摘要
      畜禽粪便是储存和传播抗生素抗性基因（ARGs）的主要载体。本研究的目的是确定导致ARGs和MGE相对丰度变化的关键环境因素，以探索减少ARGs发生的有效方法。在CM和PM好氧堆肥中，使用0、3、7、10、14、21、28、45、60和75d的实时定量PCR测量了10个ARG和5个MGE的丰度。利用16S rRNA高通量测序分析了细菌群落的演替规律。此外，ARGs和MGE的丰度与堆肥堆的性质（温度、含水量、pH和DOC）相关，以确定影响ARGs或MGE变化的关键因素。结果表明，PM中ARGs和MGE的丰度高于CM。堆肥显著降低了9种ARGs的相对丰度和5种MGE的相对丰度。CM中三种ARGs（tetM、tetT和aacA）和四种MGE（ISEcp1、IS1216、IS613和tnp614）的去除率达到99%。9种ARG[tetB（P）、tetL、tetM、tetO、tetT、aacA、aadD、aphA3和sat4]和4种MGE（ISEcp1、IS26、IS1216和tnp614）在PM中的去除率达到99%。然而，基因tetG、intI1和IS6100的丰度增加。在堆肥过程中，厚壁菌门和放线菌门在CM和PM中占主导地位。放线菌和变形菌可能是tetG和intI1的主要宿主菌。冗余分析表明，水分和pH是影响ARGs和MGEs丰度差异的关键因素。ARGs的组成和丰度由理化性质、细菌群落和MGE驱动。堆肥可以显著降低CM和PM中ARGs的丰度，从而降低ARGs通过施用牲畜粪便分布的风险。然而，一些ARG和MGE的丰度仍然很高。因此，有必要进一步优化堆肥工艺，提高畜禽粪便的无害化处理效果，促进有机肥料的安全农业使用。
Abstract 
Livestock manure is a major carrier that stores and transmits antibiotic resistance genes (ARGs). The aim of this study was to identify the crucial environmental factors that result in the change in relative abundance of ARGs and MGEs to explore effective methods to reduce the occurrence of ARGs. The abundance of ten ARGs and five MGEs were measured using real-time quantitative PCR with 0, 3, 7, 10, 14, 21, 28, 45, 60, and 75 d in CM and PM aerobic composting. The succession law of the bacterial community was analyzed using 16S rRNA high-throughput sequencing. Furthermore, the abundance of ARGs and MGEs was correlated with the properties (temperature, moisture content, pH, and DOC) of composting piles to identify the crucial factors affecting the variation in ARGs and MGEs. The results showed that the abundance of ARGs and MGEs in PM was higher than that in CM. Composting significantly reduced the relative abundance of nine ARGs and five MGEs. The removal ratios of three ARGs (tetM, tetT, and aacA) and four MGEs (ISEcp1, IS1216, IS613, and tnp614) in CM reached 99%. The removal ratios of nine ARGs[tetB(P), tetL, tetM, tetO, tetT, aacA, aadD,aphA3, and sat4] and four MGEs (ISEcp1, IS26, IS1216, and tnp614) reached 99% in PM. However, the abundance of the genes tetG, intI1, and IS6100 increased. Firmicutes and Actinobacteria were dominant in CM and PM during composting. Actinobacteria and Proteobacteria may have been the major host bacteria of tetG and intI1. The redundancy analysis showed that moisture and pH were the crucial factors that could influence the differences in the abundance of ARGs and MGEs. The composition and abundance of ARGs were driven by physicochemical properties, bacterial community, and MGEs. Composting could significantly reduce the abundance of ARGs in CM and PM, thus reducing the risk of ARGs being distributed via livestock manure application. However, some ARGs and MGEs remained in high abundance. Therefore, it is necessary to further optimize the composting process, improve the harmless treatment effect of livestock manure, and promote the safe agricultural use of organic fertilizers.

https://europepmc.org/article/med/36922238