摘要

  抗菌素耐药性已成为对公共卫生的全球威胁，因为在世界范围内报道了携带不同抗菌素耐药基因 (ARG) 的多重耐药 (MDR) 细菌，并且动物被描述为 ARG 的宿主。食品基质中存在抗微生物细菌和 ARG 对公共健康构成威胁。本研究旨在研究巴西农场奶牛和小牛粪便样本中重要抗菌剂和遗传元素的临床相关 ARG 的存在。本研究共采集21份粪便样本，提取可培养需氧菌DNA。通过PCR研究了57个ARGs和23个遗传元件并通过测序确认。检测到几种对 β-内酰胺类、四环素类、氟喹诺酮类、磺胺类、苯酚、氨基糖苷类、糖肽类和大环内酯类产生抗性的 ARG。总共 200 个扩增子来自 23 个 ARG（blaCTX-M-Gp2、blaCMY、blaSHV、tetA、tetB、tetC、qepA、qnrB、qnrS、oqxA、oqxB、vanC1、vanC2/3、aadA、suls、2uls1B 、mefAE、floR、cmla、aadA、aph(3')-Ia、aac(3')-Ia)和来自 12 个遗传元件的 145 个扩增子（IncF、IncFIA、IncFIB、IncI1、IncY、IncU、IncK、IncP、检测到 IncR、IncHI1、ColE 样、intI1)。本研究中提出的结果引起人们对全球奶牛场抗菌素耐药性监测的关注。 MDR 细菌和 ARG 可以传播到不同来源，包括奶制品，这是全球消费量最大的产品之一，对人类健康构成潜在风险

 Antimicrobial resistance has become a global threat to public health since multidrug-resistant (MDR) bacteria have been reported worldwide carrying different antimicrobial resistance genes (ARGs), and animals have been described as a reservoir of ARGs. The presence of antimicrobial-resistant bacteria and ARGs in the food matrix is a risk to public health. This study aimed to research the presence of clinically relevant ARGs for important antimicrobials and genetic elements in fecal samples from dairy cows and calves on a Brazilian farm. In this study, a total of 21 fecal samples were collected, and then, the DNA of cultivable aerobic bacteria was extracted. Fifty-seven ARGs and twenty-three genetic elements were researched by PCR and confirmed by sequencing. Several ARGs that confer resistance to β-lactams, tetracyclines, fluoroquinolones, sulphonamides, phenicols, aminoglycoside, glycopeptides, and macrolides were detected. A total of 200 amplicons from 23 ARGs (blaCTX-M-Gp2, blaCMY, blaSHV, tetA, tetB, tetC, qepA, qnrB, qnrS, oqxA, oqxB, vanC1, vanC2/3, aadA, sul1, sul2, sul3, ermB, mefAE, floR, cmlA, aadA, aph(3′)-Ia, aac(3′)-Ia), and 145 amplicons from 12 genetic elements (IncF, IncFIA, IncFIB, IncI1, IncY, IncU, IncK, IncP, IncR, IncHI1, ColE-like, intI1) were detected. The results presented in this study call attention to the monitoring of antimicrobial resistance in dairy farms worldwide. MDR bacteria and ARGs can spread to different sources, including milk products, which are one of the most consumed products worldwide, representing a potential risk to human health.

   https://link.springer.com/article/10.1007/s42770-020-00265-6