Zhou Guo-Wei, Zheng Fei, Fan Xiao-Ting, Li Ming-Jun, Sun Qing-Ye, Zhu Yong-Guan, Yang Xiao-Ru
School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China; Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; School of Life Sciences, Hebei University, Baoding 071002, China.
J Hazard Mater. 2022 Feb 15;424(Pt B):127525. doi: 10.1016/j.jhazmat.2021.127525. Epub 2021 Oct 16.
Plasmid conjugation contributes greatly to the spread of antibiotic resistance genes (ARGs) in soils. However, the spread potential in the gut of soil fauna remains poorly studied, and little was known about the impact of host age on ARGs dissemination in the gut microbiota of soil animals. Here, the typical nematode-Caenorhabditis elegans was employed as the model soil animal, aiming to investigate transfer of broad-host-range IncP-1ɛ from Escherichia coli MG1655 to gut microbiota within 6 days under varied temperature gradients (15, 20 and 25 °C) using qPCR combined with plate screening. Results showed that conjugation rates increased with incubation time and rising temperature in the gut of C. elegans, sharing a similar trend with abundances of plasmid conjugation relevant genes such as trbBp (mating pair formation) and trfAp (plasmid replication). Incubation time and temperature significantly shaped the gut microbial community of C. elegans. Core microbiota in the gut of C. elegans, including Enterobacteriaceae, Lactobacillaceae and Leuconostocaceae, constituted a large part of transconjugal pool for plasmid IncP-1ɛ. Our results highlight an important sink of gut microbiota for ARGs dissemination and upregulation of ARGs transfer in the gut microbiota with host age, further potentially stimulating evolution of ARGs in terrestrial environments.
质粒接合作用对土壤中抗生素抗性基因（ARGs）的传播有很大贡献。然而，其在土壤动物肠道中的传播潜力仍研究不足，而且宿主年龄对土壤动物肠道微生物群中ARGs传播的影响也知之甚少。在此，以典型的线虫——秀丽隐杆线虫作为模式土壤动物，旨在通过定量聚合酶链反应（qPCR）结合平板筛选，研究在不同温度梯度（15、20和25°C）下，广宿主范围的IncP-1ɛ质粒从大肠杆菌MG1655转移至肠道微生物群的情况，时间跨度为6天。结果表明，在秀丽隐杆线虫肠道中，接合率随孵育时间和温度升高而增加，这与质粒接合相关基因如trbBp（配对形成）和trfAp（质粒复制）的丰度变化趋势相似。孵育时间和温度显著影响了秀丽隐杆线虫的肠道微生物群落。秀丽隐杆线虫肠道中的核心微生物群，包括肠杆菌科、乳杆菌科和明串珠菌科，构成了质粒IncP-1ɛ转接合体库的很大一部分。我们的研究结果突出了肠道微生物群在ARGs传播中的重要作用，以及随着宿主年龄增长ARGs在肠道微生物群中转移的上调，这可能进一步刺激陆地环境中ARGs的进化。
