Study On Isolation And Identification The Main Pathogenic Bacteria Of Dairy Cattle Mastitis And Detecting Antibody Of The Multi-vaccine Of Mastitis

Dairy cattle mastitis was one of the common and frequent diseases, which had complex etiological factor and difficult to control, it not only made economically losses to the domestic industry of dairy cattle but also endangered human health. Utilizing the vaccines to prevent and control dairy cattle mastitis was a kind of safe, economical and effective method. In this study, the main pathogenic bacteria of mastitis were isolated and identified, an indirect ELISA was initial developed for detecting serum antibody of the multi-vaccine of mastitis. It provided the basis for evaluating the effect of the vaccine and further studying.89 milk samples of the clinical and hidden mastitis were collected from some large dairy farms, the main pathogenic bacteria of mastitis were isolated and identified. 137 strains of bacteria were isolated from 84 milk specimens, but no strains of bacteria were isolated from the other 5 ones. There were 52 strains of Streptococcus agalactiae, 20 strains of Streptococcus dysgalactiae, 29 strains Staphylococcus arueus and 22 strains of Escherichia coli, the rate was 37.96, 14.60, 21.17 and 16.06 percent respectively, other 14 strains was 10.21 percent. The total positive rate of Streptococcus, Staphylococcus and Escherichia coli was 89.79 percent which were the main pathogenic bacteria of the mastitis. Results of sensitivity to drug showed that the strains were very sensitive to cephalosporinV, neomycin , ciprofloxacin and amikacin, but insensitive to penicillin, streptomycin, ampicillin and sulfamethoxazole compound, which producted drug resistant. According to practical situation, explore comprehensive measures for the prevention and control of dairy cattle mastitis, which provided scientific basis for prevention and therapy of mastitis.The soluble whole cell antigens were made by ultrasonic method. Base on the conventional ELISA method, through optimizing reaction system, an indirect ELISA was initial developed for detecting serum antibody of the multi-vaccine of mastitis. The result showed that the reaction system of three kinds of antigens was coincided, the optimal conditions of reaction were as follows: The optimal coating concentration of antigens was 4.0～6.0μg/mL, coating for 24h at 4℃; 1%BSA-PSBT was added as the optional blocking for 30minutes at 37℃; the optimal dilution of serum samples was 1∶200, the working concentration of HRP-labeled goat anti-bovine IgG was 1:20 000, reacting for 30minutes at 37℃; Substrate system of TMB coloring.