scholarly journals Wastewater-Based Surveillance of Antibiotic Resistance Genes Associated with Tuberculosis Treatment Regimen in KwaZulu Natal, South Africa

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1362
Author(s):  
Hlengiwe N. Mtetwa ◽  
Isaac D. Amoah ◽  
Sheena Kumari ◽  
Faizal Bux ◽  
Poovendhree Reddy
Keyword(s):  
South Africa ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Molecular Techniques ◽  
Treated Wastewater ◽  
Significant Finding ◽  
Drug Resistant ◽  
Tb Treatment ◽  
Essential Components

Essential components of public health include strengthening the surveillance of infectious diseases and developing early detection and prevention policies. This is particularly important for drug-resistant tuberculosis (DR-TB), which can be explored by using wastewater-based surveillance. This study aimed to use molecular techniques to determine the occurrence and concentration of antibiotic-resistance genes (ARGs) associated with tuberculosis (TB) resistance in untreated and treated wastewater. Raw/untreated and treated (post-chlorination) wastewater samples were taken from three wastewater treatment plants (WWTPs) in South Africa. The ARGs were selected to target drugs used for first- and second-line TB treatment. Both conventional polymerase chain reaction (PCR) and the more advanced droplet digital PCR (ddPCR) were evaluated as surveillance strategies to determine the distribution and concentration of the selected ARGs. The most abundant ARG in the untreated wastewater was the rrs gene, associated with resistance to the aminoglycosides, specifically streptomycin, with median concentration ranges of 4.69–5.19 log copies/mL. In contrast, pncA gene, associated with resistance to the TB drug pyrazinamide, was the least detected (1.59 to 2.27 log copies/mL). Resistance genes associated with bedaquiline was detected, which is a significant finding because this is a new drug introduced in South Africa for the treatment of multi-drug resistant TB. This study, therefore, establishes the potential of molecular surveillance of wastewater for monitoring antibiotic resistance to TB treatment in communities.

scholarly journals Antibiotic resistance genes and mobile genetic elements removal from treated wastewater by sewage-sludge biochar and iron-oxide coated sand

2020 ◽  
Author(s):  
David Calderón-Franco ◽  
Apoorva Seeram ◽  
Gertjan Medema ◽  
Mark C. M. van Loosdrecht ◽  
David G. Weissbrodt
Keyword(s):  
Antibiotic Resistance ◽  
Iron Oxide ◽  
Sewage Sludge ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Environmental Dna ◽  
Extracellular Dna ◽  
Treated Wastewater ◽  
Dna Adsorption ◽  
Coated Sand

AbstractDisinfection of treated wastewater in wastewater treatment plants (WWTPs) is used to minimize emission of coliforms, pathogens, and antibiotic resistant bacteria (ARB) in the environment. However, the fate of free-floating extracellular DNA (eDNA) that do carry antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) is overlooked. Water technologies are central to urban and industrial ecology for sanitation and resource recovery. Biochar produced by pyrolysis of sewage sludge and iron-oxide-coated sands recovered as by-product of drinking water treatment were tested as adsorbents to remove ARGs and MGEs from WWTP effluent. DNA adsorption properties and materials applicability were studied in batch and up-flow column systems at bench scale. Breakthrough curves were measured with ultrapure water and treated wastewater at initial DNA concentrations of 0.1-0.5 mg mL-1 and flow rates of 0.1-0.5 mL min-1. Batch tests with treated wastewater indicated that the adsorption profiles of biochar and iron-oxide coated sand followed a Freundlich isotherm, suggesting a multilayer adsorption of nucleic acids. Sewage-sludge biochar exhibited higher DNA adsorption capacity (1 mg g-1) and longer saturation breakthrough times (4 to 10 times) than iron-oxide coated sand (0.2 mg g-1). The removal of a set of representative ARGs and MGEs was measured by qPCR comparing the inlet and outlet of the plug-flow column fed with treated wastewater. ARGs and MGEs present as free-floating eDNA were adsorbed by sewage-sludge biochar at 85% and iron-oxide coated sand at 54%. From the environmental DNA consisting of the free-floating extracellular DNA plus the intracellular DNA of the cells present in the effluent water, 97% (sewage-sludge biochar) and 66% (iron-oxide coated sand) of the tested genes present were removed. Sewage-sludge biochar displayed interesting properties to minimize the spread of antimicrobial resistances to the aquatic environment while strengthening the role of WWTPs as resource recovery factories.Graphical abstractHighlightsSewage-sludge biochar and iron oxide coated sands were tested to adsorb DNA and cells.Biochar removed 97% of genes tested from environmental DNA of unfiltered effluent.85% of ARGs and MGEs of free-floating extracellular DNA were retained by biochar.Biochar is a WWTP by-product that can be re-used for public health sanitation.

Occurrence of enterococci harbouring clinically important antibiotic resistance genes in the aquatic environment in Gauteng, South Africa

2019 ◽  
Vol 245 ◽  
pp. 1041-1049 ◽  
Author(s):  
Thabo Hamiwe ◽  
Marleen M. Kock ◽  
Cliff A. Magwira ◽  
John F. Antiabong ◽  
Marthie M. Ehlers
Keyword(s):  
South Africa ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Aquatic Environment ◽  
Antibiotic Resistance Genes

scholarly journals Localized effect of treated wastewater effluent on the resistome of an urban watershed

GigaScience ◽  
2020 ◽  
Vol 9 (11) ◽  
Author(s):  
Christopher N Thornton ◽  
Windy D Tanner ◽  
James A VanDerslice ◽  
William J Brazelton
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Resistance Genes ◽  
Fecal Contamination ◽  
Antibiotic Resistance Genes ◽  
Wastewater Effluent ◽  
Treated Wastewater ◽  
Urban Watershed ◽  
Wastewater Discharge ◽  
Treated Effluent

Abstract Background Wastewater treatment is an essential tool for maintaining water quality in urban environments. While the treatment of wastewater can remove most bacterial cells, some will inevitably survive treatment to be released into natural environments. Previous studies have investigated antibiotic resistance within wastewater treatment plants, but few studies have explored how a river’s complete set of antibiotic resistance genes (the “resistome") is affected by the release of treated effluent into surface waters. Results Here we used high-throughput, deep metagenomic sequencing to investigate the effect of treated wastewater effluent on the resistome of an urban river and the downstream distribution of effluent-associated antibiotic resistance genes and mobile genetic elements. Treated effluent release was found to be associated with increased abundance and diversity of antibiotic resistance genes and mobile genetic elements. The impact of wastewater discharge on the river’s resistome diminished with increasing distance from effluent discharge points. The resistome at river locations that were not immediately downstream from any wastewater discharge points was dominated by a single integron carrying genes associated with resistance to sulfonamides and quaternary ammonium compounds. Conclusions Our study documents variations in the resistome of an urban watershed from headwaters to a major confluence in an urban center. Greater abundances and diversity of antibiotic resistance genes are associated with human fecal contamination in river surface water, but the fecal contamination effect seems to be localized, with little measurable effect in downstream waters. The diverse composition of antibiotic resistance genes throughout the watershed suggests the influence of multiple environmental and biological factors.

scholarly journals Occurrence and Removal of Antibiotics, Antibiotic-Resistance Genes and Bacterial Communities in Hospital Wastewater

2021 ◽  
Author(s):  
Shijie Yao ◽  
Jianfeng Ye ◽  
Qing Yang ◽  
Yaru Hu ◽  
Tianyang Zhang ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
16S Rrna ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Generation Cephalosporin ◽  
Treated Wastewater ◽  
Hospital Wastewater ◽  
Opportunistic Bacteria ◽  
Relative Abundances

Abstract Hospital wastewater contains a variety of human-related antibiotics and pathogens, which makes the treatment of hospital wastewater essential. However, there is a lack of research on these pollutants in hospital wastewater treatment plants. In this study, the characteristics and removal of antibiotics and antibiotic resistance genes (ARGs) in independent treatment processes of hospitals of different scales (primary hospital H1, secondary hospital H2, and tertiary hospital H3) were investigated. The occurrence of antibiotics and ARGs in wastewater from three hospitals varied greatly. The first-generation cephalosporin cefradine was detected at a concentration of 2.38 μg/L in untreated wastewater of H1, while the fourth-generation cephalosporin cefepime had the highest concentration, 540.39 μg/L, in H3. Ofloxacin was detected at a frequency of 100% and had removal efficiencies of 44.2%, 51.5%, and 81.6% for H1, H2, and H3, respectively. The highest relative abundances of the β-lactam resistance gene blaGES-1 (1.77×10-3 copies/16S rRNA), quinolone resistance gene qnrA (8.81×10-6 copies/16S rRNA), and integron intI1 (1.86×10-4 copies/16S rRNA) were detected in the treated wastewaters. The concentrations of several ARGs were increased in the treated wastewater (e.g., blaOXA-1, blaOXA-10 and blaTEM-1). Several pathogenic or opportunistic bacteria (e.g., Acinetobacter, Klebsiella, Aeromonas, and Pseudomonas) were observed with high relative abundances in the treated wastewater. These results suggested the co-occurrence of novel antibiotics, ARGs, and antibiotic-resistant pathogens in hospital wastewater that may spread into the receiving water environment.

scholarly journals Occurrence of Fluoroquinolones and Sulfonamides Resistance Genes in Wastewater and Sludge at Different Stages of Wastewater Treatment: A Preliminary Case Study

2020 ◽  
Vol 10 (17) ◽  
pp. 5816
Author(s):  
Damian Rolbiecki ◽  
Monika Harnisz ◽  
Ewa Korzeniewska ◽  
Łukasz Jałowiecki ◽  
Grażyna Płaza
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Sewage Sludge ◽  
Resistance Genes ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Treated Wastewater ◽  
Standard Polymerase Chain Reaction ◽  
Wastewater Samples

This study identified differences in the prevalence of antibiotic resistance genes (ARGs) between wastewater treatment plants (WWTPs) processing different proportions of hospital and municipal wastewater as well as various types of industrial wastewater. The influence of treated effluents discharged from WWTPs on the receiving water bodies (rivers) was examined. Genomic DNA was isolated from environmental samples (river water, wastewater and sewage sludge). The presence of genes encoding resistance to sulfonamides (sul1, sul2) and fluoroquinolones (qepA, aac(6′)-Ib-cr) was determined by standard polymerase chain reaction (PCR). The effect of the sampling season (summer – June, fall – November) was analyzed. Treated wastewater and sewage sludge were significant reservoirs of antibiotic resistance and contained all of the examined ARGs. All wastewater samples contained sul1 and aac(6′)-lb-cr genes, while the qepA and sul2 genes occurred less frequently. These observations suggest that the prevalence of ARGs is determined by the type of processed wastewater. The Warmia and Mazury WWTP was characterized by higher levels of the sul2 gene, which could be attributed to the fact that this WWTP processes agricultural sewage containing animal waste. However, hospital wastewater appears to be the main source of the sul1 gene. The results of this study indicate that WWTPs are significant sources of ARGs, contributing to the spread of antibiotic resistance in rivers receiving processed wastewater.

scholarly journals Effect of Urban Wastewater Discharge on the Abundance of Antibiotic Resistance Genes and Antibiotic-Resistant Escherichia coli in Two Italian Rivers

2020 ◽  
Vol 17 (18) ◽  
pp. 6813 ◽  
Author(s):  
Fabrizio Pantanella ◽  
Itziar Lekunberri ◽  
Antonella Gagliardi ◽  
Giuseppe Venuto ◽  
Alexandre Sànchez-Melsió ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Treated Wastewater ◽  
Flow Volume ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Absolute Concentrations ◽  
The Impact

Background: Wastewater treatment plants (WWTPs) are microbial factories aimed to reduce the amount of nutrients and pathogenic microorganisms in the treated wastewater before its discharge into the environment. We studied the impact of urban WWTP effluents on the abundance of antibiotic resistance genes (ARGs) and antibiotic-resistant Escherichia coli (AR-E. coli) in the last stretch of two rivers (Arrone and Tiber) in Central Italy that differ in size and flow volume. Methods: Water samples were collected in three seasons upstream and downstream of the WWTP, at the WWTP outlet, and at sea sites near the river mouth, and analyzed for the abundance of ARGs by qPCR and AR-E. coli using cultivation followed by disk diffusion assays. Results: For all studied genes (16S rRNA, intI1, sul1, ermB, blaTEM, tetW and qnrS), absolute concentrations were significantly higher in the Tiber than in the Arrone at all sampling sites, despite their collection date, but the prevalence of target ARGs within bacterial communities in both rivers was similar. The absolute concentrations of most ARGs were also generally higher in the WWTP effluent with median levels between log 4 and log 6 copies per ml but did not show differences along the studied stretches of rivers. Statistically significant site effect was found for E. coli phenotypic resistance to tetracycline and ciprofloxacin in the Arrone but not in the Tiber. Conclusions: In both rivers, diffuse or point pollution sources other than the studied WWTP effluents may account for the observed resistance pattern, although the Arrone appears as more sensitive to the wastewater impact considering its lower flow volume.

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