PDF(Pubmed)
Abstract：
Mastitis is considered one of the most widespread infectious disease of cattle and buffaloes, affecting dairy herds. The current study aimed to characterize the Staphylococcus aureus isolates recovered from subclinical mastitis animals in Pothohar region of the country. A total of 278 milk samples from 17 different dairy farms around two districts of the Pothohar region, Islamabad and Rawalpindi, were collected and screened for sub clinical mastitis using California Mastitis Test. Positive milk samples were processed for isolation of Staphylococcus aureus using mannitol salt agar. The recovered isolates were analyzed for their antimicrobial susceptibility and virulence genes using disc diffusion and PCR respectively. 62.2% samples were positive for subclinical mastitis and in total 70 Staphylococcus aureus isolates were recovered. 21% of these isolates were determined to be methicillin resistant, carrying the mecA gene. S. aureus isolates recovered during the study were resistant to all first line therapeutic antibiotics and in total 52% isolates were multidrug resistant. SCCmec typing revealed MRSA SCCmec types IV and V, indicating potential community-acquired MRSA (CA-MRSA) transmission. Virulence profiling revealed high prevalence of key genes associated with adhesion, toxin production, and immune evasion, such as hla, hlb, clfA, clfB and cap5. Furthermore, the Panton-Valentine leukocidin (PVL) toxin, that is often associated with recurrent skin and soft tissue infections, was present in 5.7% of isolates. In conclusion, the increased prevalence of MRSA in bovine mastitis is highlighted by this study, which also reveals a variety of virulence factors in S. aureus and emphasizes the significance of appropriate antibiotic therapy in combating this economically burdensome disease.
摘要：
乳腺炎被认为是牛和水牛最普遍的传染病之一，影响奶牛群。当前的研究旨在表征从该国Pothohar地区的亚临床乳腺炎动物中回收的金黄色葡萄球菌分离株。共有278份来自波托哈尔地区两个地区的17个不同奶牛场的牛奶样本，伊斯兰堡和拉瓦尔品第，收集并使用加利福尼亚乳腺炎测试筛查亚临床乳腺炎。使用甘露醇盐琼脂处理阳性牛奶样品以分离金黄色葡萄球菌。分别使用圆盘扩散和PCR分析回收的分离株的抗菌敏感性和毒力基因。62.2％的样本对亚临床乳腺炎呈阳性，总共回收了70株金黄色葡萄球菌。21%的这些分离株被确定为耐甲氧西林，携带mecA基因.在研究过程中回收的金黄色葡萄球菌分离株对所有一线治疗性抗生素具有耐药性，总共52％的分离株具有多重耐药性。SCCmec分型显示MRSASCCmecIV型和V型，提示潜在的社区获得性MRSA（CA-MRSA）传播。毒力分析显示与粘连相关的关键基因的高流行率，毒素生产，和免疫逃避，比如hla,hlb,clfA,clfB和cap5。此外，潘顿-瓦伦丁杀白细胞素(PVL)毒素，通常与复发性皮肤和软组织感染有关，在5.7%的分离株中存在。总之,这项研究强调了MRSA在牛乳腺炎中的患病率增加，这也揭示了金黄色葡萄球菌中的多种毒力因子，并强调了适当的抗生素治疗在对抗这种经济负担的疾病中的重要性。
