[目的]明确新疆某规模化牧场奶牛临床型乳房炎的主要致病菌种类及其耐药性,为制定针对性防控措施提供科学依据。[方法]无菌采集15 头患病奶牛的乳汁样本,通过细菌分离纯化、形态学观察、生理生化鉴定及16S rRNA分子鉴定确定病原菌种类,并采用K-B药敏试验检测其对12 种常用抗生素的敏感性。[结果]共分离出21 株细菌,其中大肠杆菌11 株（52.38%）、金黄色葡萄球菌7 株（33.33%）和链球菌3 株（14.28%）。药敏试验显示,大肠杆菌对阿莫西林、克林霉素等完全耐药,对庆大霉素、恩诺沙星中度敏感;金黄色葡萄球菌对多粘菌素耐药,但对其他抗生素高度敏感;链球菌对四环素、恩诺沙星等高度敏感。混合菌药敏试验表明,恩诺沙星、氧氟沙星和四环素抑菌效果最佳。[结论]该牧场奶牛乳房炎主要由大肠杆菌、金黄色葡萄球菌和链球菌混合感染引起,推荐使用恩诺沙星、氧氟沙星和四环素进行治疗,同时结合定期检测、环境改善和科学消毒等综合措施,可有效防控乳房炎的发生与传播。

[Objective] To identify the main pathogenic bacteria causing clinical mastitis in dairy cows at a large-scale farm in Xinjiang and determine their antibiotic resistance profiles,providing a scientific basis for targeted prevention and control strategies. [Method] Aseptically collected milk samples from 15 cows with clinical mastitis were subjected to bacterial isolation and purification,morphological observation,physiological and biochemical identification,and 16S rRNA molecular characterization. The antibiotic susceptibility of the isolated strains was assessed using the Kirby-Bauer （K-B） disk diffusion method against 12 commonly used antibiotics. [Result] A total of 21 bacterial strains were isolated,including Escherichia coli （11 strains,52.38%）,Staphylococcus aureus （7 strains,33.33%）,and Streptococcus spp. （3 strains,14.28%）. Antibiotic susceptibility testing revealed that E. coli exhibited complete resistance to amoxicillin and clindamycin but moderate sensitivity to gentamicin and enrofloxacin. S. aureus was resistant to polymyxin but highly sensitive to most other antibiotics. Streptococcus spp. showed high sensitivity to tetracycline and enrofloxacin. Mixed bacterial susceptibility testing indicated that enrofloxacin,ofloxacin,and tetracycline were the most effective treatments. [Conclusion] Clinical mastitis in this farm was primarily caused by mixed infections of E. coli,S. aureus,and Streptococcus spp. The recommended treatment regimen includes enrofloxacin,ofloxacin,and tetracycline,complemented by comprehensive measures such as regular screening for subclinical mastitis,environmental management improvements,and strict disinfection protocols to effectively control the occurrence and spread of mastitis.