolated strains（10 infected groups） of Mycoplasma bovis（G12,BS2,LA,GL1,BS1,NN4,NN5,GL3,NN1 and GG） were injected into the allantoic cavity of7 day healthy SPF chicken embryos in the same doze. Negative control group and blank control group were also established simultaneously. The growth situation of them was observed after continuous culture 7 days. At the same time,the allantoic fluid in ten groups was collected for PCR identification. The results showed that infection rate was 100%,and the mortality was 10%-50% in those 10 groups,and especially BS2 strain was the highest in mortality. There was a phenomenon of hyperaemia and hemorrhage in the dead embryos. Compared with the negative control and blank control group,most survival embryos developed more slowly. Furthermore,the corresponding target fragments were obtained by PCR amplification of allantoic fluid in 10 infected groups. The results indicated that the chicken embryos had been infected with Mycoplasma bovis,and the BS2 strain had stronger pathogenicity than that of others.