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Mastitis in dairy cows is one of the most common illnesses in cows, now 奶牛养殖业 harm, economic losses caused by the most serious diseases. Collected from the large-scale dairy farms in some regions of China to identify the cause of mastitis were the main pathogen flora distribution of clinical mastitis milk samples 201 cow mastitis main pathogen crossed separation and biochemical identification method Isolation and identification of test. The results show that, from the submission of the 201 milk samples, aseptic milk samples of 23 milk samples the bacteria was 88.6%. Remaining 178 milk samples isolated nine kinds of 239 bacteria, which closely related to mastitis pathogens, Streptococcus agalactiae, 89 (37.23%), Streptococcus dysgalactiae 53 (22.18%), gold aureus 47 (19.67%) and E. coli 31 (12.97%). The test basic identification of the cow mastitis pathogens flora distribution has important implications for the prevention and treatment of mastitis in dairy cows. Our cows mastitis pathogen resistance to common antibiotics, to guide rational drug. Newly isolated and saved in the past udder inflammation select a different area in the main cause of bacteria Streptococcus agalactiae, Streptococcus dysgalactiae, Staphylococcus aureus and Escherichia coli place strains 20 KB susceptibility paper its resistance to common antibiotics detection. The results showed that the cow mastitis bacteria to most antibiotics are varying degrees of resistance, the resistance rate of 10% to 100%, especially penicillin G, streptomycin and cotrimoxazole strong resistance, the resistance rate of 30% to 100%. Not found in the four kinds of bacteria are highly sensitive to the drug. Four kinds of bacteria relative have strong inhibitory drugs florfenicol levofloxacin, lomefloxacin, norfloxacin and cephalosporins, a sensitivity of 60% to 100%. The test basically identify our cows mastitis pathogen resistance changes, has important implications for clinical therapy. Is prepared efficiently cow mastitis streptococcus capsular polysaccharide - protein conjugate vaccine, to stop the separation and purification of the capsular polysaccharide of Streptococcus lactis process of mastitis in dairy cows were studied. Culture time on the concentration of bacteria with capsular polysaccharides yield influence of fermentation the pH value of impact on the yield of the capsular polysaccharide, removing the ethanol concentration of the nucleic acid, the precipitated polysaccharide required ethanol concentration, temperature and time, to remove hetero The number of protein cold phenol extraction test. Ultimately establish a the following capsular polysaccharide separation and purification process, i.e. fermentation dysgalactiae 8H harvested fermentation broth, adjusted fermentation broth pH 7.0, collected by centrifugation and the supernatant, over 0.22um membrane sterilization concentrated by ultrafiltration of the, 10KD film package 10 times, 25% ethanol precipitated go nucleic acid, the supernatant was collected by centrifugation, 80% ethanol precipitate was eligible for the crude polysaccharides, cold phenol extraction three times to remove contaminating proteins, and to collect sugar layer, dialysis to remove residual phenol, collect the dialysis inner solution, and then washed with 80% ethanol precipitation to obtain a purified streptococcal capsular polysaccharide antigen. Cow mastitis test to establish dysgalactiae Streptococcus capsular polysaccharide antigen extraction purification process is low cost, simple operation, high yield capsular polysaccharide, while at the same time to ensure that the a polysaccharide antigen various indicators are in line with the 2000 edition of \requirements, with a high degree of feasibility and effectiveness. For the preparation of cow mastitis streptococcus capsular polysaccharide - protein conjugate vaccine to lay the foundation.
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