Freshwater ecosystems offer natural settings for the proliferation and dissemination of bacteria and antibiotic resistance genes (ARGs). However, the biogeographical patterns of ARGs in natural freshwaters and their relationships with the bacterial community at large scales are largely understudied. This is of specific importance because data on ARGs in environments with low anthropogenic impact is still very limited.
A recent study by scientists from the Chinese Academy of Sciences characterized the biogeographical patterns of bacterial communities and their ARG profiles in inland waters of southeast China under low-anthropogenic impact at a large scale. They investigated the biogeographical patterns of bacterial communities and their ARG profiles in 24 reservoirs across southeast China along a distance gradient of 1800 km.
It was found that the composition of both bacterial communities– antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs)- exhibited a significant distance-decay pattern. ARG profiles showed greater variances than bacterial populations amongst various water bodies, and there was little correlation between bacterial communities and ARG profiles.
The stochastic and deterministic processes simultaneously drive the biogeographical patterns of bacterial communities, whereas the stochastic processes don’t explain the ARG profiles. This signifies a decoupling of bacterial community composition and ARG profiles in inland waters under relatively low-human impact at a large scale.
Professor YANG Jun from the Institute of Urban Environment (IUE) of the Chinese Academy of Sciences said, “This study improved our understanding of ARG distribution in inland waters with emphasis on drinking water supply reservoirs, therefore providing the much-needed baseline information for future monitoring and risk assessment of ARGs in drinking water resources.”