The Study On Growth Properties And Pathogenesis Of Mycoplasma Bovis

Mycoplasma bovis is an important and emerging pathogen which can induce pneumonia, mastitis, arthritis, reproductive tract injury and keratitis in cattle. It is often found infected with other bacteria and pathogens. Currently, the study is focus on the diagnosis. And the research about M.bovis in abroad is deeper. In our country, M.bovis had been found later and spread slowly, so few studies had been reported. At the same time, there are fewer studies on the characteristics, pathogen and the pathogenic mechanism. Therefore, we make our research relevance to the two aspects of M.bovis.With many methods, it can be known the growth characteristics and virulence for each isolates of M.bovis, and dominant epidemic strain can be selected for the later development of ELISA diagnostic kits and vaccine development.1 The study on the isolation, cultivation and identification of mycoplasma bovisThis test was used the improvement mycoplasma medium for pathogen isolation, cultivation and purification of M.bovis from the six lung tissues which were within serious sicked or dead because of acute respiratory diseases. Through the PCR identifation, it was proved to be M. bovis inffected. The improved liquid medium is suitable for growth and breeding, especially in time when the color changing of medium only needs 24h for average. At the same time, the PCR for M.bovis dignosis is more sensitivity and specialty in clinical disease diagnosis.2 The study on the growth properties of mycoplasma bovisThe pure cultures of M.bovis isolates were carried out to study the growth properties of M.bovis. M.bovis can stain with Gram and Giema.Colonies of M.bovis often have a typical fried-egg apperance, staining purple with Giema strain, staining blue with Dienes'stain and retain their color indefinitely.Biochemical tests have shown that M.bovis can not use neither glucose or arginine hydrolysis,and only use organic acids such as lactate. The Growth phases had shown that every isolates of M.bovis which arrived the exponential phase were after being cultured 48h later. And during this period, the pH was decreased in the broth medium.3 The study on the pathogen of mycoplasma bovisThe tests use the six pure isolates of M.bovis to infect the healthy chick embryos and SPF BALB/c mice. The results have shown that every isolates of M.bovis can grow well in chick embryos and cause massive death of chick embryos, the death rate of every group showed a significant difference(P<0.05). BALB/c mice effeted experiments have shown that the mice of the effected groups have no obvious clinical respirataton disease symptoms and lung pathological leision, and without isolated and identified by the etiology pathogen dignosis. However, M.bovis infection can cause weight loser and lung index, spleen idex rising.In summary, the M. bovis dignosis in lab can reference to the methods which were set up in our study. Meanwhile, Mbovis will arrive the exponential phase after being cultured 48h later, can guide preservation and multiplication. The chick embryos can be a disease animal model in pathogenic study, but SPF BABL/c mice is to be considerate. At last, the four isolates strains can be an optional antigen for ELISA and vaccine prepatation.