Isolation,Identification And Drug Resistance Of Staphylococcus From Dairy Cow Mastitis In Henan Province

The health of cow mammary gland directly affects the quality and safety of dairy products.With the development of society,the demand for milk and dairy products is also increasing,its quality and safety is closely related to people’s health.Pathogenic microorganism is the main factor leading to dairy cow mammary disease,and staphylococcus is one of the main pathogenic bacteria causing dairy cow mastitis,which brings huge losses to dairy farming and the quality and safety of dairy products.With the development of dairy industry and the domestic attention to dairy disease prevention and control,the level of Dairy Mastitis prevention and control has been significantly improved.At the same time,the types of pathogenic bacteria and the dominant flora have also changed.For example,cow mastitis caused by Staphylococcus is on the rise,and there are a lot of reports at home and abroad.This study investigated the prevalence and drug resistance of Staphylococcus mastitis in dairy cows in Henan Province.The following studies were conducted:1.A total of 74 samples were collected from dairy farms in Henan Province.A total of 89 strains were collected and analyzed by 16S rDNA sequencing and NCBI online sequence comparison software blast,Among 89 strains,62 strains were Staphylococcus,belonging to 7 species.The isolation rate of Staphylococcus chromogenes was 22.47%.The isolation rate of Staphylococcus haemolyticus was 7.87%.The isolation rate of Staphylococcus epidermidis was 5.62%.The isolation rate of Staphylococcus warneri was 5.62%.The isolation rate of Staphylococcus aureus was 4.49%.The isolation rate of Staphylococcus gallinarum was 2.25%.The isolation rate of Staphylococcus hyicus was 1.12%.The results showed that Staphylococcus chromogenes,Staphylococcus haemolyticus,Staphylococcus epidermidis and Staphylococcus warneri were the main causes of mastitis in dairy cows in Henan Province.2.According to the usage of antibiotics,10 kinds of common antibiotics were selected,and the drug sensitivity of 62 strains of Staphylococcus was tested by MH agar culture.The results showed that 62 strains of bacteria showed certain drug resistance,the strongest resistance to ampicillin,oxacillin and ceftiofur,and more sensitive to tetracycline and sulfamethoxazole.The resistance rates of 20 strains of S.chromogenes to ampicillin,oxacillin,ceftiofur and clindamycin were 100.00%,85.00%,75.00%and 70%respectively.Seven strains of Staphylococcus haemolyticus had high resistance to ampicillin,oxacillin,ceftiofur,clindamycin and enrofloxacin,and the resistance rate was more than 85%.Staphylococcus aureus was resistant to ampicillin,oxacillin and tetracycline,but sensitive to ceftiofur,gentamicin and sulfamethoxazole.62 strains were 100%multi drug resistant.3.The whole genome sequencing of Staphylococcus epidermidis 4-1 was completed by using the second generation molecular sequencing technology.Assemble and annotate the sequenced sequences.On this basis,different databases were used to predict protein function,and a gene sequence of SCCmec was analyzed.