The present study aimed to provide a detailed characterization of coagulase-negative staphylococci (CoNS) isolated from cows and buffaloes with mastitis. The study included seventy-five CoNS isolates (60 came from cattle and 15 from buffaloes) originating from 68 individual quarters of 67 dairy cows (53 cattle and 14 buffaloes). The animals belonged to five different small holding dairy herds (n = 140 cows) that show clinical or subclinical mastitis. CoNS isolates were phenotypically characterized using MALDI-TOF-MS and were further genotypically characterized by microarray-based assays. Furthermore, the antimicrobial susceptibility of CoNS strains which carried the mecA gene was examined by broth microdilution. The occurrence of CoNS in the respective five herds was 10.5%, 14.7%, 14.8%, 12.8%, and 9.9%, with an average of 12.4%. Six different CoNS species were identified: S. sciuri (n = 37; 30 from cattle and 7 from buffaloes), S. chromogenes (n = 14; 8 from cattle and 6 from buffaloes), S. haemolyticus (n = 10; nine from cattle and one buffalo), S. xylosus (n = 10; nine from cattle and one buffalo), S. hyicus (n = 2), S. warneri (n = 1), and unidentified CoNS (n = 1). Twenty percent (20%) of CoNS isolates (17.3% of cattle origin) carried at least one antimicrobial resistance gene, while 4% of the isolate including two isolates of S. haemolyticus and one S. warneri of cattle origin carried the mecA gene and were phenotypically identified as methicillin-resistant strains. The genes detected were blaZ (16%), followed by tet(K) (8%), aacA-aphD (4%), aphA3 (2.6%), msr(A) (2.6%), [far1 (2.6%), and fusC (2.6%)], sat (2.6%), and cat (1.3%) conferring resistance to penicillin, tetracycline, gentamicin, neomycin/kanamycin, erythromycin, fusidic acid, streptothricin, and chloramphenicol, respectively. The majority of investigated CoNS strains displayed considerably low prevalence of resistance genes, while resistance to more than three antibiotics was found in S. haemolyticus and S. warneri. Implementing effective preventive measures is, therefore, important for limiting the transmission of CoNS, rather than using antibiotics to control mastitis in bovines.

本研究旨在提供从患有乳腺炎的牛和水牛中分离出的凝固酶阴性葡萄球菌（CoNS）的详细特征。该研究包括来自67头奶牛的68个单独的季度（53头牛和14头水牛）的75个CoNS分离株（60头牛和15头水牛）。这些动物属于 显示临床或亚临床乳腺炎的五个不同的小型持奶牛群（n = 140头母牛）。使用MALDI-TOF-MS对CoNS分离物进行表型鉴定，并通过基于微阵列的分析对基因型进行进一步鉴定。此外，携带mecA的CoNS菌株的抗菌敏感性通过肉汤微量稀释检查基因。五种畜群中CoNS的发生率分别为10.5％，14.7％，14.8％，12.8％和9.9％，平均为12.4％。六个不同的凝固酶阴性葡萄球菌物种鉴定：松鼠葡萄球菌（Ñ  = 37; 30从牛和7从水牛），S.产色（Ñ  = 14; 8，从牛和6从水牛），溶血葡萄球菌（N  = 10; 9来自牛和一个水牛），木糖链球菌（n  = 10;来自牛和一个水牛的9种），hyicus（n  = 2），华氏链球菌（n  = 1）和未识别的CoNS（n = 1）。20％（20％）的CoNS分离株（占牛源的17.3％）带有至少一个抗菌素耐药基因，而4％的分离株（包括两个溶血链球菌和一个来自牛的华氏链球菌）带有mecA基因，而在表型上被鉴定为耐甲氧西林的菌株。检测到的基因为blaZ（16％），其次是tet（K）（8％），aacA-aphD（4％），aphA3（2.6％），msr（A）（2.6％），[ far1（2.6％）和fusC（2.6％）]，sat（2.6％）和cat（1.3％）分别对青霉素，四环素，庆大霉素，新霉素/卡那霉素，红霉素，夫西地酸，链霉素和氯霉素具有抗药性。大多数研究的CoNS菌株显示出很低的耐药基因流行率，而在溶血链球菌和华氏链球菌中发现了对三种以上抗生素的耐药性。因此，采取有效的预防措施对于限制CoNS的传播非常重要，而不是使用抗生素来控制牛的乳腺炎。