Potential dissemination mechanism of the tetC gene in Aeromonas media from the aerobic biofilm reactor under oxytetracycline stresses  

作　　者：Yanhong Shi Yu Zhang Xiangyang Wu Hong Zhang Min Yang Zhe Tian 

机构地区：[1]School of the Environment and Safety Engineering,Jiangsu University,Zhenjiang 212013,China [2]State Key Laboratory of Environmental Aquatic Chemistry,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China

出　　处：《Journal of Environmental Sciences》2021年第7期90-99,共10页环境科学学报（英文版）

基　　金：supported by the Project of International Cooperation and Exchanges NSFC(No.31861143049);the National Natural Scientific Foundation of China(Nos.51978645,21437005);the China Postdoctoral Science Foundation(No.2019M661756).

摘　　要：The tet C gene has been found to be one of the most widely distributed tetracycline resistance( tet) genes in various environmental niches, but the detailed dissemination mechanisms are still largely unknown. In the present study, 11 tet C-containing Aeromonas media strains were isolated from an aerobic biofilm reactor under oxytetracycline stresses, and the genome of one strain was sequenced using the Pac Bio RSII sequencing approach to reveal the genetic environment of tet C. The tet C gene was carried by an IS 26 composite transposon, named Tn 6434. The tet C-carrying Tn 6434 structure was detected in all of the A. media strains either in a novel plasmid p Aeme2( n = 9) or other DNA molecules( n = 2) by PCR screening. The NCBI database searching result shows that this structure was also present in the plasmids or chromosomes of other 13 genera, indicating the transferability of Tn 6434. Inverse PCR and sequencing confirmed that Tn 6434 can form a circular intermediate and is able to incorporate into a preexisting IS 26 element, suggesting that Tn 6434 might be responsible for the dissemination of tet C between different DNA molecules. This study will be helpful in uncovering the spread mechanism of tet genes in water environments.

关 键 词：Aeromonas media TETC IS 26 Circular intermediate Inverse PCR 

分 类 号：X172[环境科学与工程—环境科学]