RESUMO
Nanomaterials of Al2O3 and TiO2 have been proved to promote the spread of antibiotic resistance genes (ARGs) by horizontal gene transfer. In this work, we found that Fe2O3@MoS2 nanocomposite inhibited the horizontal gene transfer (HGT) by inhibiting the conjugative transfer mediated by RP4-7 plasmid. To discover the mechanism of Fe2O3@MoS2 inhibiting HGT, the bacterial cells were collected under the optimal mating conditions. The collected bacterial cells were used for analyzing the expression levels of genes unique to the plasmid and the bacterial chromosome in the conjugation system by qPCR. The results of genes expression demonstrated that the mechanism of Fe2O3@MoS2 inhibited conjugation by promoting the expression of global regulatory gene (trbA) and inhibiting the expression of conjugative transfer genes involved in mating pair formation (traF, trbB) and DNA replication (trfA). The risk assessment of Fe2O3@MoS2 showed that it had very low toxicity to organisms. The findings of this paper showed that Fe2O3@MoS2, as an inhibitor of horizontal gene transfer, is an environment-friendly material.
Assuntos
Conjugação Genética/efeitos dos fármacos , Dissulfetos/química , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Compostos Férricos/química , Transferência Genética Horizontal/efeitos dos fármacos , Molibdênio/química , Nanocompostos/química , Antibacterianos/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/genética , Conjugação Genética/genética , Dissulfetos/farmacologia , Resistência Microbiana a Medicamentos/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Compostos Férricos/farmacologia , Genes Microbianos , Molibdênio/farmacologia , Plasmídeos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genéticaRESUMO
In this study, we found that Fe3O4 promoted horizontal gene transfer (HGT), but when Fe3O4 was composited with MoS2, the Fe3O4@MoS2 nanocomposite interacting with bacteria significantly blocked the HGT in the conjugation system. qPCR was used to analyze the expression of genes belonging to the chromosome and plasmid in the conjugation system. Results demonstrated that Fe3O4@MoS2 inhibited conjugation by promoting the expression of the global regulatory gene (trbA) and inhibiting the expression of conjugative transfer genes involved in mating pair formation (traF, trbB), DNA replication (trfA), and porins (outer membrane protein (omp) A and ompC). All of these genes are related to the permeability of the cell membrane, except for trfA. The results showed that Fe3O4@MoS2 interacted with bacteria to decrease their permeability against exogenous DNA. MoS2 may play an essential role in the HGT-inhibiting activity of Fe3O4@MoS2. This study highlights the diverse biological properties of nano-materials and provides clues for nano-scientists to develop environmentally friendly materials.