scholarly journals Genome-Resolved Metagenomics and Antibiotic Resistance Genes Analysis in Reclaimed Water Distribution Systems

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3477
Author(s):  
Changzhi Wang ◽  
Pei-Ying Hong
Keyword(s):  
Antibiotic Resistance ◽  
Relative Abundance ◽  
Resistance Genes ◽  
Distribution Systems ◽  
Water Distribution ◽  
Reclaimed Water ◽  
Water Distribution Systems ◽  
Antibiotic Resistance Genes ◽  
Quality Data ◽  
Metagenomic Data

Water reuse is increasingly pursued to alleviate global water scarcity. However, the wastewater treatment process does not achieve full removal of biological contaminants from wastewater, hence microorganisms and their genetic elements can be disseminated into the reclaimed water distribution systems (RWDS). In this study, reclaimed water samples are investigated via metagenomics to assess their bacterial diversity, metagenome-assembled genomes (MAGs) and antibiotic resistance genes (ARGs) at both point of entry (POE) and point of use (POU) in 3 RWDS. The number of shared bacterial orders identified by metagenome was higher at the POE than POU among the three sites, indicating that specific conditions in RWDS can cause further differentiation in the microbial communities at the end of the distribution system. Two bacterial orders, namely Rhizobiales and Sphingomonadales, had high replication rates in two of the examined RWDS (i.e., site A and B), and were present in higher relative abundance in POU than at POE. In addition, MAG and ARG relative abundance exhibited a strong correlation (R2 = 0.58) in POU, indicating that bacteria present in POU may have a high incidence of ARG. Specifically, resistance genes associated with efflux pump mechanisms (e.g., adeF and qacH) increased in its relative abundance from POU to POE at two of the RWDS (i.e., site A and B). When correlated with the water quality data that suggests a significantly lower dissolved organic carbon (DOC) concentration at site D than the other two RWDS, the metagenomic data suggest that low DOC is needed to maintain the biological stability of reclaimed water along the distribution network.

scholarly journals Degradation Sulfamethoxazole by Chlorination in Water Distribution Systems: Kinetics, Toxicity, and Antibiotic Resistance Genes

2021 ◽  
Author(s):  
Luo Xu ◽  
cong li ◽  
Guozijian Wei ◽  
Jie Ji ◽  
Eric Lichtfouse ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Distribution Systems ◽  
Water Distribution ◽  
Degradation Rate ◽  
Tap Water ◽  
Water Distribution Systems ◽  
Antibiotic Resistance Genes ◽  
Feed Additives ◽  
Batch Reactors

Abstract Sulfamethoxazole (SMX) is a veterinary drugs and feed additives, which has been frequently detected in surface waters in recent years. This paper investigated the kinetics, evolution of toxicity and antibiotic resistance genes (ARGs) of SMX in reactions with free chlorine (FC) to evaluate the fate of SMX in batch reactors and water distribution systems (WDS). In the range of investigated pH (6.3 – 9.0), the SMX degradation had the fastest rate at close to neutral pH. The chlorination of SMX could be described by the first-order kinetics, with specific second-order rate constants in batch reactors of (2.23 ± 0.07) × 102 M− s and (5.04 ± 0.30) × 101 M− s− for HClO and ClO−, respectively. And in WDS of (1.76 ± 0.07) × 102 M− s− and (4.06 ± 0.62) × 101 M− s−, respectively. The SMX degradation rate was also affected by pipe material, and the rate followed the order: stainless-steel pipe (SS) > ductile iron pipe (DI) > polyethylene pipe (PE). The flow rate from 0.7 to 1.5 m/s led to an increase of SMX degradation rate in DI, but the increase was limited. In addition, SMX could increase the toxicity of water initially, yet the toxicity reduced to the level of tap water after 2 hours chlorination. The relative abundance of ARGs (sul1 and sul2) of tap water samples was significantly increased under different conditions including only use SMX, chlorination products of SMX, or pretreatment with SMX followed by chlorination.

Characterization of Integrons and Sulfonamide Resistance Genes among Bacteria from Drinking Water Distribution Systems in Southwestern Nigeria

Chemotherapy ◽  
2016 ◽  
Vol 62 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Ayodele T. Adesoji ◽  
Adeniyi A. Ogunjobi ◽  
Isaac O. Olatoye
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Water Samples ◽  
Distribution Systems ◽  
Water Distribution ◽  
Tap Water ◽  
Bacterial Species ◽  
Water Distribution Systems ◽  
Integrase Gene ◽  
Class 1

Background: The emergence of antibiotic resistance among pathogenic bacteria in clinical and environmental settings is a global problem. Many antibiotic resistance genes are located on mobile genetic elements such as plasmids and integrons, enabling their transfer among a variety of bacterial species. Water distribution systems may be reservoirs for the spread of antibiotic resistance. Materials and Methods: Bacteria isolated from raw, treated, and municipal tap water samples from selected water distribution systems in south-western Nigeria were investigated using the point inoculation method with seeded antibiotics, PCR amplification, and sequencing for the determination of bacterial resistance profiles and class 1/2 integrase genes and gene cassettes, respectively. Results:sul1,sul2, and sul3 were detected in 21.6, 27.8, and 0% of the isolates, respectively (n = 162). Class 1 and class 2 integrons were detected in 21.42 and 3.6% of the isolates, respectively (n = 168). Genes encoding resistance to aminoglycosides (aadA2, aadA1, and aadB), trimethoprim (dfrA15, dfr7, and dfrA1), and sulfonamide (sul1) were detected among bacteria with class 1 integrons, while genes that encodes resistance to strepthothricin (sat2) and trimethoprim (dfrA15) were detected among bacteria with class 2 integrons. Conclusions: Bacteria from these water samples are a potential reservoir of multidrug-resistant traits including sul genes and mobile resistance elements, i.e. the integrase gene.

scholarly journals Metagenomic Community Composition and Resistome Analysis in a Full-scale Cold Climate Wastewater Treatment Plant

2021 ◽  
Author(s):  
Miguel Uyaguari
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Relative Abundance ◽  
Resistance Genes ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Antibiotic Resistance Genes ◽  
Gene Copies ◽  
Final Effluent

Abstract Background: Wastewater treatment plants are an essential part of maintaining the health and safety of the general public. However, they are also an anthropogenic source of antibiotic resistance genes. In this study, we characterized the resistome, the distribution of classes 1-3 integron-integrase genes (intI1, intI2, and intI3) as mobile genetic element biomarkers, and the bacterial and phage community compositions in the North End Sewage Treatment Plant in Winnipeg, Manitoba. Samples were collected from raw sewage, returned activated sludge, final effluent, and dewatered sludge. A total of 28 bacterial and viral metagenomes were sequenced over two seasons, fall and winter. Integron-integrase genes, the 16S rRNA gene, and the coliform beta-glucuronidase gene were also quantified during this time period. Results: Bacterial classes observed above 1% relative abundance in all treatments were Actinobacteria (39.24% ± 0.25%), Beta-proteobacteria (23.99% ± 0.16%), Gamma-proteobacteria (11.06% ± 0.09%), and Alpha-proteobacteria (9.18 ± 0.04%). Families within the Caudovirales order: Siphoviridae (48.69% ± 0.10%), Podoviridae (23.99% ± 0.07%), and Myoviridae (19.94% ± 0.09%) were the dominant phage observed throughout the NESTP. The most abundant bacterial genera (in terms of average percent relative abundance) in influent, returned activated sludge, final effluent, and sludge, respectively, includes Mycobacterium (37.4%, 18.3%, 46.1%, and 7.7%), Acidovorax (8.9%, 10.8%, 5.4%, and 1.3%), and Polaromonas (2.5%, 3.3%, 1.4%, and 0.4%).The most abundant class of antibiotic resistance in bacterial samples was tetracycline resistance (17.86% ± 0.03%) followed by peptide antibiotics (14.24% ± 0.03%), and macrolides (10.63% ± 0.02%). Similarly, the phage samples contained a higher prevalence of macrolide (30.12% ± 0.30%), peptide antibiotic (10.78% ± 0.13%), and tetracycline (8.69% ± 0.11%) resistance. In addition, intI1 was the most abundant integron-integrase gene throughout treatment (1.14x104 gene copies/mL) followed by intI3 (4.97x103 gene copies/mL) while intI2 abundance remained low (6.4x101 gene copies/mL).Conclusions: The wastewater treatment plant successfully reduced the abundance of bacteria, DNA bacteriophages, and antibiotic resistance genes although many of them still remained in effluent and biosolids. The presence of integron-integrase genes throughout treatment and in effluent suggests that antibiotic resistance genes could be actively disseminating resistance between both environmental and pathogenic bacteria.

Sign in / Sign up

Export Citation Format

Share Document