Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China.
College of Life Sciences, Langfang Normal University, Langfang, China.
Environ Pollut. 2024 Nov 15;361:124851. doi: 10.1016/j.envpol.2024.124851. Epub 2024 Aug 30.
Conjugative plasmids are important vectors of mobile antibiotic resvistance genes (ARGs), facilitating their horizontal transfer within the environment. While composting is recognized as an effective method to reduce antibiotics and ARGs in animal manure, its impact on the bacterial host communities containing antibiotic-resistant plasmids remains unclear. In this study, we investigated the permissiveness of bacterial community during composting when challenged with multidrug-resistant conjugative RP4 plasmids, employing Pseudomonas putida as the donor strain. Ultimately, this represents the first exploration of the effects of aeration rates on the range of RP4 plasmid transfer hosts. Transconjugants were analyzed through fluorescent reporter gene-based fluorescence-activated cell sorting and Illumina sequencing. Overall, aeration rates were found to influence various physicochemical parameters of compost, including temperature, pH, total organic matter, total nitrogen, and potassium. Regarding RP4 plasmid host bacteria, the dominant phylum was determined to shift from Bacteroidetes in the raw material to Proteobacteria in the compost. Notably, a moderate-intensity aeration rate (0.05 L/min/L) was found to be more effective in reducing the diversity and richness of the RP4 plasmid host bacterial community. Following composting, the total percentage of dominant transconjugant-related genera decreased by 66.15-76.62%. Ultimately, this study determined that the aeration rate negatively impacts RP4 plasmid host abundance primarily through alterations to the environmental factors during composting. In summary, these findings enhance our understanding of plasmid host bacterial communities under varying composting aeration rates and offer novel insights into preventing the dissemination of ARGs from animal manure to farmland.
共轭质粒是移动抗生素抗性基因 (ARGs) 的重要载体，促进了它们在环境中的水平转移。虽然堆肥被认为是减少动物粪便中抗生素和 ARGs 的有效方法，但它对抗生素抗性质粒的细菌宿主群落的影响尚不清楚。在这项研究中，我们研究了在多药耐药性共轭 RP4 质粒挑战下，细菌群落在堆肥过程中的宽容性，使用 Pseudomonas putida 作为供体菌株。最终，这代表了首次探索通气率对 RP4 质粒转移宿主范围的影响。通过基于荧光报告基因的荧光激活细胞分选和 Illumina 测序分析转导体。总体而言，通气率被发现会影响堆肥的各种物理化学参数，包括温度、pH 值、总有机物、总氮和钾。关于 RP4 质粒宿主细菌，优势门从原料中的拟杆菌门转变为堆肥中的变形菌门。值得注意的是，中等强度的通气率（0.05 L/min/L）被发现更有效地降低 RP4 质粒宿主细菌群落的多样性和丰富度。堆肥后，主要转导体相关属的总百分比下降了 66.15-76.62%。最终，本研究确定通气率主要通过改变堆肥过程中的环境因素对 RP4 质粒宿主丰度产生负面影响。总之，这些发现增强了我们对不同堆肥通气率下质粒宿主细菌群落的理解，并为防止 ARGs 从动物粪便传播到农田提供了新的见解。
