Bacterial Hosts and Genetic Characteristics of Antibiotic Resistance Genes in Wastewater Treatment Plants of Xinjiang (China) Revealed by Metagenomics

Abstract

Antibiotic resistance genes (ARGs) pose a widespread concern for human health and wastewater treatment plants (WWTPs) are considered to be a major source of ARG transmission. In this paper, the potential hosts and genetic characteristics of ARGs in the influent, activated sludge and effluent of WWTPs in Xinjiang were studied by metagenomics. Bacitracin resistance gene (bacA), beta-lactamase gene (class A beta-lactamase), multidrug resistance genes (mexD, qacEdelta1), and sulfonamide resistance genes (sul1, and sul2) are persistent antibiotic resistance genes (PARGs). The potential hosts of ARGs were mainly pathogens, with Escherichia coli (12.9%), Acinetobacter johnsonii (8.94%), and Klebsiella pneumoniae (5.30%) accounting for the highest proportions. Chromosomal sequences and plasmid sequences accounted for 42.0% and 22.6% of ARG-carrying contigs (ACCs) in the influent, respectively. Meanwhile, the effluent contained 58.3% of ACCs in plasmids and 8.30% in chromosomes. Bacitracin resistance genes and multidrug resistance genes were mainly carried by chromosomes, while resistance genes for macrolide–lincosamide–streptogramin (MLS), vancomycin, sulfonamide, beta-lactam, tetracycline, chloramphenicol, and aminoglycoside were mainly carried by plasmids. ICEPae690-sul1-qacEdelta1 and ICEPmiChn3-sul2 were stable coexistence structures and heighten the transfer potential of ARGs in the environment. This study provided a clearer picture of host bacterial sources and genetic context of ARGs in the environment.

Sensitivity and consistency of long- and short-read metagenomics and epicPCR for the detection of antibiotic resistance genes and their bacterial hosts in wastewater

“…Proteobacteria was the dominant host phylum for ARGs across the entire wastewater treatment process (Fig. 2d), which is consistent with previous studies [70][71][72] . Our results indicate that the shift in the microbial community, and specifically the growth and decay of certain phyla drove changes in the resistome across the WWTP (Fig.…”

Metagenomic Insight into Microbiome and Antibiotic Resistance Genes of High Clinical Concern in Urban and Rural Hospital Wastewater of Northern India Origin: a Major Reservoir of Antimicrobial Resistance

“…Exploring the bacterial host of an ARG is a crucial question to be addressed for understanding their emergence and diversification ( 40 ). Hence, we identified the association of ARGs with bacterial taxa.…”

Impact of Anthropogenic Activities on the Dissemination of ARGs in the Environment—A Review

“…As the technological processes most often employed in WWTPs do not unfortunately include technologies specifically designed to remove pharmaceuticals from wastewater, these pollutants eventually end up in surface water bodies together with treated wastewater. Effluent wastewater from WWTPs can be, therefore, one of the major sources of ARB and ARGs in water ecosystems [61][62][63][64]. Wastewater treatment plants are among the human-made facilities that create conditions particularly suitable for the occurrence of processes of exchange of genetic structures, including ARGs, between microorganisms dwelling in wastewater being treated in these facilities.…”

“…One of the biggest challenges connected with the operation of waste disposal plants is to handle LL generated in landfills in an environmentally sound manner [120]. A popular solution is the treatment of LL together with municipal wastewater at WWTPs [121], which results in the additional enrichment of municipal waste with antibiotics, ARB and ARGs [61]. Table 6 presents the specification of antibiotics detected in LL.…”