We studied the distribution and conjugation efficiency of the multidrug-resistant conjugative plasmid in Haihe River based on the receptor labelled with fluorescent protein. In addition, we quantified the 29 ARGs in Haihe River by qPCR. The result showed that there are 202 conjugants and 26 conjugative plasmids obtained from 11 sediments collected in the Haihe River (72 km). Plasmids isolated from the urban areas of Haihe River have higher transfer frequency than the rural areas. The results showed that there was a close relationship between the conjugation plasmid and the abundance of ARGs in Haihe River by plasmids sequencing. The blaIMI-3 gene was located in the ISE36 harbored by the plasmid pGA45, which is highly homologous to the sequence of Ecoli W365 and plasmid PT103, indicating that the conjugative transfer of multi-resistant plasmids contributes to the dissemination and propagation of ARGs in Haihe River. The conjugative transfer of multi-resistant plasmids was significantly increased under stress of chemicals. Nanoparticles potentially facilitate the horizontal transfer of ARGs was further investigated. 10 mg/L of nZnO significantly increased the conjugative frequency of antibiotic resistance plasmid RP4 in E. coli pure cultures (24.3 fold) and in aquatic microbiota (8.3 fold), suggesting that a variety of bacterial genera could serve as the recipient of plasmid RP4 in the environment. Furthermore, 1 mg/L nZnO can increase the transformation efficiency (3 fold) of E. coli, which was confirmed by confocal fluorescence microscopy. Enhanced horizontal transfer of resistance plasmids was a nanoparticle-specific effect. We further confirmed that the horizontal gene transfer was attributed to increased bacterial cell permeability after exposure to nZnO. Overall, our study showed that the conjugative multi-resistant plasmid contributed to the dissemination and propagation of ARGs in Haihe River and nanoparticles released to the environment will facilitate dissemination and propagation of ARGs through horizontal gene transfer.

Dissemination and propagation of ARGs mediated by conjugative multi-resistant plasmids

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.