Nano-alumina Promotes the Horizontal Transfer of the Multiresistance Plasmid Cross-genus: from Escherichia coli to Salmonella sp

摘要

Antibiotic resistance has become a worldwide public health concern. Conjugative transfer between closely related strains or species is an important method for the horizontal transfer of multiresistance genes. Alumina plays an important role in the regulation of the composition of soil water,sediment water,and other natural water systems. Nano-alumina,due to its huge surface area,has several applications in this field as an adsorbent and a catalyst. However,the extent to which nanomaterials are able to bring about an increase in antibiotic resistance by regulating the conjugative transfer of antibiotic resistance genes in bacteria,especially cross-genus is still unknown. Here we have shown that nano-alumina in water significantly promotes the horizontal conjugative transfer frequency of multiresistance genes by up to 100-fold from E. coli to Salmonella spp.. We also explored the mechanisms behind this phenomenon and demonstrated that nano-alumina is able to induce oxidative stress,cause the damage of bacterial cell membranes,enhance the expression of conjugative gene,and depress the expression of global regulatory factor genes that transfer drug resistance. These findings are important in the assessment of nanomaterials risk to the environment,particularly from water and wastewater treatment systems and the manufacture and use of nanomaterials in the environment.