Winter is coming - Impact of temperature on the variation of beta-lactamase and mcr genes in a wastewater treatment plant. - Related Documents




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331601.0000Winter is coming - Impact of temperature on the variation of beta-lactamase and mcr genes in a wastewater treatment plant. Wastewater treatment plants (WWTP) play a key role in the dissemination of antibiotic resistance and analyzing the abundance of antibiotic resistance genes (ARGs) and resistant bacteria is necessary to evaluate the risk of proliferation caused by WWTPs. Since few studies investigated the seasonal variation of antibiotic resistance, this study aimed to determine the abundance of beta-lactamase and mcr genes and to characterize phenotypic resistant strains in a WWTP in Germany over the seasons. Wastewater, sewage sludge and effluent samples were collected over a one year period and analyzed using quantitative real-time PCR. Resistant strains were isolated, followed by identification and antibiotic susceptibility testing using VITEK 2. The results show a significantly higher occurrence of nearly all investigated ARGs in the wastewater compared to sewage sludge and effluent. ARG abundance and temperature showed a negative correlation in wastewater and significant differences between ARG abundance during warmer and colder seasons were determined, indicating a seasonal effect. Co-occurrence of mcr-1 and carbapenemase genes in a multi-drug resistant Enterobacter cloacae and Escherichia coli producing extended-spectrum beta-lactamase (ESBL) was determined. To the best of our knowledge, this is the first detection of mcr-1, bla(VIM) and bla(OXA-48) in an ESBL-producing E. coli. Although wastewater treatment reduced the abundance of ARGs and resistant strains, a dissemination into the river might be possible because carbapenemase-, CTX-M- and mcr-1-gene harboring strains were still present in the effluent.202031945531
331510.9999Occurrence of the mcr-1 Colistin Resistance Gene and other Clinically Relevant Antibiotic Resistance Genes in Microbial Populations at Different Municipal Wastewater Treatment Plants in Germany. Seven wastewater treatment plants (WWTPs) with different population equivalents and catchment areas were screened for the prevalence of the colistin resistance gene mcr-1 mediating resistance against last resort antibiotic polymyxin E. The abundance of the plasmid-associated mcr-1 gene in total microbial populations during water treatment processes was quantitatively analyzed by qPCR analyses. The presence of the colistin resistance gene was documented for all of the influent wastewater samples of the seven WWTPs. In some cases the mcr-1 resistance gene was also detected in effluent samples of the WWTPs after conventional treatment reaching the aquatic environment. In addition to the occurrence of mcr-1 gene, CTX-M-32, blaTEM, CTX-M, tetM, CMY-2, and ermB genes coding for clinically relevant antibiotic resistances were quantified in higher abundances in all WWTPs effluents. In parallel, the abundances of Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli were quantified via qPCR using specific taxonomic gene markers which were detected in all influent and effluent wastewaters in significant densities. Hence, opportunistic pathogens and clinically relevant antibiotic resistance genes in wastewaters of the analyzed WWTPs bear a risk of dissemination to the aquatic environment. Since many of the antibiotic resistance gene are associated with mobile genetic elements horizontal gene transfer during wastewater treatment can't be excluded.201728744270
331420.9999Carbapenemase and extended-spectrum β-lactamase producing bacteria isolated from municipal wastewater treatment plant and urban river in Nepal. Municipal wastewater treatment plants (WWTPs) and rivers receiving sewage are known hotspots for antibiotic-resistant bacteria (ARB), harboring a wide variety of antibiotic resistance genes (ARGs) and mobile genetic elements. However, the specific distribution of ARB carrying multiple resistance genes in municipal WWTPs and their receiving rivers in Kathmandu remains unclear. Therefore, this study investigated the proportion of antibiotic-resistant bacterial populations and the presence of various ARGs and integrons in carbapenemase- and extended-spectrum β-lactamase (ESBL)-producing bacteria isolated from municipal wastewater and river water. The improvement in water's physicochemical characteristics and a significant reduction in ARB and antibiotic resistance determinants were observed in treated municipal wastewater compared to untreated wastewater. Among 232 bacterial isolates from these samples, 34.82 % were identified as carbapenemase producers, while 42.50 % were confirmed as ESBL producers. E. coli and K. pneumoniae were the predominant carbapenemase- and ESBL-producing bacteria, with their highest abundance in untreated municipal wastewater. Among carbapenemase-producing bacteria, bla (NDM) and bla (OXA) genes were more prevalent, whereas bla (TEM) and bla (CTX-M) genes were commonly detected in ESBL-producing bacteria. Nearly half of these bacterial isolates carried the intI1 gene, indicating its role in the dissemination of ARGs. These findings underscore the critical role of WWTPs in the removal of chemical and biological pollutants, highlighting their significance in urban ecosystem-based adaptation. However, the simultaneous presence of multiple resistance genes and integrons in ARB contributes to the rising antimicrobial resistance in the environment, emphasizing the need for targeted efforts to manage and mitigate the spread of resistance factors.202540979679
331830.9999Antibiotic resistance genes in bacteriophages from wastewater treatment plant and hospital wastewaters. Antibiotic resistant bacteria (ARB) are a major health risk caused particularly by anthropogenic activities. Acquisition of antibiotic resistances by bacteria is known to have happened before the discovery of antibiotics and can occur through different routes. Bacteriophages are thought to have an important contribution to the dissemination of antibiotic resistance genes (ARGs) in the environment. In this study, seven ARGs (bla(TEM), bla(SHV), bla(CTX-M), bla(CMY), mecA, vanA, and mcr-1) were investigated, in the bacteriophage fraction, in raw urban and hospital wastewaters. The genes were quantified in 58 raw wastewater samples collected at five WWTPs (n = 38) and hospitals (n = 20). All genes were detected in the phage DNA fraction, with the bla genes found in higher frequency. On the other hand, mecA and mcr-1 were the least frequently detected genes. Concentrations varied between 10(2) copies/L and 10(6) copies/L. The gene coding for the resistance to colistin (mcr-1), a last-resort antibiotic for the treatment of multidrug-resistant Gram-negative infections, was identified in raw urban and hospital wastewaters with positivity rates of 19 % and 10 %, respectively. ARGs patterns varied between hospital and raw urban wastewaters, and within hospitals and WWTP. This study suggests that phages are reservoirs of ARGs, and that ARGs (with particularly emphasis on resistance to colistin and vancomycin) in the phage fraction are already widely widespread in the environment with potential large implications for public health.202337315610
329940.9999Metagenomic analysis of β-lactamase and carbapenemase genes in the wastewater resistome. The emergence and spread of resistance to antibiotics among bacteria is the most serious global threat to public health in recent and coming decades. In this study, we characterized qualitatively and quantitatively β-lactamase and carbapenemase genes in the wastewater resistome of Central Wastewater Treatment Plant in Koziegłowy, Poland. The research concerns determination of the frequency of genes conferring resistance to β-lactam and carbapenem antibiotics in the genomes of culturable bacteria, as well as in the wastewater metagenome at three stages of treatment: raw sewage, aeration tank, and final effluent. In the final effluent we found bacteria with genes that pose the greatest threat to public health, including genes of extended spectrum β-lactamases - bla(CTX-M), carbapenemases - bla(NDM), bla(VIM), bla(GES), bla(OXA-48), and showed that during the wastewater treatment their frequency increased. Moreover, the wastewater treatment process leads to significant increase in the relative abundance of bla(TEM) and bla(GES) genes and tend to increase the relative abundance of bla(CTX-M), bla(SHV) and bla(OXA-48) genes in the effluent metagenome. The biodiversity of bacterial populations increased during the wastewater treatment and there was a correlation between the change in the composition of bacterial populations and the variation of relative abundance of β-lactamase and carbapenemase genes. PCR-based quantitative metagenomic analysis combined with analyses based on culture methods provided significant information on the routes of ARBs and ARGs spread through WWTP. The limited effectiveness of wastewater treatment processes in the elimination of antibiotic-resistant bacteria and resistance genes impose the need to develop an effective strategy and implement additional methods of wastewater disinfection, in order to limit the increase and the spread of antibiotic resistance in the environment.202031756613
533050.9999Surveillance on ESBL-Escherichia coli and Indicator ARG in Wastewater and Reclaimed Water of Four Regions of Spain: Impact of Different Disinfection Treatments. In the present study, the occurrence of indicator antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) both in the influent and the effluent of four Spanish wastewater treatment plants (WWTPs) was monitored for 12 months, and the susceptibility profiles of 89 recovered extended spectrum β-lactamase (ESBL)-producing Escherichia coli isolates were obtained against a wide range of antimicrobials. The aim of the study was to better understand whether the current wastewater treatment practices allow us to obtain safe reclaimed water mitigating the spread of ARB and ARGs to the environment. Results showed high concentrations of ESBL-producing E. coli as well as a high prevalence of a range of ARGs in the influent samples. The reclamation treatments implemented in the WWTPs were effective in reducing both the occurrence of ESBL E. coli and ARGs, although significant differences were observed among WWTPs. Despite these reductions in occurrence observed upon wastewater treatment, our findings suggest that WWTP effluents may represent an important source of ARGs, which could be transferred among environmental bacteria and disseminate antimicrobial resistance through the food chain. Remarkably, no major differences were observed in the susceptibility profiles of the ESBL E. coli isolated from influent and effluent waters, indicating that water treatments do not give rise to the emergence of new resistance phenotypes.202336830310
331960.9999Extended-spectrum beta-lactamase (ESBL)-positive Enterobacteriaceae in municipal sewage and their emission to the environment. The spread of Gram-negative bacteria with plasmid-borne extended-spectrum beta-lactamases (ESBLs) has become a worldwide problem. Their prevalence is increasing, both in hospitals and in the environment. The aim of this study was to investigate the presence of ESBL-positive Enterobacteriaceae in municipal sewage and their emission to the ambient air and the river receiving effluent from wastewater treatment plant (WWTP). In the group of 455 isolated strains, up to 19.8% (90 isolates) were phenotypic ESBL-producers. They were detected in the 63 (100%) of sewage samples analyzed, 7 (33.3%) of river water and in 10 (23.8%) of air samples collected at the WWTP area. The plasmid-mediated genes encoding beta-lactams resistance were detected in almost 10% out of bacteria of the WWTP's final effluents and in above 32% out of bacteria of air at the WWTP area. It confirms that those genes are released into the environment, which might facilitate further dissemination among environmental bacteria. Moreover, genes encoding antibiotic resistance were shown to be transferrable to an Escherichia coli recipient strain, which indicates a high possibility of horizontal gene transfer among strains of different genera within the sewage and environmental samples. This study demonstrated that despite the treatment, the municipal sewage may be a reservoir of antibiotic-resistant microorganisms and plasmid-mediated antibiotic resistance genes. This may pose a public health risk, which requires future evaluation and control.201323886578
331370.9999The Prevalence and Characterization of Extended-Spectrum β-Lactamase- and Carbapenemase-Producing Bacteria from Hospital Sewage, Treated Effluents and Receiving Rivers. Hospital sewage plays a key role in the dissemination of antibiotic-resistant genes (ARGs) by serving as an environmental antimicrobial resistance reservoir. In this study, we aimed to characterize the cephalosporin- and carbapenem-resistant isolates from hospital sewage and receiving rivers. The results showed that ESBL (bla(CTX-M)) and carbapenemase genes (bla(NDM) and bla(KPC)) were widely detected in a number of different bacterial species. These resistance genes were mainly harbored in Enterobacteriaceae, followed by Acinetobacter and Aeromonas isolates. More attention should be given to these bacteria as important vectors of ARGs in the environment. Furthermore, we showed that the multidrug resistance phenotype was highly prevalent, which was found in 85.5% Enterobacteriaceae and 75% Acinetobacter strains. Notably, the presence of carbapenemase genes in isolates from treated effluents and receiving rivers indicates that the discharges of wastewater treatment plants could be an important source for high-risk resistance genes propagation to the environment. In conclusion, this study shows a high prevalence of ESBL- and carbapenemase-producing bacteria in hospital sewage and receiving rivers in China. These findings have serious implications for human health, and also suggest the need for more efforts to control the dissemination of resistant bacteria from hospital sewage into the environment.202032069792
331780.9999Prevalence and Diversity of Antibiotic Resistance Genes in Swedish Aquatic Environments Impacted by Household and Hospital Wastewater. Antibiotic-resistant Enterobacteriaceae and non-lactose fermenting Gram-negative bacteria are a major cause of nosocomial infections. Antibiotic misuse has fueled the worldwide spread of resistant bacteria and the genes responsible for antibiotic resistance (ARGs). There is evidence that ARGs are ubiquitous in non-clinical environments, especially those affected by anthropogenic activity. However, the emergence and primary sources of ARGs in the environment of countries with strict regulations for antibiotics usage are not fully explored. The aim of the present study was to evaluate the repertoire of ARGs of culturable Gram-negative bacteria from directionally connected sites from the hospital to the wastewater treatment plant (WWTP), and downstream aquatic environments in central Sweden. The ARGs were detected from genomic DNA isolated from a population of selectively cultured coliform and Gram-negative bacteria using qPCR. The results show that hospital wastewater was a reservoir of several class B β-lactamase genes such as bla (IMP-1) , bla (IMP-2), and bla (OXA-23), however, most of these genes were not observed in downstream locations. Moreover, β-lactamase genes such as bla (OXA-48), bla (CTX-M-8), and bla (SFC-1), bla (V IM-1), and bla (V IM-13) were detected in downstream river water but not in the WWTP. The results indicate that the WWTP and hospital wastewaters were reservoirs of most ARGs and contribute to the diversity of ARGs in associated natural environments. However, this study suggests that other factors may also have minor contributions to the prevalence and diversity of ARGs in natural environments.201931019498
533990.9999Metal impacts on the persistence and proliferation of β-lactam resistance genes in Xiangjiang River, China. Currently, the emergence of clinically relevant multi-resistant bacteria and the associated β-lactamases resistance genes which threaten the last frontier for antibiotics presents a major challenge for medical treatment. Xiangjiang River is typically contaminated with heavy metals due to the intensive metal mining activities within this watershed. The occurrence and distribution of several β-lactam antibiotics and ten β-lactam resistance genes (bla(TEM), bla(VIM), bla(SHV), bla(GES), bla(DHA), bla(OXA-1), bla(OXA-2), bla(OXA-10), bla(CMY-2), and bla(ampC)) were investigated in the Xiangjiang River, China. The absolute abundance of bla genes was as high as (7.0 ± 0.6) × 10(6) copies/mL for surface water and (2.3 ± 0.7) × 10(8) copies/g for sediment. In contrast, all the detected β-lactam antibiotic compounds were below the detection limit. The distribution of individual bla gene subtypes was correlated with speciation of heavy metals which might affect the bacterial community structure. The principal coordinate analysis (PCoA) and Mantal test reconfirmed that the heavy metals had a correlation with the bla genes and the bla genes were correlated with bacterial community structure, suggesting that heavy metals impacted on the distribution of the bla genes by shifting bacterial community structure under the long-term selective pressure. The microcosm experiments indicated metal-induced persistence of bla genes in the resistant bacteria (Bacillus megaterium, Staphylococcus epidermidis). The persistence of β-lactam resistance under metal selective pressure is beneficial to the survival of resistant bacteria, thereby contributing to the shift of the bacterial community structure, consequently impacts on the distribution of bla genes.201931256402
3300100.9999Sewage treatment effluents in Delhi: A key contributor of β-lactam resistant bacteria and genes to the environment. Rapid emergence of antibiotic resistance (AR) in developing countries is posing a greater health risk and increasing the global disease burden. Lack of access to safe drinking water, poor sanitation and inadequate sewage treatment facilities in these countries are fueling the problem associated with emergence of AR. Rapid proliferation of AR mediated by treated and untreated discharges from sewage treatment plants (STPs) is a prime public health concern. This study aims to understand the occurrence, fate, and routes of proliferation of carbapenem (KPC) and extended spectrum β-lactam (ESBL) resistant bacteria, and selected resistant genes in the samples collected from different unit operations in 12 STPs in New Delhi over two seasons. Strong correlation observed between faecal coliform levels and KPC (R = 0.95, p = 0.005, n = 60) and ESBL (R = 0.94, p = 0.004, n = 60) resistant bacteria levels indicates possible association of resistant bacteria with faecal matter. Different unit operations in STPs proved inefficient in treating resistant bacteria and genes present in the wastewater. However, inclusion of tertiary treatment (chlorination) unit and anaerobic digester in the present STPs resulted in better removal of AR. Significant correlations between antibiotic resistant genes (ARGs) and integron levels indicates a potential for higher rate of AR proliferation in the environment. Microbial culturing indicated the presence of clinically significant drug-resistant pathogens such as Escherichia coli, Pseudomonas putida, Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella pneumoniae, Klebsiella oxytoca, Acinetobacter baumannii, Shigella dysentery and Aeromonas caviae in the STP effluents. The emergence and spread of resistant bacteria through STP effluents poses exposure risk for the residents of the city.201728886559
5340110.9998Hospital wastewaters: A reservoir and source of clinically relevant bacteria and antibiotic resistant genes dissemination in urban river under tropical conditions. The occurrence and dissemination of antibiotic resistant genes (ARGs) that are associated with clinical pathogens and the evaluation of associated risks are still under-investigated in developing countries under tropical conditions. In this context, cultivable and molecular approaches were performed to assess the dissemination of bacteria and the antibiotic resistance genes in aquatic environment in Kinshasa, Democratic Republic of the Congo. Cultivable approach quantified β-lactam, carbapenem resistant, and total Escherichia coli and Enterobacteriaceae in river sediments and surface waters that receive raw hospital effluents. The molecular approach utilized Quantitative Polymerase Chain Reaction (qPCR) to quantify the total bacteria and the richness of relevant bacteria (Escherichia coli, Enterococcus, and Pseudomonas), and antibiotic resistance genes (ARGs: bla(OXA-48), bla(CTX-M), bla(IMP), bla(TEM)) in sediment samples. Statistical analysis were employed to highlight the significance of hospital contribution and seasonal variation of bacteria and ARGs into aquatic ecosystems in suburban municipalities of Kinshasa, Democratic Republic of the Congo. The contribution of hospitals to antibiotic resistance proliferation is higher in the dry season than during the wet season (p < 0.05). Hospital similarly contributed Escherichia coli, Enterococcus, and Pseudomonas and ARGs significantly to the sediments in both seasons (p < 0.05). The organic matter content correlated positively with E. coli (r = 0.50, p < 0.05). The total bacterial load correlated with Enterococcus, and Pseudomonas (0.49 < r < 0.69, p < 0.05). Each ARG correlated with the total bacterial load or at least one relevant bacteria (0.41 < r < 0.81, p < 0.05). Our findings confirm that hospital wastewaters contributed significantly to antibiotic resistance profile and the significance of this contribution increased in the dry season. Moreover, our analysis highlights this risk from untreated hospital wastewaters in developing countries, which presents a great threat to public health.202032470679
3312120.9998Monitoring of antimicrobial resistance in hospital, municipal, and treated wastewater in Mbarara, Uganda. OBJECTIVE: The aim of this study was to estimate the prevalence of antimicrobial resistance in the population of Mbarara through analysis of wastewater and determine the effectiveness of wastewater treatment in reducing discharge of antibiotic-resistant bacteria and antibiotic resistance genes into the environment. METHODS: Hospital, municipal, and treated wastewater (collected on 10 different dates) from Mbarara, Uganda, were analysed for extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli using a culture-based method and selected clinically relevant antibiotic resistance genes using quantitative PCR. RESULTS: The finding of this study demonstrated that 30.6% of the total E. coli were ESBL producers, constituting a high proportion compared to studies in other countries. Furthermore, the investigation revealed the widespread distribution of the carbapenemase gene bla(CMY-2) within the population. The comparative study of the inflow and outflow of the waste stabilisation pond system, which is used for wastewater treatment, demonstrated a log reduction of 1.9-2.4 for coliform bacteria and total as well as ESBL-producing E. coli. Conversely, the wastewater treatment was associated with an increase of the antibiotic resistance genes sul1 and tetC. CONCLUSIONS: The study shows that the waste stabilisation pond system is releasing significant amounts of coliform bacteria, E. coli, ESBL-producing E. coli, somatic bacteriophages, and antibiotic resistance genes into the Rwizi River. We also demonstrated that wastewater-based surveillance is a cost-effective method of obtaining information on the prevalence of AMR in the population, especially in countries where clinical surveillance is limited due to a lack of resources and infrastructure.202540962206
5314130.9998High prevalence of colistin resistance genes in German municipal wastewater. Bacterial resistance against the last-resort antibiotic colistin is of increasing concern on a global scale. Wastewater is suspected to be one of the pathways by which resistant bacteria and the respective genes are disseminated. We employed a metagenomics approach to detect and quantify colistin resistance genes in raw municipal wastewater sampled at 9 locations all over Germany (14 samples in total, collected in 2016/2017). Our data support the findings of earlier studies according to which the prevalence of the colistin resistance gene mcr-1 is still low. However, we were able to demonstrate that the total prevalence of colistin resistance genes is dramatically underestimated if the focus is put on that specific gene alone. In comparison to mcr-1, other gene variants like mcr-3 and mcr-7 proved to be 10 to 100 times more abundant in samples of untreated wastewater. The average relative abundances expressed as copies per 16S rRNA gene copies were 2.3×10(-3) for mcr-3, 2.2×10(-4) for mcr-4, 3.0×10(-4) for mcr-5, and 4.4×10(-4) for mcr-7. While these four gene variants were ubiquitous in all 14 samples, mcr-1 was detected only once at a relative abundance of 1.4×10(-5). Our results suggest a high risk of increasing incidence of colistin resistance as large amounts of mcr genes are continuously disseminated to diverse microbial communities via the wastewater path.201931398645
5328140.9998Treatment enhances the prevalence of antibiotic-resistant bacteria and antibiotic resistance genes in the wastewater of Sri Lanka, and India. Wastewater treatment plants (WWTPs) are being debated for being the hot spots for the development of antibiotic resistance in pathogenic microbial communities. We observed the prevalence of antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARG), and multidrug resistance (MDR) in two municipal WWTPs and one hospital WWTP in Western and Southern Sri Lanka, and compared the results with particular reference to Indian and the World scenario to trace the imprints of treatment on ARB and ARG. Result suggests that although wastewater treatment resulted in higher than 1.06 log Escherichia coli (E. coli) reduction at all WWTPs, yet the percent of E. coli resistant to most of the antibiotics increased from influent to effluent. Higher prevalence of ARB, ARG, and MDR were noted in hospital WWTP owing to the higher antibiotic concentrations used and excreted by the patients. With reference to India, the WWTPs in Sri Lanka showed more ARB and a consistent increase in its percentages after the treatment but were less resistant to Fluoroquinolone (FQ). E. coli strains isolated from each location of both countries showed multidrug resistance, which has increased after the treatment and was strongly correlated with FQ in every WWTP. Resistant genes for Fluoroquinolone (FQ) (aac-(6')-1b-cr, qnrB, qnrS), β-lactams (ampC), and sulphonamides (sul1) were common in all the wastewaters except additional parC gene in the hospital effluent of Sri Lanka, implying much higher resistance for quinolones, especially for Ciprofloxacin. Multivariate statistical treatments suggest that effluent showed higher loadings and association for MDR/ARB, where pH change and more extensive interaction with metals during the treatment processes seem to have profound effects.202032006770
5372150.9998Transfer potentials of antibiotic resistance genes in Escherichia spp. strains from different sources. Multidrug-resistant Escherichia coli and antibiotic-resistance genes (ARGs) present a danger to public health. However, information on the dissemination potentials of antibiotic resistance among bacteria from different environments is lacking. We isolated multiple antibiotic-resistant Escherichia spp. from animal farms, hospitals, and municipal wastewater-treatment plants (MWWTPs) using culture-based methods, and carried out resistance phenotype and gene analyses. Thirty-five isolates of multiple antibiotic-resistant Escherichia spp. were further screened to detect 61 ARGs, 18 mobile genetic elements (MGEs), and gene cassettes. The isolates from livestock manure and MWWTPs showed greater diversity in plasmid profiling than hospital wastewater. Each Escherichia sp. carried 21-26 ARGs and 8-12 MGEs. In addition, 11 gene cassettes were detected in 34 Escherichia isolates, with greater diversity in livestock manure and MWWTPs than in hospital wastewater. The results indicated that the potential for ARG transfer was higher in livestock manure and MWWTPs compared with human clinical sources, possibly related to the high occurrence of both residual antibiotics and heavy metals in these environments.202031896018
5341160.9998Occurrence of Bacterial Markers and Antibiotic Resistance Genes in Sub-Saharan Rivers Receiving Animal Farm Wastewaters. Antibiotic resistant bacteria and genes which confer resistance to antibiotics from human/animal sources are currently considered a serious environmental and a public health concern. This problem is still little investigated in aquatic environment of developing countries according to the different climatic conditions. In this research, the total bacterial load, the abundance of relevant bacteria (Escherichia coli (E. coli), Enterococcus (Ent), and Pseudomonas), and antibiotic resistance genes (ARGs: bla(OXA-48), bla(CTX-M), sul1, sul2, sul3, and tet(B)) were quantified using Quantitative Polymerase Chain Reaction (qPCR) in sediments from two rivers receiving animal farming wastewaters under tropical conditions in Kinshasa, capital city of the Democratic Republic of the Congo. Human and pig host-specific markers were exploited to examine the sources of contamination. The total bacterial load correlated with relevant bacteria and genes bla(OXA-48), sul3, and tet(B) (P value < 0.01). E. coli strongly correlated with 16s rDNA, Enterococcus, Pseudomonas spp., bla(OXA-48), sul3, and tet(B) (P value < 0.01) and with bla(CTX-M), sul1, and sul2 at a lower magnitude (P value < 0.05). The most abundant and most commonly detected ARGs were sul1, and sul2. Our findings confirmed at least two sources of contamination originating from pigs and anthropogenic activities and that animal farm wastewaters didn't exclusively contribute to antibiotic resistance profile. Moreover, our analysis sheds the light on developing countries where less than adequate infrastructure or lack of it adds to the complexity of antibiotic resistance proliferation with potential risks to the human exposure and aquatic living organisms. This research presents useful tools for the evaluation of emerging microbial contaminants in aquatic ecosystems which can be applied in the similar environment.201931619758
3298170.9998Comparison of antibiotic-resistant bacteria and antibiotic resistance genes abundance in hospital and community wastewater: A systematic review. Antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) are constantly shed into the aquatic environment, with hospital wastewater potentially acting as an important source for resistance spread into the environment. A systematic review was conducted aiming to investigate the role of hospital wastewater on dissemination of antimicrobial resistance in the aquatic environment. Studies included in the review compared the prevalence of ARB and/or ARGs in hospital versus community wastewater. Data were extracted on ARB and/or ARG prevalence. Data on sampling techniques, microbiological methodology and risk of bias of included studies were recorded. Thirty-seven studies were included. Higher frequencies of antibiotic resistance determinants were found in hospital wastewater compared to community sources in 30/37 (81%) of included studies. However, trends for specific multi-drug-resistant bacteria differed. Antibiotic-resistant Gram-negative were more prevalent in hospital compared to community wastewaters, with higher concentrations of extended-spectrum-beta-lactamase-producing pathogens and carbapenemase-producing Enterobacteriaceae in hospital sources in 9/9 studies and 6/7 studies, respectively. Hospitals did not contribute consistently to the abundance of vancomycin-resistant Enterococci (VRE); 5/10 studies found higher abundance of VRE in hospital compared to community wastewaters. Reporting on sampling methods, wastewater treatment processes and statistical analysis were at high risk of bias. Extreme heterogeneity in study methods and outcome reporting precluded meta-analysis. Current evidence concurs that hospital wastewater is an important source for antibiotic resistance in aquatic environments, mainly multidrug-resistant Gram-negative bacteria. Future research is needed to assess the effect of wastewater treatment processes on overall antibiotic resistance in the aquatic environment.202032758846
5312180.9998Presence and Persistence of ESKAPEE Bacteria before and after Hospital Wastewater Treatment. The metagenomic surveillance of antimicrobial resistance in wastewater has been suggested as a methodological tool to characterize the distribution, status, and trends of antibiotic-resistant bacteria. In this study, a cross-sectional collection of samples of hospital-associated raw and treated wastewater were obtained from February to March 2020. Shotgun metagenomic sequencing and bioinformatic analysis were performed to characterize bacterial abundance and antimicrobial resistance gene analysis. The main bacterial phyla found in all the samples were as follows: Proteobacteria, Bacteroides, Firmicutes, and Actinobacteria. At the species level, ESKAPEE bacteria such as E. coli relative abundance decreased between raw and treated wastewater, but S. aureus, A. baumannii, and P. aeruginosa increased, as did the persistence of K. pneumoniae in both raw and treated wastewater. A total of 172 different ARGs were detected; bla(OXA), bla(VEB), bla(KPC), bla(GES), mphE, mef, erm, msrE, AAC(6'), ant(3″), aadS, lnu, PBP-2, dfrA, vanA-G, tet, and sul were found at the highest abundance and persistence. This study demonstrates the ability of ESKAPEE bacteria to survive tertiary treatment processes of hospital wastewater, as well as the persistence of clinically important antimicrobial resistance genes that are spreading in the environment.202438930614
5349190.9998Spread and persistence of antimicrobial resistance genes in wastewater from human and animal sources in São Paulo, Brazil. The spread of antimicrobial resistance (AMR) through multiple reservoirs is a global concern. Wastewater is a critical AMR dissemination source, so this study aimed to assess the persistence of resistance genetic markers in wastewater using a culture-independent approach. Raw and treated wastewater samples (n = 121) from a wastewater treatment plant (WWTP), a human hospital, a veterinary hospital, and a pig farm were monthly collected and concentrated by filtration. DNA was extracted directly from filter membranes, and PCR was used in the qualitative search of 32 antimicrobial resistance genes (ARGs). Selected genes (bla(CTX-M), bla(KPC), qnrB, and mcr-1) were enumerated by quantitative real-time PCR (qPCR). Twenty-six ARGs were detected in the qualitative ARGs search, while quantitative data showed a low variation of the ARG's relative abundance (RA) throughout the months, especially at the human hospital and the WWTP. At the WWTP, despite significantly reducing the absolute number of gene copies/L after each treatment stage (p < 0.05), slight increases (p > 0.05) in the RAs of genes bla(CTX-M), qnrB, and mcr-1 were observed in reused water (tertiary treatment) when compared with secondary effluent. Although the increase is not statistically significant, it is worth noting that there was some level of ARGs concentration after the disinfection process. No significant absolute or relative after-treatment quantification reductions were observed for any ARGs at the veterinary hospital or the pig farm. The spread of ARGs through sewage needs to be continuously addressed, because their release into natural environments may pose potential risks of exposure to resistant bacteria and impact local ecosystems.202438545908