The Occurrence and Distribution Pattern of Antibiotic Resistance Genes and Bacterial Community in the Ili River

Xiaobo Yang,Yutong Yang,Yang Cao,Hongrui Zhou,Jingfeng Wang,Shang Wang,Zhigang Qiu,Zhiqiang Shen,Li Yan,Chen Zhao,Chenyu Li,Bin Xue,Xi Zhang

doi:10.3389/fenvs.2022.840428

Xiaobo Yang, Yutong Yang + Show 11 more

Open Access

https://doi.org/10.3389/fenvs.2022.840428

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Abstract

The emergence of antibiotic resistance genes (ARGs) is a great risk to the ecosystem and human health; however, there are rare systematic studies about the characterization and source identification of ARGs in continental rivers. This study examined the occurrence of bacterial communities and ARGs in the water and soil of the Ili River using bacterial testing and metagenomic sequencing. Total dissolved solids (TDSs) and total bacterial count significantly increased from upstream to downstream sites. Enterococcus showed the highest abundance in Cockdara. Metagenomic sequencing revealed that the bacterial communities of surface water were different from those of nearshore soils. Among the top 10 ARGs, fluoroquinolone and aminoglycoside resistance genes exhibited dominant relative abundance, but only the multidrug resistance gene adeF was common in all water and soil samples. Proteobacteria carried almost 61% of ARGs, suggesting that these could be the main antibiotic-resistant bacteria (ARB) in the Ili River. Proteobacteria and ARB were mainly distributed in Yining city and Cockdara. Furthermore, the distribution pattern among the five sampling sites indicated that human activity and animal husbandry greatly contributed to the ARB and ARG contamination. This study first investigated the occurrence and distribution pattern of ARGs in the Ili River, demonstrating a clear correlation between bacteria and ARGs, and ARGs and mobile genetic elements (MGEs).

Highlights

Worldwide, deteriorating water quality has become a critical environmental problem, causing a great threat to human health, ecological biodiversity, and even social stability (Landrigan et al, 2020)
Enterococcus amounts ranged from 18 to 183 MPN/100 ml, and sampling sites BGC and Huiyuan city (HY) had the least amount of Enterococcus, followed by Yining city (YN), B219, and KKDL
After 24-h incubation of the supernatant, Coliform and Enterococcus faecalis were cultured from all five samples, and Staphylococcus aureus was found except for the BGC site (Table 2)

Summary

Introduction

Worldwide, deteriorating water quality has become a critical environmental problem, causing a great threat to human health, ecological biodiversity, and even social stability (Landrigan et al, 2020). The river system, a precious fundamental resource for living species, plays critical roles as was for drinking, agricultural irrigation, traffic channel, and recreational activities. The river system can be a pool of various pollutants, including physical, chemical, and biological pollutions (Hu et al, 2017). The pollution of surface water is the most severe environmental concern causing diseases (Landrigan et al, 2020). Several studies showed a close link between river water pollution and the increasing incidence of gastrointestinal diseases (Rodriguez-Tapia and Morales-Novelo, 2017), infectious diseases (Johnson et al, 2012), waterborne endemic fluorosis, and arsenic poisoning (Boelee et al, 2019; Karkman et al, 2019).

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