Abundances of Clinically Relevant Antibiotic Resistance Genes and Bacterial Community Diversity in the Weihe River, China

Abstract

The spread of antibiotic resistance genes in river systems is an emerging environmental issue due to their potential threat to aquatic ecosystems and public health. In this study, we used droplet digital polymerase chain reaction (ddPCR) to evaluate pollution with clinically relevant antibiotic resistance genes (ARGs) at 13 monitoring sites along the main stream of the Weihe River in China. Six clinically relevant ARGs and a class I integron-integrase (intI1) gene were analyzed using ddPCR, and the bacterial community was evaluated based on the bacterial 16S rRNA V3–V4 regions using MiSeq sequencing. The results indicated Proteobacteria, Actinobacteria, Cyanobacteria, and Bacteroidetes as the dominant phyla in the water samples from the Weihe River. Higher abundances of blaTEM, strB, aadA, and intI1 genes (103 to 105 copies/mL) were detected in the surface water samples compared with the relatively low abundances of strA, mecA, and vanA genes (0–1.94 copies/mL). Eight bacterial genera were identified as possible hosts of the intI1 gene and three ARGs (strA, strB, and aadA) based on network analysis. The results suggested that the bacterial community structure and horizontal gene transfer were associated with the variations in ARGs.

Co-selective Pressure of Cadmium and Doxycycline on the Antibiotic and Heavy Metal Resistance Genes in Ditch Wetlands

“…Meanwhile, Hydrogenophaga might be a potential host for the MRG subtype czcS after both short-term and long-term exposure (Figure 6). This was consistent with results from a previous study reporting that Hydrogenophaga was significantly predominant in Hengshi sediments, with a higher abundance of As, Cu, and Zn resistance genes (Wang X. et al, 2018). Moreover, most of the ARGs and MRGs co-occurred in Acinetobacter and Pseudomonas (Figure 6).…”

Diversity of Multidrug-Resistant Bacteria in an Urbanized River: A Case Study of the Potential Risks from Combined Sewage Overflows

“…The diversity of MDR isolates was highest at the upstream site and significantly lower at the CSO site during the overflow event (Figure 5). This is consistent with several prior studies that have documented reduced diversity in environments experiencing wastewater pollution [66][67][68]. In our study, nearly all (97%) isolates were Proteobacteria and Bacteroidetes, which are among the phyla most commonly reported in rivers, tap water, and wastewater [69][70][71].…”

Antimicrobial Resistance in Rivers: A Review of the Genes Detected and New Challenges

“…Methods for studying microbial DNA generally use subsamples of each water sample (e.g., from 150-300 ml to 1 L), which are filtered on polycarbonate membrane filters (0.22 μm; X. Wang et al, 2018); in some cases, prefiltration on 30-μm filters is performed to eliminate large particles. The microbial cells are then recovered from the filters (agitation with PBS plus Tween 20 at 28 °C, vortexing, and centrifuging the samples), and the DNA is extracted from the biomass with lysozyme, proteinase K, and phenol:chloroform:isoamylic alcohol (25:24:1).…”

“…A large number of genomic tools are used to determine microbial community composition and the presence of ARGs. For example, culture-independent methods such as PCR, qPCR, high-capacity qPCR arrays, droplet digital PCR (ddPCR), and DNA microarray are frequently used (Larsson et al, 2018;L.-G. Li et al, 2020;X. Wang et al, 2018); and ddPCR and DNA microarray can simultaneously detect a large number of ARGs in a single assay.…”