摘要

       虽然已在猪中表征了培养病原体的抗菌素耐药性特征，但尚未阐明与发育中的胃肠道微生物群相关的抗菌素耐药性基因 (ARG) 的波动。本研究的目的是评估围产期土拉霉素 (TUL) 过敏反应对断奶前仔猪粪便微生物群发育动态及其伴随的抗菌素耐药性的影响。 16 只幼仔在出生后立即接受两种治疗 [对照组（CONT；生理盐水 1cc IM）和 TUL 组（TUL；2.5 mg/kg IM）] 之一。在第 0 天（治疗前）以及在治疗后第 5 天和第 20 天再次收集深层粪便拭子。对提取的 DNA 进行鸟枪宏基因组测序，并评估粪便微生物群结构和 ARGs 的丰度。总的来说，猪粪便微生物群及其伴随的 ARG 是多样的，并且在出生后不久就建立起来。在所有样本中，共鉴定出与 19 种不同类别抗生素相关的 127 个 ARG。在实验组和所有时间点都观察到大多数已识别的 ARG。 TUL 和 CONT 组之间微生物组成和 ARG 丰度差异的幅度和程度在统计学上不显着。然而，粪便微生物群组成和 ARGs 丰度在不同采样日之间发生了显着变化。综上所述，这些结果表明，围产期 TUL 后备治疗对断奶前仔猪的粪便微生物群结构和 ARG 丰度没有可测量的益处或不利影响。

       While the antimicrobial resistance profiles of cultured pathogens have been characterized in swine, the fluctuations in antimicrobial resistance genes (ARGs) associated with the developing gastrointestinal microbiota have not been elucidated. The objective of this study was to assess the impact of perinatal tulathromycin (TUL) metaphylaxis on the developmental dynamics of fecal microbiota and their accompanying antimicrobial resistome in pre-weaned piglets. Sixteen litters were given one of two treatments [control group (CONT; saline 1cc IM) and TUL group (TUL; 2.5 mg/kg IM)] directly after birth. Deep fecal swabs were collected at day 0 (prior to treatment), and again at days 5 and 20 post treatment. Shotgun metagenomic sequencing was performed on the extracted DNA, and the fecal microbiota structure and abundance of ARGs were assessed. Collectively, the swine fecal microbiota and their accompanying ARGs were diverse and established soon after birth. Across all samples, a total of 127 ARGs related to 19 different classes of antibiotics were identified. The majority of identified ARGs were observed in both experimental groups and at all-time points. The magnitude and extent of differences in microbial composition and abundance of ARGs between the TUL and CONT groups were statistically insignificant. However, both fecal microbiota composition and ARGs abundance were changed significantly between different sampling days. In combination, these results indicate that the perinatal TUL metaphylaxis has no measurable benefits or detriment impacts on fecal microbiota structure and abundance of ARGs in pre-weaned piglets.

https://www.frontiersin.org/articles/10.3389/fmicb.2019.00726/full