摘要
      牲畜粪便中含有高水平的抗生素抗性基因（ARGs）和多种与人类相关的病原体。利用甲虫Protaetia shortearsis的幼虫对牲畜粪便进行生物转化是减少废物和创造价值的有效技术；然而，粪便ARGs在肠道通过过程中的命运以及与P.britarsis肠道微生物组的相互作用仍不清楚。为了研究这一点，我们用干鸡粪喂养了P.britarsis 6天，并使用高通量定量PCR和宏基因组学方法测量了B.britarsis肠道中的细菌群落动态以及ARG丰度和多样性。幼虫中肠、后肠和粪便中ARGs的多样性显著低于生鸡粪，约80%的致病性相关基因（PRG）丰度降低。网络分析表明，拟杆菌门和厚壁菌门是与ARG减少相关的关键细菌门。宏基因组分析进一步表明，ARGs、可移动遗传元件（MGE）和PRG在后肠中同时减弱，这表明在粪肥生物转化过程中，细菌和病原体之间ARGs水平基因转移（HGT）的可能性降低。我们的研究结果表明，ARG的衰减与P.britarsis肠道微生物组的变化密切相关，这为粪肥生物转化过程中ARG传播的风险缓解机制提供了见解。
ABSTRACT
Livestock wastes contain high levels of antibiotic resistance genes (ARGs) and a variety of human-related pathogens. Bioconversion of livestock manure using larvae of the beetle Protaetia brevitarsis is an effective technique for waste reduction and value creation; however, the fate of manure ARGs during gut passage and interaction with the gut microbiome of P. brevitarsis remains unclear. To investigate this, we fed P. brevitarsis with dry chicken manure for 6 days and measured bacterial community dynamics and ARG abundance and diversity along the P. brevitarsis gut tract using high-throughput quantitative PCR and metagenomics approaches. The diversity of ARGs was significantly lower in larval midgut, hindgut, and frass than in raw chicken manure, and around 80% of pathogenicity-related genes (PRGs) exhibited reduced abundance. Network analysis demonstrated that Bacteroidetes and Firmicutes were the key bacterial phyla associated with ARG reduction. Metagenomic analysis further indicated that ARGs, mobile genetic elements (MGEs), and PRGs were simultaneously attenuated in the hindgut, implicating a decreased likelihood for horizontal gene transfer (HGT) of ARGs among bacteria and pathogens during manure bioconversion. Our findings demonstrated that the attenuation of ARGs is strongly associated with the variation of the gut microbiome of P. brevitarsis, providing insights into mechanisms of risk mitigation of ARG dissemination during manure bioconversion.

https://journals.asm.org/doi/full/10.1128/msystems.00529-22