Isolation And Identification Of Pathogenic Bacterium From Subclinical Mastitis And Pharmic Sensitivity Test

The objective is to investigate etiological situation of the bovine subclinical mastitis in Harbin, in order to provide scientific and available method for prevention and cure. The samples from the environment of cowsheds and the milk of the cattle infected by bovine subclinical mastitis were collected from several typical cattle farms. We isolated and identified the bacterium in the samples, and measure its sensitivity against medicine. Then, the synthetical method of prevention and cure for bovine subclinical mastitis was established combined with the cattle farm management and current situation of prevention and cure for the cattle disease.In the experiment for isolating the bacterium from environment samples and identifying the sensitivity against medicine, we selected four cow sheds from four big cattle farms and collect 60 samples. 194 strains bacterium has been isolated including 67 strains gram-positive coccus,1 strain gram-negative coccus,5 strains gram-positive bacillus, 121 strains gram-negative bacillus. The result of sensitivity against three kinds pharmacies shows that HuiFuXing and LiKeLing are prefered.In the experiment for investigating the pathogeny for bovine subclinical mastitis and analysing its sensitivity against medicine, we collected 60 milk samples from the cattle infected by bovine subclinical mastitis and isolated 116 strains bacterium from 13 species, including 35 strains staphylococcus aureus,4 strains staphylococcus epidermidis,3 strains staphylococcus saprophyticus,16 strains staphylococcus agalactiae,15 strains streptococcus dysgalactiae,9 strains streptococcus uberis,3 strains streptococcus faecalis, 24 strains escherichia coli, 2 strains shigella, 2 strains klebsiella,1 strain actinobacillus,1 strain corynebacterium, 1 strain bacillus pyocyaneus. In the 12 kinds of selected medicine, the activity of ofloxacin, norfloxacin and cefamandole against bacterium is much higher, the next are gentamycinum, cefalexin and amoxicillin, while, the activity of tetracyclineum, penicillin, streptomycinum is low.The result demonstrates that staphylococcus and streptococcus are main bacterium caused bovine subclinical mastitis,the next is escherichia coli. Bovine subclinical mastitis also relates to the environment bacterium. The analysis of sensitivity against medicine of the pathogenyisolated from the milk samples indicates that the most sentitive medicine to the pathogeny is ofloxacin, norfloxacin and cefamandole, and the next is gentamycinum, cefalexin and amoxicillin.