Analysis Of The Pathogenic Microbial Flora And The Genotyping Of Staphylococcu Aureus Of Cows Subclinical Mastitis

The experiments used the methods of isolation, identification and denaturinggradient gel electrophoresis (DGGE) to analysis the structure of the microbial floraof cows subclinical mastitis milk, to survey the distribution of bacteria and fungi inthe milk and research the microflora structure of subclinical mastitis milk on theinfluence of the cow mastitis treatment, meanwhile provide theoretical basis andexperimental basis for the treatment of dairy cow mastitis. Investigation thegenotype distribution of Staphylococcus aureus of cow mastitis by the technologyof random amplified polymorphic DNA (RAPD) in Shanghai region, and exploredthe relationship between genotype and resistance of different Staphylococcusaureus isolates,it was important for Staphylococcus aureus vaccine and theprevention and treatment of cow mastitis. The results showed that:The major pathogenic bacteria resulting in cow subclinical mastitis wereEscherichia coli, Staphylococcus aureus, Streptococcus agalactiae, Staphylococcusepidermidis and Klebsiella. After conducting traceable DGGE analysis on milksamples of E. coli mastitis, it was found that Pseudomonas, Bacillus, Streptococcus,Serratia,Vibrio and other pathogenic bacteria were included in the milk samplesexcept E. coli. Besides, the microbial community structure in milk samples wasclosely related to the healing of cow mastitis. The more complicated the communitystructure, the more time it should spend in healing. The mould infection rate of cowsubclinical mastitis milk sample was8.05%and the rate of yeast infection was2.30%. The anaiysis of fungal infection milk samples’ community structure showsthat the pathogen divided into three categories: Aspergillus, Yeast and Penicillium.It is found that there are2to8kinds of fungi in milk. Aspergillus fumigatus,Aspergillus niger and Penicillium decumbens were almost universally included inmilk samples. The63strains of Staphylococcus aureus have produced differentlevels of resistance on a variety of commonly used antibiotics, in particular, it havebeen completely resistant to ampicillin and amoxicillin, the resistance of each farmstrains was significant difference to those antibiotic. The63Staphylococcus aureusstrains were divided into nine genotypes, Ⅵ type was the main genotype and up to47.62%of the total. The genotype distribution of each farm significant difference, the genotype of Z farm and D farm distributed more evenly, but W farm and X farmgenotype distributed concentrated. It wasn’t correspond to comparing therelationship between genotype and durg resistance of Staphylococcus aureus.