生态环境学报2023，Vol.32Issue(11)：1978-1987,10.DOI:10.16258/j.cnki.1674-5906.2023.11.008
土壤环境中四环素抗性基因向病原菌的转移研究
Transfer of Tetracycline Resistance Gene to Human Pathogenic Bacteria in Soil
摘要
Abstract
Antibiotic resistance genes(ARGs)have been recognized as new pollutants in the environment.Horizontal gene transfer(HGT)is the main way of ARGs transmission and diffusion.The horizontal transfer of ARGs in pure culture system has been reported,and the molecular mechanism of HGT has also been fully explored.However,whether ARGs in the environment can be captured by human pathogenic bacteria under natural conditions is still unknown.In order to investigate whether Salmonella can obtain ARGs from manure-amended soil under natural conditions and survive in soil for a long time,this study applied manure containing a large amount of tetracycline sensitive Salmonella to three types of soil,and treated the soils with or without flooding.After 90 days,tetracycline resistant Salmonella was isolated using selective medium containing tetracycline.The results showed that Salmonella in these soils did not obtain tetracycline resistance gene and survived in the soil for more than 90 days.Three suspected Salmonella strains resistant to tetracycline were isolated from the red clay soil,but they were identified as H2S producing Escherichia coli by physiological and biochemical analysis as well as 16S sequencing.They all carried multiple ARGs detected by HT-qPCR.Among the three strains,T2 carried the most ARGs,so the whole genome of T2 was sequenced and analyzed.The results showed that T2 carried an IncX1 type plasmid with a length of 40.48 kb and an IncY type plasmid with a length of 93.31 kb,15 gene islands,and 3807 injection-release genes which were annotated by COG database,including 197 prophages and transposons.A total of 34 ARGs were obtained through the ARDB annotation,including two tetracycline resistance genes located on the IncY type plasmid.By co-culturing T2 with tetracycline sensitive E.coli O157:H7 and applying different concentrations of tetracycline,the tetracycline resistance gene carried by T2 did not transfer to O157 strain.To sum up,it is rare for Salmonella to obtain ARGs from soil or manure in natural environment,and it is also difficult for the resistant E.coli T2 isolated from soil environment to transfer its tetracycline resistance genes to E.coli O157:H7 in pure culture system.These results can provide reference for scientific assessment of the transfer risk of ARGs in soil environment.关键词
抗生素抗性基因/沙门氏菌/细菌全基因组测序/基因转移Key words
Antibiotic resistance gene/Salmonella/Whole bacterial genome sequencing/Horizontal gene transfer分类
资源环境引用本文复制引用
彭双,宋丹,王一明,林先贵..土壤环境中四环素抗性基因向病原菌的转移研究[J].生态环境学报,2023,32(11):1978-1987,10.基金项目
江苏省自然科学基金面上项目(BK20201110) （BK20201110）
内蒙古自治区科技重大专项(NMKJXM202009) （NMKJXM202009）
国家重点研发计划项目(2021YFD1900602) （2021YFD1900602）
江苏省高校自然科学基金项目(18KJB210002) （18KJB210002）
江苏开放大学预研项目(19-GY-01) （19-GY-01）
江苏高校'青蓝工程'优秀骨干教师项目 （）
