Homogeneous selection drives antibiotic resistome in two adjacent sub-watersheds, China

The Effect of the Effluent from a Small-Scale Conventional Wastewater Treatment Plant Treating Municipal Wastewater on the Composition and Abundance of the Microbial Community, Antibiotic Resistome, and Pathogens in the Sediment and Water of a Receiving Stream

“…In general, the ARG abundances in water decreased along the distance gradient further downstream, and the WWTP effluent-associated sul1-sul2-aadA-blaOXA2 cluster became virtually undetectable (except for a minute amount of sul1 genes) from the 2.7 km location onward. The decrease of ARGs in stream water across a distance gradient from WWTP discharge has also been reported by other studies [33,37,42]. In the sediments, the changes in the structure of the resistome along a distance gradient indicated recovery from the impact of WWTP effluent as the proportions of sulfonamide, aminoglycoside, and betalactam resistance, as well as the of sul1-sul2-aadA-blaOXA2 cluster, gradually decreased, and in the river sediments 3.7 km downstream of WWTP, the resistome was remarkably similar to the resistome of the stream sediments upstream of the WWTP.…”

“…Even though the proportion of antibiotic resistome in the microbial communities of water and sediments preceding and following the WWTP discharge point remained virtually unchanged, shifts in resistome structure towards an increase in resistance types prevalent in WWTP effluent, as well as a higher number of detected ARG subtypes and generally increased ARG abundances 0.3 km downstream in water and sediment were recorded. In this location, elevated proportions of sulfonamide and aminoglycoside resistance types, and more specifically, sul1, sul2, and aadA, as well as, to a lesser extent, beta-lactam-resistance-encoding blaOXA genes, reported as characteristic of heavily impacted waterbodies [41,42], were recorded in the water and sediment. Upstream of WWTP, as well as in the river upstream of stream inflow, the abundances of these ARGs were low in the sediments and nondetectable in water, indicating a low anthropogenic impact in these locations and suggesting that the WWTP effluent can be a predominant source of ARGs.…”

Utilizing Metagenomic Data and Bioinformatic Tools for Elucidating Antibiotic Resistance Genes in Environment

“…Specifically, among these source-tracking tools, some including SourceTracker and MST can be used to precisely track ARG pollution from different sources. For example, based on deep-sequencing marker genes, such as 16S rRNA, SourceTracker was designed and constructed with a Bayesian classification model; this tool uses Gibbs sampling to determine the possibility and predict the source of samples (Knights et al, 2011) and has been widely applied to determine the source of ARG pollution in diverse environment samples (Hu et al, 2020;Chen et al, 2019c). Moreover, on the basis of a machine-learning classification strategy with ARG abundance profiles, MST was developed and constructed as a source-tracking platform that can precisely track ARG pollution from different sources, such as feces of humans and animals, wastewater treatment plants, and other natural environments (Li et al, 2018;Li et al, 2020), which is available at https://smile.hku.…”

A Comprehensive Profile of Antibiotic Resistance Genes in the Water Column of a Shallow-Sea Hydrothermal Vent Ecosystem

“…The World Health Organization estimated that antimicrobial resistance-induced diseases will cause more than 10 million deaths per year by 2050 [5]. The application of high-throughput molecular technologies in recent years, such as shotgun metagenomic sequencing and high-throughput quantitative PCR (HT-qPCR), significantly enhance our ability to get a comprehensive profile of an antibiotic resistome in various environments, but also identify the associated regulating factors [6][7][8][9][10]. Mounting evidence suggests that the biotic processes, including the vertical genetic transfer (VGT) and horizontal genetic transfer (HGT), are the primary mechanisms controlling the proliferation and dissemination of ARGs [11].…”

“…In addition, abiotic factors, such as chemical pollutants (non-antibiotic pharmaceuticals and metalloids etc. ), may cause the spread of ARGs through the promotion of the HGT or co-selection processes [8,11]. Although a plethora of studies have revealed the biogeographic distribution of ARGs in various anthropogenicdisturbed environments [20][21][22][23], there is limited information about the ARG profiles in pristine habitats, especially for the shallow-sea hydrothermal vents, which is essential for defining the baseline level of environmental ARGs.…”