引言：农田中的微生物污染通常被低估和研究不足。不同的施肥时间和粪肥来源可能会引入和改变农田土壤中的微生物多样性，从而影响微生物污染的丰度和持久性，包括抗生素抗性基因（ARGs）、人类细菌病原体（HBPs）和毒力因子基因（VFGs）。
方法：进行0.5-1.5年的受精实验，并进行宏基因组测序以量化微生物污染。土壤样品的耐药性表明，在兽医学中广泛使用的抗抗生素ARGs以及临床关键ARGs（CCARGs）在粪肥改良土壤中持续存在。本文选择超广谱β-内酰胺酶和碳青霉烯酶bla基因、高水平动员粘菌素抗性基因mcr、替加环素抗性基因tet（X）和万古霉素抗性基因van，所有这些都可以绕过这些“最后手段”抗生素的防线，来调查农场环境中的CCARG污染。
结果：在土壤样品中共检测到254个潜在HBP和2106个VFG。总的来说，我们的研究结果表明：（1）农田土壤可以作为一些重要的bla、mcr、tet（X）和van基因变体的库，（2）HBPs和VFG的多样性和相对丰度随着施肥时间的增加而显著增加，并且在不同施肥土壤之间存在差异，（3）大多数CCARGs和VFG共存于HBPs中。
异议：本研究结果表明，粪肥在传播抗微生物耐药性和致病性方面存在生物学风险。
Introduction: Microbial contamination in farmlands is usually underestimated and understudied. Different fertilization times and manure origins might introduce and change the microorganism diversity in farmland soils and thus might influence the abundance and persistence of microbial contamination including antibiotic resistance genes (ARGs), human bacterial pathogens (HBPs), and virulence factor genes (VFGs).

Methods: A 0.5-/1.5-year fertilization experiment was performed, and metagenomic sequencing was conducted to quantify microbial contamination. The resistomes of soil samples revealed that ARGs against antibiotics which were extensively used in veterinary medicine as well as clinically critical ARGs (CCARGs) persisted in manure-amended soils. Here the extended-spectrum beta-lactamase and carbapenemase bla genes, the high-level mobilized colistin resistance gene mcr, the tigecycline resistance gene tet(X), and the vancomycin resistance gene van, all of which can circumvent the defense line of these “last-resort” antibiotics were selected to investigate CCARG pollution in farm environments.

Results: A total of 254 potential HBPs and 2106 VFGs were detected in soil samples. Overall, our results revealed that (1) farmland soils could serve as a reservoir of some important bla, mcr, tet(X), and van gene variants, (2) the diversity and relative abundance of HBPs and VFGs increased significantly with incremental fertilization times and were discrepant among different manureamended soils, and (3) most CCARGs and VFGs coexisted in HBPs.

Disscusion: The results of this study suggested a biological risk of manure in spreading antimicrobial resistance and pathogenicity.

https://www.frontiersin.org/articles/10.3389/fcimb.2022.1073118/full?utm_source=dlvr.it&utm_medium=twitter