Details

Autor(en) / Beteiligte

• Li, Wen
• Zhang, Wei-Guo
• Zhang, Ming-Sha
• Lei, Zhong-Fang
• Li, Peng-Fu
• Ma, Yan
• Gao, Yan

Titel

Environmentally relevant concentrations of mercury facilitate the horizontal transfer of plasmid-mediated antibiotic resistance genes

Ist Teil von

• The Science of the total environment, 2022-12, Vol.852, p.158272-158272, Article 158272

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2022

Quelle

Elsevier ScienceDirect Journals

Beschreibungen/Notizen

• Abundant antibiotic resistance genes (ARGs) are typically found in mercury (Hg)-contaminated aquatic environments. This phenomenon is partly attributed to the co-resistance, cross-resistance, and shared regulatory responses to Hg and antibiotics. However, it remains unclear whether and how Hg influences the conjugative transfer of ARGs mediated by mobilizable plasmids. In the present study, we found that Hg2+ at the environmentally relevant concentrations (0.001–0.5 mg L−1) facilitated the conjugative transfer of ARGs through the mobilizable plasmid RP4 from the donor Escherichia coli HB101 to the recipient E. coli K12. Exposure to Hg2+ significantly increases the formation of reactive oxygen species, malondialdehyde production, antioxidant enzyme activities, and cell membrane permeability, while decreasing the concentration of glutathione. Scanning electron microscopy and transmission electron microscopy showed that the cell membrane suffered from oxidative damage, which is beneficial for conjugative transfer. The expression of global regulatory genes (korA, korB, and trbA) negatively regulating conjugative transfer was restrained by Hg2+, while promoting the expression of positive regulatory genes involved in the mating pair formation system (trbBp and traF) and the DNA transfer and replication systems (trfAp and traJ). Although a high Hg2+ concentration (1.0 mg L−1) suppressed ARGs conjugative transfer, our results suggest that Hg2+ facilitates the dissemination of ARGs in aquatic environments at environmentally relevant concentrations. This study improves our understanding of ARGs dissemination in Hg-contaminated aquatic environments. [Display omitted] •Environmentally relevant concentrations of Hg2+ facilitated ARGs conjugative transfer.•A high Hg2+ concentration suppressed ARGs conjugative transfer.•Exposure of Hg2+ disturbed the cellular oxidative and antioxidative systems.•Hg2+ strongly influenced the expressions of genes involved in ARGs conjugative transfer.