Pathogens Identification From Bovine Mastitis By PCR Method And Analysis Of Mouse Mastitis Model Established By Artificial Infection Of Bacillus Licheniformis From Bovine Mastitis

Cow mastitis is one of the most important serious problems in the dairy farms.It caused serious economic losses in the dairy farms. At the present stage mastitispathogens were mainly isolated to determine their species based on colonymorphology via the traditional bacterial culture method. The process spends a longtime and unable to accurately determine the types of pathogens in order totreatment of mastitis. Therefore, to develop and improve a kind of rapid, sensitiveand accurate new diagnostic method is urgently indispensable.In this study,40milk samples were collected from clinical mastitis cows.Mastitis pathogens are isolated by the traditional bacterial culture method. DNAwas extracted from bacterial colonies and milk samples. Then the types of bacteriawere identified by PCR method. The main pathogens were isolated, includingAcidithiobacillus thiooxidans, Acinetobacter junii, Agrobacterium tumefaciens,Bacillus cereus, Bacillus licheniformis, Bacillus sp., Enterobacter sp., Klebsiellasp., Pseudomonas sp., Staphylococcus aureus. A rapid, sensitive and specificidentification method of mastitis pathogens was successfully established. It alsoprovided evidences of the rapid diagnosis of dairy mastitis cows in clinic.After the main pathogens were isolated，to further understand the changes inpathological morphology of cow mastitis and seek for an effective remedy in clinic,HSP70and NF-κB were used as target genes to investigate the pathological processand immune pathogenesis.Bacillus licheniformis was selected from the main pathogens in this study.Mouse mammary gland was infected by Bacillus licheniformis to establish themurine mastitis model. Histology and immunohistochemistry were used to observethe morphological changes after infection and expression of HSP70and NF-κB inmammary glands. Results: Symptoms of inflammation appeared in the mouse mammary gland after infection. Histopathologic examination of mammary glandrevealed that polymorphonuclear neutrophils (PMN) were present in alveoli. Theexpression of HSP70and NF-κB in experimental group was significantly increasedcompared with control group and blank group. Conclusion: The results show thatmurine mastitis model was successfully induced by bovine Bacillus licheniformis.The increase of the expression of HSP70and NF-κB in experimental groupindicated that the two genes were involed in the pathological process after bacterialinfection. It provides evidences for disease prevention and treatment for the cowmastitis.