Antimicrobial resistance (AMR) is one of the top global health threats of the 21th century. Recent studies are increasingly reporting the rise in extended-spectrum beta-lactamases producing Enterobacteriaceae (ESBLs-Ent) in dairy cattle and humans in the USA. The causes of the increased prevalence of ESBLs-Ent infections in humans and commensal ESBLs-Ent in dairy cattle farms are mostly unknown. However, the extensive use of beta-lactam antibiotics, especially third-generation cephalosporins (3GCs) in dairy farms and human health, can be implicated as a major driver for the rise in ESBLs-Ent. The rise in ESBLs-Ent, particularly ESBLs-Escherichia coli and ESBLs-Klebsiella species in the USA dairy cattle is not only an animal health issue but also a serious public health concern. The ESBLs-E. coli and -Klebsiella spp. can be transmitted to humans through direct contact with carrier animals or indirectly through the food chain or via the environment. The USA Centers for Disease Control and Prevention reports also showed continuous increase in community-associated human infections caused by ESBLs-Ent. Some studies attributed the elevated prevalence of ESBLs-Ent infections in humans to the frequent use of 3GCs in dairy farms. However, the status of ESBLs-Ent in dairy cattle and their contribution to human infections caused by ESBLs-producing enteric bacteria in the USA is the subject of further study. The aims of this review are to give in-depth insights into the status of ESBL-Ent in the USA dairy farms and its implication for public health and to highlight some critical research gaps that need to be addressed.

中文翻译：

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美国奶牛场产生肠杆菌科细菌的超广谱 β-内酰胺酶及其对公共卫生的影响

抗菌素耐药性 (AMR) 是 21 世纪全球最大的健康威胁之一。最近的研究越来越多地报道，美国奶牛和人类中产生肠杆菌科细菌(ESBLs-Ent) 的广谱 β-内酰胺酶有所增加。人类 ESBLs-Ent 感染和奶牛场共生 ESBLs-Ent 感染率增加的原因大多未知。然而，在奶牛场和人类健康中广泛使用 β-内酰胺类抗生素，尤其是第三代头孢菌素 (3GCs)，可能是 ESBLs-Ent 上升的主要驱动力。ESBLs-Ent 的增加，特别是 ESBLs-大肠杆菌和 ESBLs-克雷伯氏菌美国奶牛的品种不仅是一个动物健康问题，也是一个严重的公共卫生问题。ESBLs-大肠杆菌和-克雷伯氏菌spp. 可以通过与载体动物直接接触或通过食物链或环境间接传播给人类。美国疾病控制和预防中心的报告还显示，由 ESBLs-Ent 引起的社区相关人类感染持续增加。一些研究将人类 ESBLs-Ent 感染率升高归因于奶牛场频繁使用 3GC。然而，ESBLs-Ent 在奶牛中的地位及其对美国产 ESBLs 肠道细菌引起的人类感染的贡献是进一步研究的主题。本次审查的目的是深入了解 ESBL-Ent 在美国奶牛场的状况及其对公共卫生的影响，并强调一些需要解决的关键研究空白。