我国五省区奶牛乳腺炎病原菌分布特征及耐药性分析OA

To investigate the composition and antimicrobial resistance characteristics of bacterial pathogens associated with bovine mastitis in different regions of China,and to provide a basis for scientific prevention and control and rational drug use.A total of 130 mastitic milk samples were collected from five provincial-level regions of China,including Shandong,Gansu,Hebei,Shanxi,and Inner Mongolia.The isolated strains were identified and subjected to antimicrobial susceptibility testing to analyze the distribution char-acteristics and resistance profiles of bacterial pathogens.A total of 100 bacterial isolates belonging to 19 genera were identified.Staphylococcus(n=34),Escherichia(n=15),and Streptococcus(n=12)were the predominant bacterial groups.Significant regional differences were observed in bacterial pathogen composi-tion and antimicrobial resistance profiles:Staphylococcus predominated in Shandong and Hebei,whereas Escherichia was the major bacterial group isolated in Inner Mongolia.Escherichia coli exhibited a resist-ance rate of 26.7％to ampicillin,while its susceptibility rates to amikacin,norfloxacin,ciprofloxacin,gentamicin,and polymyxin B were all 100％.Enterococcus faecalis showed multidrug resistance to tetracy-clines,aminoglycosides,and sulfonamides.Bacterial pathogens associated with bovine mastitis in five pro-vincial-level regions of China exhibit significant regional differences in distribution and varying degrees of antimicrobial resistance.Regional pathogen surveillance and antimicrobial susceptibility testing should be strengthened to develop targeted drug use strategies.