摘要

金黄色葡萄球菌是一种常见且主要传染性乳腺炎细菌性病原体。抗生素治疗的治愈率从4％到92％大不相同。金黄色葡萄球菌容易对抗生素产生抗药性，导致持续的不可治愈的乳房内感染，通常导致感染动物剔除。由于其对甲氧西林和万古霉素等常用和最后手段抗菌素产生抗性的臭名昭着的能力以及多重耐药菌株的开发，金葡菌中的抗微生物药物抗性（AMR）在人类医学中极为重要。本研究的目的是评估乳牛乳中金黄色葡萄球菌分离株的AMR和遗传多样性的流行情况。来自田纳西州33个奶牛场的金黄色葡萄球菌分离株（n = 239）通过使用Sensititer系统的肉汤微稀释法对10种抗微生物剂进行了测试。通过脉冲场凝胶电泳（PFGE）评估抗性分离株的遗传多样性。总体而言，金黄色葡萄球菌分离株的AMR从头孢噻呋的低至1.3％至磺胺二甲氧嘧啶的高达25％。在239株金黄色葡萄球菌分离株中，82株（34.3％）对10种抗微生物剂中的至少1种具有抗性。 AMR分离株属于两种主要的PFGE类型，表明抗性分离株中存在显性克隆模式。一般来说，随着时间推移，农场内和农场内AMR的流行率有所变化，四环素耐药性呈上升趋势。在奶牛养殖场合理使用抗菌剂可以减少抗菌素耐药金黄色葡萄球菌的发展。

Staphylococcus aureus is a frequent and major contagious mastitis bacterial pathogen. The antibiotic treatment cure rates vary considerably from 4% to 92%. Staphylococcus aureus readily becomes resistant to antibiotics, resulting in persistent noncurable intramammary infection that usually results in culling of infected animals. Because of its notorious ability to acquire resistance to the commonly used as well as last resort antimicrobials such as methicillin and vancomycin and the development of multidrug-resistant strains, antimicrobial resistance (AMR) in S. aureus is of paramount importance in human medicine. The objective of this study was to evaluate the prevalence of AMR and genetic diversity of S. aureusisolates from milk of dairy cattle. Staphylococcus aureus isolates (n = 239) from 33 dairy farms in Tennessee were tested against 10 antimicrobials by broth microdilution method using the Sensititer system. Genetic diversity of resistant isolates was evaluated by pulsed-field gel electrophoresis (PFGE). Overall, AMR of the S. aureus isolates varied from as low as 1.3% for ceftiofur to as high as 25% for sulfadimethoxine. Out of 239 S. aureus isolates, 82 (34.3%) of them were resistant to at least 1 of the 10 antimicrobials. The AMR isolates belonged to two major PFGE types, indicating the presence of dominant clonal patterns among the resistant isolates. In general, there was a variation of prevalence of AMR within and among farms over time, with an increasing trend in tetracycline resistance. Judicious use of antimicrobials in dairy cattle farms can reduce the development of antimicrobial-resistant S. aureus.

https://www.liebertpub.com/doi/abs/10.1089/fpd.2017.2362