Distribution Characteristics of Antibiotic Resistance Genes on Different Water Supply Pipes

Abstract

To study the distribution characteristics and horizontal transfer potential of antibiotic resistance genes in biofilms of water supply pipes made of different materials, the biofilms of 304 and 316 L stainless steel pipes and PPR and PE plastic pipes were analyzed using metagenomic sequencing. The results showed that a total of 146 antibiotic resistance genes belonging to 17 classes were detected in the biofilms. Multidrug resistance genes had the highest abundance and varied a lot in different biofilms, which was the main reason for the differences in antibiotic resistance genes in different biofilms. The total abundance of mobile genetic elements was high in different biofilms, but overall coexistence with antibiotic resistance genes was low, with integrase genes showing a closer relationship with antibiotic resistance genes and possibly playing an important role in the horizontal transfer of antibiotic resistance genes. Different antibiotic resistance genes possessed different genera of potential hosts; highly abundant hosts such as Aquabacterium and Bradyrhizobium were the basis for the presence of a high abundance of multidrug resistance genes. Microbial attachment in different pipe walls was selective, and the primary influence of antibiotic resistance in biofilms was bacterial community composition, followed by the horizontal transfer of genes mediated by mobile genetic elements, community composition, and mobile genetic elements together shaping the distribution characteristics of antibiotic resistance genes.