Cadmium enhances conjugative plasmid transfer to a fresh water microbial community. (1st January 2021)

• Record Type: Journal Article
• Authors: Pu, Qiang; Fan, Xiao-Ting; Li, Hu; An, Xin-Li; Lassen, Simon Bo; Su, Jian-Qiang
• Is Part Of: Environmental pollution. Volume 268(2021)Part B
• Publication Date: 2021-01-01
• Subjects: Heavy metal -- Horizontal transfer -- ARGs -- Pseudomonas putida; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.115903
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Co-selection of antibiotic resistance genes (ARGs) by heavy metals might facilitate the spread of ARGs in the environments. Cadmium contamination is ubiquitous, while, it remains unknown the extent to which cadmium (Cd 2+ ) impact plasmid-mediated transfer of ARGs in aquatic bacterial communities. In the present study, we found that Cd 2+ amendment at sub-inhibitory concentration significantly increased conjugation frequency of RP4 plasmid from Pseudomonas putida KT2442 to a fresh water microbial community by liquid mating method. Cd 2+ treatment (1–100 mg/L) significantly increased the cell membrane permeability and antioxidant activities of conjugation mixtures. Amendments of 10 and 100 mg/L Cd 2+ significantly enhanced the mRNA expression levels of mating pair formation gene ( trb Bp) and the DNA transfer and replication gene ( trf Ap) due to the repression of regulatory genes ( kor A, kor B and trb A). Phylogenetic analysis of transconjugants indicated that Proteobacteria was the dominant recipients and high concentration of Cd 2+ treatment resulted in expanded recipient taxa. This study suggested that sub-inhibitory Cd 2+ contamination would facilitate plasmid conjugation and contributed to the maintenance and spread of plasmid associated ARGs, and highlighted the urgent need for effective remediation of Cd 2+ in aquatic environments. Graphical abstract: Image 1 Highlights: Cd 2+ amendment significantly increase conjugative transfer of plasmid-borne ARGs. High Cd 2+ levels increase cell membrane permeability and antioxidant activities. High Cd 2+ levels promote RP4 transfer by regulating conjugation genes expression. High concentration of Cd 2+ promotes RP4 plasmid transfer to more bacterial species.