我国奶牛乳房炎耐药菌基因分布机制与反复发作生理路径

Mechanisms of antimicrobial resistance gene distribution and pathophysiological pathways of recurrence of bovine mastitis in China

摘要:

奶牛乳房炎是制约我国奶业高质量发展的关键因素，而耐药菌的流行与感染反复发作已成为当前防控体系面临的严峻挑战。长期抗生素筛选压力虽能暂时缓解临床症状，却显著加速了多重耐药(multidrug-resistant, MDR)菌的演变与扩散，导致治疗失败率上升及病例向慢性化转变。流行病学数据显示，我国奶牛乳房炎病原谱以金黄色葡萄球菌、链球菌属及肠杆菌科细菌为主，其耐药基因通过质粒、转座子及整合子介导的水平基因转移机制实现跨菌种及跨区域传播。生物膜形成、外排泵激活、靶点修饰及胞内逃逸等机制与乳腺微环境相互作用，共同构成了病原菌对宿主免疫和药物攻击的防御屏障。结合“肠-乳轴”介导的内源性炎症及代谢紊乱规律，本文系统综述了我国奶牛乳房炎耐药菌的区域流行特征与分子扩散机制，深入解析了感染反复发作的病理基础，并前瞻性地提出了从精准诊断到替代治疗的综合治理策略，为我国奶牛乳房炎的科学防控提供理论支撑。

Abstract:

Bovine mastitis is a key factor restricting the high-quality development of China’s dairy industry, while the prevalence of antimicrobial-resistant bacteria and recurrent infections have become severe challenges for the current prevention and control system. Although long-term antibiotic selection pressure may temporarily alleviate clinical symptoms, it significantly accelerates the evolution and dissemination of multidrug-resistant (MDR) pathogens, leading to rising treatment failure rates and a transition toward chronic disease. Epidemiological data indicate that the pathogen spectrum of bovine mastitis in China is dominated by Staphylococcus aureus, Streptococcus spp., and Enterobacteriaceae, with resistance genes propagating across species and regions through horizontal gene transfer (HGT) mediated by plasmids, transposons, and integrons. Furthermore, mechanisms such as biofilm formation, efflux pump activation, target modification, and intracellular escape interact with the mammary microenvironment to establish a robust defense barrier against host immune clearance and antimicrobial agents. Incorporating the principles of endogenous inflammation and metabolic dysregulation mediated by the “gut-mammary axis”, this paper systematically reviews the regional prevalence and molecular dissemination mechanisms of resistant pathogens in China. It provides an in-depth analysis of the pathological basis of recurrence and prospectively proposes comprehensive management strategies—ranging from precision diagnosis to alternative therapies—aiming to provide a theoretical foundation for the scientific control of bovine mastitis.