Construction And Clinical Experiment Of Polyvalent Virulence Factor Vaccine Against S. Aureus Inducing Mastitis In Cows

Research on staphylococcus aureus vaccine of dairy cow mastitis has been going on for decades. However, none of genetic engineering vaccine, live or inactivated vaccine has obtained significant immune effect.The experiment has been operated as follows:Firstly, cattle gene fragments IgG-Fc were obtained by separation of the peripheral blood lymphocytes cloning. Secondly, by the method of PCR overlap extension, genes IgG-Fc and recombinant genes FnBPB-ClfA, which were prepared in the laboratory, were linked tendemly to establish cow genes Fc-FnBPB-ClfA. Thirdly, in order to do the soluble induced expression of target protein, Fc-FnBPB-ClfA was cloned to the prokaryotic expression vector pET32a (+). Finally,10 dairy cows, diagnosed with recessive mastitis by CMT, were immunized twice with aluminium salt adjuvants. The first immune used intramuscular injection to immunize these cows 14 days before the dry period. The second immune used papillary duct injecion during the dry period. Then the serum seperated by immune seperate technique were tested by indirect ELISA method in order to evaluate the immune effect of these 10 cows. The results were satisfactory. After calving and starting being milked normally, Somatic cell count were surveyed again.10 cows were immunized less than 100,000, which also improves a good immune effect.In conclusion, the experiment provides a reliable theory basis for the dairy cow mastitis vaccine research by the way to produce an immune effect for the dairy cows.