| Bovine mastitis was the mammary-infected disease,which caused by multi-pathogenic microoganism and spread between lactating dairy cows,they are hard to therapy and prevention,also harmful for dairy industry and food security.In this subject,we carry out an epidemiology investtigation of mastitis on lactating dairy cows in the region of Akesu,identification pathogenic microoganism flora and influence of stap aureus N2 isolates biofilm-formation by different animal species blood and Allicin treatment.Test one:Veterinary clinical diagnosis and(lanzhou mastitis test)LMT were used.We investigated the prevalence of sub-clinic and clinic mastitis of lactating dairy cows from Counties-Individual-dairy farmers,dairy farming professional cooperatives and the large-scale farms of Military reclamation State-run cow farms using stratified random sampling in Aksu area.The result shows that:a total of 1136 lactating cows were sampled.The prevalence rate of clinic mastitis is3.5%-4.23%,and that of sub-clinic mastitis was 30%-35%.The rate of clinic mastitis cases recessiving as the increased of parity,while proportal to increased of parity.Trained manual manual milking operation and actively prevention-therapy can promoting the sub-clinic mastitis and increase milk yield.Test two : Pathogenic microorganism were isolated from 288 postive milk samples collected from100 case from Counties-Individual-dairy farmers,Dairy-Farming-Professional-cooperative and the large-scale farms of Military reclamation State-run cow farms in Aksu area.The results showed that bacterial culture was positive in 273 samples of 93 cases,and the positive rate was(273/288)94.8%.Among them,43 samples were triple-infections,accounting for 29.9%,72 were double-infections,accounting for 48.3%,34 were single infections,accounting for 22.8%.A total of 307 strains of bacteria were isolated,161 strains of Staphylococci were isolated,accounting for 52.6%,104 strains of Staphylococcus aureus,accounting for 64.8%,90 strains of Streptococcus,accounting for 29.2%,56 strains of pathogenic Escherichia coli,accounting for 18.2%.Test three: In this experiment,Staphylococcus aureus mastitis isolate N2 was taken as the Material,and XTT assay was used as the detection method.The effects of different concentrations of sheep blood,chicken blood and donkey blood on Staphylococcus aureus biofilm isolate N2 were studied.To study the biofilm of Staphylococcus aureus strain N2 inhibited by three kinds of animal blood.The results showed that sheep blood had the strongest promoting effect on biofilm formation,chicken blood took the second,donkey blood inhibited biofilm-formation,and three animal blood concentration gradients(3%-5%)had the strongest promoting effect on biofilm-formation of Staphylococcus aureus biofilm isolate N2.When the concentration was lower than that,it inhibited biofilm formation.In summary,the effects of different animal blood and different concentration of blood of the same animal on the biofilm-formation of Staphylococcus aureus strain N2 are quite different.Test four: In order to study effect of different concentrations gradient of allicin-add on the biofilm formation of Staphylococcus aureus isolates strain N2.The experiment adopted XTT assay method to measure the influence of the different concentration of allicin-add treatment on biofilm-formation of Staphylococcus aureus isolates strain N2.The results showed that different concentrations gradient of allicin-add treatment of N2 strain negatively correlated with optical density(OD)value.the 512 μg /mL concentration of allicin treatment measured OD value of 0.1 below,presenting strong inhibitory effect on the biofilm-formation of mastile Staphylococcus aureus isolate N2,above 4 μg / mL concentration of allicin treatment measured OD values below 0.4,presenting obviously inhibitation of effect on the biofilm-formation of mastile Staphylococcus aureus isolate N2.below 4 μg / mL concentration of allicin treatment measured OD values above 0.4,presenting slightly inhibitation of effect on the biofilm-formation of mastile Staphylococcus aureus isolate N2. |
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