scholarly journals Comparative analysis of intracellular and extracellular antibiotic resistance gene abundance in anaerobic membrane bioreactor effluent

2019 ◽  
Author(s):  
Phillip Wang ◽  
Moustapha Harb ◽  
Ali Zarei-Baygi ◽  
Lauren B. Stadler ◽  
Adam L. Smith
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Antibiotic Resistance Gene ◽  
Significant Risk ◽  
Size Exclusion ◽  
Treatment Technology ◽  
Large Plasmids ◽  
Activated Sludge Processes

AbstractThe growing practice of wastewater reuse poses a significant risk to further dissemination of antibiotic resistance due to the abundance of antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) in wastewater effluents. Anaerobic membrane bioreactors (AnMBRs) are an emerging wastewater treatment technology capable of reducing the total ARGs and ARB load discharged to receiving environments compared to conventional aerobic treatment processes. While size exclusion is effective at retaining ARB and its associated intracellular ARGs, the abundance and fate of extracellular ARGs in an AnMBR effluent have not been examined. This study elucidates the effect of combined antibiotics loading (ampicillin, erythromycin, and sulfamethoxazole) on the abundance of intracellular and extracellular ARGs in an AnMBR effluent over a period of five weeks. Quantification of targeted genes revealed an overall enrichment of intracellular ARGs (iARGs) and depletion of extracellular (exARGs) in response to antibiotics addition, which suggests exARG uptake as a significant mode of horizontal gene transfer in AnMBR effluents. Comparison of the iARG and exARG abundance profiles showed a potential bias for exARG uptake located on small plasmids compared to large plasmids.ImportanceAntibiotic resistance dissemination is facilitated through horizontal gene transfer (HGT) of ARGs. Currently, conjugation is considered to be the dominant mechanism during wastewater treatment. However, recent studies have detected high abundances of exARGs, implying that transformation may play a greater role in dissemination. While previous studies quantified iARGs and exARGs in wastewater treatment facilities, they did not evaluate temporal changes between the two forms. Further, almost no research has differentiated between iARGs and exARGs in anaerobic processes, which are being considered to replace aerobic activated sludge processes. This study specifically investigates the abundance of targeted iARGs and exARGs in AnMBRs in response to antibiotic pressure to quantify potential exchange of ARGs between intracellular and extracellular compartments. Our findings suggest that exARGs located on small plasmids are preferentially taken up by cells under antibiotic pressure compared to large plasmids, which implies heterogenous HGT mechanisms among the plasmid community.

scholarly journals Quantitative Occurrence of Antibiotic Resistance Genes among Bacterial Populations from Wastewater Treatment Plants Using Activated Sludge

2019 ◽  
Vol 9 (3) ◽  
pp. 387 ◽  
Author(s):  
Adriana Osińska ◽  
Ewa Korzeniewska ◽  
Monika Harnisz ◽  
Sebastian Niestępski
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Gene ◽  
Antibiotic Resistance Genes ◽  
Treated Wastewater ◽  
Beta Lactams ◽  
Treatment Technology ◽  
Bacterial Populations

Wastewater treatment plants (WWTPs) are an important reservoir in the development of drug resistance phenomenon and they provide a potential route of antibiotic resistance gene (ARGs) dissemination in the environment. The aim of this study was to assess the role of WWTPs in the spread of ARGs. Untreated and treated wastewater samples that were collected from thirteen Polish WWTPs (applying four different modifications of activated sludge–based treatment technology) were analyzed. The quantitative occurrence of genes responsible for the resistance to beta-lactams and tetracyclines was determined using the real-time PCR method. Such genes in the DNA of both the total bacterial population and of the E. coli population were analyzed. Among the tested genes that are responsible for the resistance to beta-lactams and tetracyclines, blaOXA and blaTEM and tetA were dominant, respectively. This study found an insufficient reduction in the quantity of the genes that are responsible for antibiotic resistance in wastewater treatment processes. The results emphasize the need to monitor the presence of genes determining antibiotic resistance in the wastewater that is discharged from treatment plants, as they can help to identify the hazard that treated wastewater poses to public health.

scholarly journals The effect of sequencing and assembly on the inference of horizontal gene transfer on chromosomal and plasmid phylogenies

2021 ◽  
Author(s):  
Jana Sanne Huisman ◽  
Timothy G Vaughan ◽  
Adrian Egli ◽  
Sarah Tschudin-Sutter ◽  
Tanja Stadler ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Resistance Gene ◽  
Antibiotic Resistance Gene ◽  
Sequencing Data ◽  
Short Read ◽  
Assembly Method ◽  
Long Reads ◽  
The Impact

The spread of antibiotic resistance genes on plasmids is a threat to human and animal health. Phylogenies of bacteria and their plasmids contain clues regarding the frequency of plasmid transfer events, as well as the co-evolution of plasmids and their hosts. However, whole genome sequencing data from diverse ecological or clinical bacterial samples is rarely used to study plasmid phylogenies and resistance gene transfer. This is partially due to the difficulty to extract plasmids from short-read sequencing data. Here, we use both short- and long-read sequencing data of 24 clinical extended-spectrum beta-lactamase producing Escherichia coli to estimate chromosomal and plasmid phylogenies. We compare the impact of different sequencing and assembly methodologies on these phylogenies and on the inference of horizontal gene transfer. We find chromosomal phylogenies can be estimated robustly with all methods, whereas plasmid phylogenies have more variable topology and branch lengths across the methods used. Specifically, hybrid methods that use long reads to resolve short-read assemblies (HybridSPAdes and Unicycler) perform better than those that started from long-reads during assembly graph generation (Canu). In contrast, the inference of plasmid and antibiotic resistance gene transfer using a parsimony-based criterion is mostly robust to the choice of sequencing and assembly method.

scholarly journals IncHI1A plasmids potentially facilitate a horizontal flow of antibiotic resistance genes to pathogens in microbial communities of urban residential sewage

2021 ◽  
Author(s):  
Asmus Olesen ◽  
Rafel Pinilla-Redondo ◽  
Mads Hansen ◽  
Jakob Russel ◽  
Arnaud Dechesne ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Microbial Communities ◽  
Host Range ◽  
Resistance Genes ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Potential Host

Horizontal gene transfer via plasmids is important for the dissemination of antibiotic resistance genes among medically relevant pathogens. Specifically, the transfer of IncHI1A plasmids is believed to facilitate the spread of antibiotic resistance genes, such as carbapenemases, within the clinically important family Enterobacteriaceae. The microbial community of urban wastewater treatment plants has been shown to be highly permissive towards conjugal transfer of IncP1 plasmids. Here, we tracked the transfer of the P1 plasmid pB10 and the clinically relevant HI1A plasmid R27 in the microbial communities present in urban residential sewage entering full-scale wastewater treatment plants. We found that both plasmids readily transferred to these communities and that strains in the sewage were able to further disseminate them. Furthermore, that R27 has a broad potential host range, but a low host divergence. Interestingly, although the majority of R27 transfer events were to members of Enterobacteriaceae, we found a subset of transfer to other families, even other phyla. Indicating, that HI1A plasmids facilitate horizontal gene transfer both within Enterobacteriaceae, but also across families of especially Gammaproteobacteria, such as Moraxellaceae, Pseudomonadaceae and Shewanellaceae. pB10 displayed a similar potential host range as R27. In contrast to R27, pB10 had a high host divergence. By cultivative enrichment of the transconjugant communities, we show that sewage strains of Enterobacteriaceae and Aeromonadaceae can stably maintain R27 and pB10, respectively. Our results suggest that dissemination in the urban residual water system of HI1A plasmids may result in an accelerated acquisition of antibiotic resistance genes among pathogens.

scholarly journals IncHI1A plasmids potentially facilitate a horizontal flow of antibiotic resistance genes to pathogens in microbial communities of urban residential sewage

2021 ◽  
Author(s):  
Asmus Olesen ◽  
Rafel Pinilla-Redondo ◽  
Mads Hansen ◽  
Jakob Russel ◽  
Arnaud Dechesne ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Microbial Communities ◽  
Host Range ◽  
Resistance Genes ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Potential Host

Horizontal gene transfer via plasmids is important for the dissemination of antibiotic resistance genes among medically relevant pathogens. Specifically, the transfer of IncHI1A plasmids is believed to facilitate the spread of antibiotic resistance genes, such as carbapenemases, within the clinically important family Enterobacteriaceae. The microbial community of urban wastewater treatment plants has been shown to be highly permissive towards conjugal transfer of IncP1 plasmids. Here, we tracked the transfer of the P1 plasmid pB10 and the clinically relevant HI1A plasmid R27 in the microbial communities present in urban residential sewage entering full-scale wastewater treatment plants. We found that both plasmids readily transferred to these communities and that strains in the sewage were able to further disseminate them. Furthermore, that R27 has a broad potential host range, but a low host divergence. Interestingly, although the majority of R27 transfer events were to members of Enterobacteriaceae, we found a subset of transfer to other families, even other phyla. Indicating, that HI1A plasmids facilitate horizontal gene transfer both within Enterobacteriaceae, but also across families of especially Gammaproteobacteria, such as Moraxellaceae, Pseudomonadaceae and Shewanellaceae. pB10 displayed a similar potential host range as R27. In contrast to R27, pB10 had a high host divergence. By culture enrichment of the transconjugant communities, we show that sewage strains of Enterobacteriaceae and Aeromonadaceae can stably maintain R27 and pB10, respectively. Our results suggest that dissemination in the urban residual water system of HI1A plasmids may result in an accelerated acquisition of antibiotic resistance genes among pathogens.

Sign in / Sign up

Export Citation Format

Share Document