Investigation Of Etiology And Rapid Diagnosis For Dairy Cow Mastitis In Shanxi Province

To investigate the mastitis morbidity of 1500 cows in Shanxi scaled cattle farms and cattle farmer of province and analyze the main cause of mastitis pathogens were investigated. Using molecular biology techniques, PCR method to detect mastitis pathogen single, integrated multi-pathogen detection PCR optimum conditions, to determine the multiplex PCR conditions, and to study its specificity and sensitivity.The results were as follows:1, epidemiological survey found that staphylococcus, streptococcus, E. coli as the main pathogens of mastitis,78.6% of the total number of bacteria. Susceptibility tests showed that staphylococcus, streptococcus, E. coli bacteria on the three commonly used drugs ampicillin, streptomycin, amikacin low sensitive or not sensitive to doxycycline, clindamycin, ceftriaxone Pine sodium, levofloxacin and other drugs moderately or highly sensitive.2, multiplex PCR showed Streptococcus lactis strain annealing temperature 49.4～55.3℃ amplification effect is better; aureus strain annealing temperature of 55.3～57.6℃ amplification effect is better; E. coli strain annealing temperature to 46.3～53.3℃ ideal amplification. Streptococcus agalactiae primers final concentration 1.5-1.75umol/L effect is better; Staphylococcus aureus final concentration of primers to 1.25～2.0umol/L effect as well; E. coli final concentration of primers to 0.75～1.Oumol/L the effect is better. Amplification agalactiae final concentration of dNTP to 0.1～0.2mmol/L is preferred; Staphylococcus aureus to 0.15mmol/L optimum; E. coli 0.075～0.3mmol/L can be. Streptococcus agalactiae isolates, four strains of Staphylococcus aureus and Escherichia coli standard strain four primers were used to amplify its own conditions optimized single multiplex PCR amplification, the results are at 162bp,439bp,544 bp occurring at The experimental design is consistent with the nucleic acid amplified fragment.3, PCR assay and bacterial culture of Staphylococcus aureus, Streptococcus agalactiae no difference test in Escherichia coli and significantly, PCR assay sensitivity was significantly higher than bacterial culture. It can be used for dairy and quality inspection and supervision unit applied to actual needs. Conclusion:By optimizing the multiplex PCR conditions, PCR assay sensitivity was significantly higher than bacterial culture. It can be used for dairy and quality inspection and supervision unit applied to actual needs.From the above, we come to conclusions that the staphylococcus, streptococcus, E. coli as the main pathogens of mastitis in Shanxi province,78.6% of the total number of bacteria. Susceptibility tests showed that staphylococcus, streptococcus, E. coli bacteria; and those bacteria were sensitive to doxycycline, clindamycin, ceftriaxone, and levofloxacin. PCR assay and bacterial culture of Staphylococcus aureus can be used for Staphylococcus aureus identification, PCR is more sensitive and suitable for detecting and monitoring of dairy farm and products.