# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 3346 | 0 | 1.0000 | Genes encoding antibiotic modifying enzymes conferring resistance against aminoglycosides in bacteria: Their identification and detection from wastewater. Global reporting of antibiotic resistant bacteria (ARB) bearing antibiotic resistance genes (ARGs) have increased in the past decade. Sewage systems act as breeding grounds for these pathogens. Dumping of untreated sewage effluent in river water systems have aided in their dissemination and spread. The molecular pathways circumventing antibiotics through ARGs is rising owing to overuse of these drugs. Use of aminoglycoside spectrum drugs has been increased exponentially. The genes providing resistance to these antibiotics are transferred through extra-chromosomal circular DNA elements. Polluted water bodies are ground zero for exchange of these genetic factors. Through literature survey, we shortlisted some clinically relevant genes which provide resistance against aminoglycosides and hold immense importance in present scenario. Initial screening for these genes was done on water samples collected from Swarna Rekha River channel in Gwalior District of Madhya Pradesh, India. A total of five identified genes were sequence verified using conventional PCR followed by targeted sequencing. Further, diagnostic platforms were designed for two reoccurring genes npmA & sat4(A) and their presence evaluated from wastewater samples collected from urban establishments of the district. Prevalence of these genes in sewage samples validated the broad impact of urban waste burden in polluting local water bodies. We were able to identify some indispensable and high risk aminoglycoside resistance providing genes, unreported in Indian context. This approach towards ARG screening could support risk assessment of future antibiotic resistance associated public health hazards. | 2025 | 39708933 |
| 4987 | 1 | 0.9998 | The Human Health Implications of Antibiotic Resistance in Environmental Isolates from Two Nebraska Watersheds. One Health field-based approaches are needed to connect the occurrence of antibiotics present in the environment with the presence of antibiotic resistance genes (ARGs) in Gram-negative bacteria that confer resistance to antibiotics important in for both veterinary and human health. Water samples from two Nebraska watersheds influenced by wastewater effluent and agricultural runoff were tested for the presence of antibiotics used in veterinary and human medicine. The water samples were also cultured to identify the bacteria present. Of those bacteria isolated, the Gram-negative rods capable of causing human infections had antimicrobial susceptibility testing and whole-genome sequencing (WGS) performed to identify ARGs present. Of the 211 bacterial isolates identified, 37 belonged to pathogenic genera known to cause human infections. Genes conferring resistance to beta-lactams, aminoglycosides, fosfomycins, and quinolones were the most frequently detected ARGs associated with horizontal gene transfer (HGT) in the watersheds. WGS also suggest recent HGT events involving ARGs transferred between watershed isolates and bacteria of human and animal origins. The results of this study demonstrate the linkage of antibiotics and bacterial ARGs present in the environment with potential human and/or veterinary health impacts. IMPORTANCE One health is a transdisciplinary approach to achieve optimal health for humans, animals, plants and their shared environment, recognizing the interconnected nature of health in these domains. Field based research is needed to connect the occurrence of antibiotics used in veterinary medicine and human health with the presence of antibiotic resistance genes (ARGs). In this study, the presence of antibiotics, bacteria and ARGs was determined in two watersheds in Nebraska, one with agricultural inputs and the other with both agricultural and wastewater inputs. The results presented in this study provide evidence of transfer of highly mobile ARG between environment, clinical, and animal-associated bacteria. | 2022 | 35311538 |
| 4983 | 2 | 0.9998 | Clinically Relevant β-Lactam Resistance Genes in Wastewater Treatment Plants. Antimicrobial resistance (AMR) is one of the largest global concerns due to its influence in multiple areas, which is consistent with One Health's concept of close interconnections between people, animals, plants, and their shared environments. Antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) circulate constantly in various niches, sediments, water sources, soil, and wastes of the animal and plant sectors, and is linked to human activities. Sewage of different origins gets to the wastewater treatment plants (WWTPs), where ARB and ARG removal efficiency is still insufficient, leading to their transmission to discharge points and further dissemination. Thus, WWTPs are believed to be reservoirs of ARGs and the source of spreading AMR. According to a World Health Organization report, the most critical pathogens for public health include Gram-negative bacteria resistant to third-generation cephalosporins and carbapenems (last-choice drugs), which represent β-lactams, the most widely used antibiotics. Therefore, this paper aimed to present the available research data for ARGs in WWTPs that confer resistance to β-lactam antibiotics, with a particular emphasis on clinically important life-threatening mechanisms of resistance, including extended-spectrum β-lactamases (ESBLs) and carbapenemases (KPC, NDM). | 2022 | 36360709 |
| 3469 | 3 | 0.9998 | Antibiotic resistance genes of emerging concern in municipal and hospital wastewater from a major Swedish city. The spread of antibiotic resistance among bacterial pathogens is to a large extent mediated by mobile antibiotic resistance genes (ARGs). The prevalence and geographic distribution of several newly discovered ARGs, as well as some clinically important ARGs conferring resistance to last resort antibiotics, are largely unknown. Targeted analysis of wastewater samples could allow estimations of carriage in the population connected to the sewers as well as release to the environment. Here we quantified ARGs conferring resistance to linezolid (optrA and cfr(A)) and colistin (mcr-1, -2, -3, -4 and -5) and the recently discovered gar (aminoglycoside ARG) and sul4 (sulphonamide ARG) in raw hospital and municipal wastewater as well as treated municipal wastewater during five years in a low antibiotic resistance prevalence setting (Gothenburg, Sweden). Additionally, variations in bacterial composition of the wastewaters characterized by 16S rRNA sequencing were related to the variations of the ARGs in an attempt to reveal if the presence of known or suspected bacterial host taxa could explain the presence of the ARGs in wastewater. The mcr-1, mcr-3, mcr-4, mcr-5, sul4 and gar genes were detected regularly in all types of wastewater samples while optrA and cfr(A) were detected only in hospital wastewater. The most abundant genes were mcr-3 and mcr-5, especially in municipal wastewater. The detection of optrA was restricted to a peak during one year. Most of the ARGs correlated with taxa previously described as bacterial hosts and associated with humans. Although some of the tentative hosts may include bacteria also thriving in wastewater environments, detection of the ARGs in the wastewaters could reflect their presence in the gut flora of the contributing populations. If so, they could already today or in the near future hinder treatment of bacterial infections in a setting where they currently are rarely targeted/detected during clinical surveillance. | 2022 | 34748849 |
| 3886 | 4 | 0.9998 | β-Lactam antibiotics and antibiotic resistance in Asian lakes and rivers: An overview of contamination, sources and detection methods. Lakes and rivers are sources of livelihood, food and water in many parts of the world. Lakes provide natural resources and valuable ecosystem services. These aquatic ecosystems are also vulnerable to known and new environmental pollutants. Emerging water contaminants are now being studied including antibiotics because of the global phenomenon on antibiotic resistance. β-Lactam antibiotics are widely used in human and animal disease prevention or treatment. The emergence of antibiotic resistance is a public health threat when bacteria become more resistant and infections consequently increase requiring treatment using last resort drugs that are more expensive. This review summarizes the key findings on the occurrence, contamination sources, and determination of β-lactam antibiotics and β-lactam antibiotic resistant bacteria and genes in the Asian lake and river waters. The current methods in the analytical measurements of β-lactam antibiotics in water involving solid-phase extraction and liquid chromatography-mass spectrometry are discussed. Also described is the determination of antibiotic resistance genes which is primarily based on a polymerase chain reaction method. To date, β-lactam antibiotics in the Asian aquatic environments are reported in the ng/L concentrations. Studies on β-lactam resistant bacteria and resistance genes were mostly conducted in China. The occurrence of these emerging contaminants is largely uncharted because many aquatic systems in the Asian region remain to be studied. Comprehensive investigations encompassing the environmental behavior of β-lactam antibiotics, emergence of resistant bacteria, transfer of resistance genes to non-resistant bacteria, multiple antibiotic resistance, and effects on aquatic biota are needed particularly in rivers and lakes that are eventual sinks of these water contaminants. | 2021 | 33571856 |
| 4986 | 5 | 0.9998 | Towards the standardization of Enterococcus culture methods for waterborne antibiotic resistance monitoring: A critical review of trends across studies. Antibiotic resistance is a major 21(st) century One Health (humans, animals, environment) challenge whose spread limits options to treat bacterial infections. There is growing interest in monitoring water environments, including surface water and wastewater, which have been identified as key recipients, pathways, and sources of antibiotic resistant bacteria (ARB). Aquatic environments also facilitate the transmission and amplification of ARB. Enterococcus spp. often carry clinically-important antibiotic resistance genes and are of interest as environmental monitoring targets. Enterococcus spp. are Gram-positive bacteria that are typically of fecal origin; however, they are also found in relevant environmental niches, with various species and strains that are opportunistic human pathogens. Although the value of environmental monitoring of antibiotic-resistant Enterococcus has been recognized by both national and international organizations, lack of procedural standardization has hindered generation of comparable data needed to implement integrated surveillance programs. Here we provide a comprehensive methodological review to assess the techniques used for the culturing and characterization of antibiotic-resistant Enterococcus across water matrices for the purpose of environmental monitoring. We analyzed 117 peer-reviewed articles from 33 countries across six continents. The goal of this review is to provide a critical analysis of (i) the various methods applied globally for isolation, confirmation, and speciation of Enterococcus isolates, (ii) the different methods for profiling antibiotic resistance among enterococci, and (iii) the current prevalence of resistance to clinically-relevant antibiotics among Enterococcus spp. isolated from various environments. Finally, we provide advice regarding a path forward for standardizing culturing of Enterococcus spp. for the purpose of antibiotic resistance monitoring in wastewater and wastewater-influenced waters within a global surveillance framework. | 2022 | 36466738 |
| 3719 | 6 | 0.9998 | Vancomycin-Resistant Enterococci and Bacterial Community Structure following a Sewage Spill into an Aquatic Environment. Sewage spills can release antibiotic-resistant bacteria into surface waters, contributing to environmental reservoirs and potentially impacting human health. Vancomycin-resistant enterococci (VRE) are nosocomial pathogens that have been detected in environmental habitats, including soil, water, and beach sands, as well as wildlife feces. However, VRE harboring vanA genes that confer high-level resistance have infrequently been found outside clinical settings in the United States. This study found culturable Enterococcus faecium harboring the vanA gene in water and sediment for up to 3 days after a sewage spill, and the quantitative PCR (qPCR) signal for vanA persisted for an additional week. Culturable levels of enterococci in water exceeded recreational water guidelines for 2 weeks following the spill, declining about five orders of magnitude in sediments and two orders of magnitude in the water column over 6 weeks. Analysis of bacterial taxa via 16S rRNA gene sequencing showed changes in community structure through time following the sewage spill in sediment and water. The spread of opportunistic pathogens harboring high-level vancomycin resistance genes beyond hospitals and into the broader community and associated habitats is a potential threat to public health, requiring further studies that examine the persistence, occurrence, and survival of VRE in different environmental matrices. IMPORTANCE: Vancomycin-resistant enterococci (VRE) are harmful bacteria that are resistant to the powerful antibiotic vancomycin, which is used as a last resort against many infections. This study followed the release of VRE in a major sewage spill and their persistence over time. Such events can act as a means of spreading vancomycin-resistant bacteria in the environment, which can eventually impact human health. | 2016 | 27422829 |
| 4989 | 7 | 0.9998 | A closer look on the variety and abundance of the faecal resistome of wild boar. Antimicrobial resistance (AMR) is a serious problem for public and animal health, and also for the environment. Monitoring and reporting the occurrence of AMR determinants and bacteria with the potential to disseminate is a priority for health surveillance programs around the world and critical to the One Health concept. Wildlife is a reservoir of AMR, and human activities can strongly influence their resistome. The main goal of this work was to study the resistome of wild boar faecal microbiome, one of the most important game species in Europe using metagenomic and culturing approaches. The most abundant genes identified by the high-throughput qPCR array encode mobile genetic elements, including integrons, which can promote the dissemination of AMR determinants. A diverse set of genes (n = 62) conferring resistance to several classes of antibiotics (ARGs), some of them included in the WHO list of critically important antimicrobials were also detected. The most abundant ARGs confer resistance to tetracyclines and aminoglycosides. The phenotypic resistance of E. coli and Enterococcus spp. were also investigated, and together supported the metagenomic results. As the wild boar is an omnivorous animal, it can be a disseminator of AMR bacteria and ARGs to livestock, humans, and the environment. This study supports that wild boar can be a key sentinel species in ecosystems surveillance and should be included in National Action Plans to fight AMR, adopting a One Health approach. | 2022 | 34710519 |
| 3477 | 8 | 0.9998 | Whole-genome sequencing characterization of silver-resistant bacteria from the outfall of wastewater treatment plants and effluent-receiving rivers. The excessive use of silver compounds has led to the environmental dissemination of silver resistance genes. However, little is known about the epidemiology of silver-resistant bacteria in the environment. Wastewater treatment plants (WWTPs) link the clinical settings with the natural environment and serve as a major pathway for silver entering the natural environment. However, their role in the dissemination of silver resistance genes remains unclear. This study investigated the characteristics of silver-resistant bacteria in the vicinity of four WWTPs to assess their environmental impact. Water and sediment samples were collected from the WWTP outfalls and downstream rivers. Among 22 silver-resistant strains obtained through plate screening, the majority were Klebsiella spp., followed by Escherichia spp. and Kluyvera spp. Notably, ST23 and ST2464 were the predominant sequence types (multilocus sequence typing) identified among the Klebsiella pneumoniae isolates. Antimicrobial susceptibility testing and whole-genome sequencing were performed to identify environmental heavy metal and antibiotic-resistant genes. Whole-genome sequencing revealed the presence of the sil and pco operons, which together formed the copper homeostasis and silver resistance island. The silver resistance gene sequences varied. Various heavy metal resistance genes, including mer and ars, were detected in the strains, as were a diverse array of plasmid types, including IncFIB(K) and repB(R1701), and fosA and β-lactamase encoding genes. Taken together, the findings underscore the coexistence of silver resistance genes with multiple heavy metal resistance genes in wastewater bacteria, highlighting the environmental implications of silver usage. Efforts should be directed toward restricting silver usage, improving WWTP purification methods to safeguard human and environmental health. IMPORTANCE: The misuse of silver compounds has led to an increasing presence of silver-resistant microorganisms in the environment, which cannot be completely eliminated in wastewater treatment plants, allowing them to enter the environment and pose risks to environmental safety and human health. However, research on the epidemiology of silver-resistant bacteria in wastewater and their whole-genome sequencing remains limited. Our findings explain that silver-resistant bacteria from the environment often possess resistance to other heavy metals, share genetic similarities, and possess the potential for widespread transmission. Furthermore, these bacteria may enter clinical settings through environmental pathways, posing a risk to human health. | 2025 | 40762474 |
| 3902 | 9 | 0.9998 | Integrons and antibiotic resistance genes in water-borne pathogens: threat detection and risk assessment. Antibiotic-resistant genes (ARGs) are regarded as emerging environmental pollutants and pose a serious health risk to the human population. Integrons are genetic elements that are involved in the spread of ARGs amongst bacterial species. They also act as reservoirs of these resistance traits, further contributing to the development of multi-drug resistance in several water-borne pathogens. Due to inter- and intra-species transfer, integrons are now commonly reported in important water-borne pathogens such as Vibrio, Campylobacter, Salmonella, Shigella, Escherichia coli and other opportunistic pathogens. These pathogens exhibit immense diversity in their resistance gene cassettes. The evolution of multiple novel and complex gene cassettes in integrons further suggests the selection and horizontal transfer of ARGs in multi-drug resistant bacteria. Thus, the detection and characterization of these integrons in water-borne pathogens, especially in epidemic and pandemic strains, is of the utmost importance. It will provide a framework in which health authorities can conduct improved surveillance of antibiotic resistance in our natural water bodies. Such a study will also be helpful in developing better strategies for the containment and cure of infections caused by these bacteria. | 2019 | 30990401 |
| 6569 | 10 | 0.9998 | Unveiling Rare Pathogens and Antibiotic Resistance in Tanzanian Cholera Outbreak Waters. The emergence of antibiotic resistance is a global health concern. Therefore, understanding the mechanisms of its spread is crucial for implementing evidence-based strategies to tackle resistance in the context of the One Health approach. In developing countries where sanitation systems and access to clean and safe water are still major challenges, contamination may introduce bacteria and bacteriophages harboring antibiotic resistance genes (ARGs) into the environment. This contamination can increase the risk of exposure and community transmission of ARGs and infectious pathogens. However, there is a paucity of information on the mechanisms of bacteriophage-mediated spread of ARGs and patterns through the environment. Here, we deploy Droplet Digital PCR (ddPCR) and metagenomics approaches to analyze the abundance of ARGs and bacterial pathogens disseminated through clean and wastewater systems. We detected a relatively less-studied and rare human zoonotic pathogen, Vibrio metschnikovii, known to spread through fecal--oral contamination, similarly to V. cholerae. Several antibiotic resistance genes were identified in both bacterial and bacteriophage fractions from water sources. Using metagenomics, we detected several resistance genes related to tetracyclines and beta-lactams in all the samples. Environmental samples from outlet wastewater had a high diversity of ARGs and contained high levels of blaOXA-48. Other identified resistance profiles included tetA, tetM, and blaCTX-M9. Specifically, we demonstrated that blaCTX-M1 is enriched in the bacteriophage fraction from wastewater. In general, however, the bacterial community has a significantly higher abundance of resistance genes compared to the bacteriophage population. In conclusion, the study highlights the need to implement environmental monitoring of clean and wastewater to inform the risk of infectious disease outbreaks and the spread of antibiotic resistance in the context of One Health. | 2023 | 37894148 |
| 4990 | 11 | 0.9998 | From soil to surface water: exploring Klebsiella 's clonal lineages and antibiotic resistance odyssey in environmental health. In the last decade, the presence of resistant bacteria and resistance genes in the environment has been a cause for increasing concern. However, understanding of its contribution to the spread of bacteria remains limited, as the scarcity of studies on how and under what circumstances the environment facilitates the development of resistance poses challenges in mitigating the emergence and spread of mobile resistance factors. Antimicrobial resistance in the environment is considered one of the biggest challenges and threats currently emerging. Thus, monitoring the presence of antibiotic-resistant species, in this particular case, Klebsiella spp., in the environment can be an added value for understanding the epidemiology of infections caused by Klebsiella spp.. Investigating soils and waters as potential reservoirs and transmission vehicles for these bacteria is imperative. Therefore, in this review, we aimed to describe the main genetic lineages present in environmental samples, as well as to describe the multidrug resistance strains associated with each environmental source. The studies analyzed in this review reported a high diversity of species and strains of Klebsiella spp. in the environment. K. pneumoniae was the most prevalent species, both in soil and water samples, and, as expected, often presented a multi-resistant profile. The presence of K. pneumoniae ST11, ST15, and ST147 suggests human and animal origin. Concerning surface waters, there was a great diversity of species and STs of Klebsiella spp. These studies are crucial for assessing the environmental contribution to the spread of pathogenic bacteria. | 2025 | 40012032 |
| 3885 | 12 | 0.9998 | Antibiotic resistance is widespread in urban aquatic environments of Rio de Janeiro, Brazil. Bacterial resistance to antibiotics has become a public health issue. Over the years, pathogenic organisms with resistance traits have been studied due to the threat they pose to human well-being. However, several studies raised awareness to the often disregarded importance of environmental bacteria as sources of resistance mechanisms. In this work, we analyze the diversity of antibiotic-resistant bacteria occurring in aquatic environments of the state of Rio de Janeiro, Brazil, that are subjected to distinct degrees of anthropogenic impacts. We access the diversity of aquatic bacteria capable of growing in increasing ampicillin concentrations through 16S rRNA gene libraries. This analysis is complemented by the characterization of antibiotic resistance profiles of isolates obtained from urban aquatic environments. We detect communities capable of tolerating antibiotic concentrations up to 600 times higher than the clinical levels. Among the resistant organisms are included potentially pathogenic species, some of them classified as multiresistant. Our results extend the knowledge of the diversity of antibiotic resistance among environmental microorganisms and provide evidence that the diversity of drug-resistant bacteria in aquatic habitats can be influenced by pollution. | 2014 | 24821495 |
| 4988 | 13 | 0.9998 | Oh, deer! How worried should we be about the diversity and abundance of the faecal resistome of red deer? The emergence of antimicrobial resistance (AMR) is a global threat to public health. Antimicrobials are used in animal production and human medicine, which contribute to the circulation of antibiotic resistance genes (ARGs) in the environment. Wildlife can be reservoirs of pathogens and resistant bacteria. Furthermore, anthropogenic pressure can influence their resistome. This work aimed to study the AMR of the faecal microbiome of red deer, one of the most important game species in Europe. To this end, a high-throughput qPCR approach was employed to screen a high number of ARGs and the antimicrobial susceptibility of indicator bacteria was determined. Several genes that confer resistance to different classes of antibiotics were identified, with the most abundant being tetracycline ARGs. Other genes were also present that are considered current and future threats to human health, and some of these were relatively abundant. Multidrug-resistant E. coli and Enterococcus spp. were isolated, although the overall level of antibiotic resistance was low. These results highlight the pressing need to know the origin and transmission of AMR in wildlife. Thus, and considering the One Health concept, studies such as this one shows the need for surveillance programs to prevent the spread of drug-resistant strains and ARGs. | 2022 | 35151727 |
| 3297 | 14 | 0.9998 | Antibiotic Resistance in Wastewater Treatment Plants and Transmission Risks for Employees and Residents: The Concept of the AWARE Study. Antibiotic resistance has become a serious global health threat. Wastewater treatment plants may become unintentional collection points for bacteria resistant to antimicrobials. Little is known about the transmission of antibiotic resistance from wastewater treatment plants to humans, most importantly to wastewater treatment plant workers and residents living in the vicinity. We aim to deliver precise information about the methods used in the AWARE (Antibiotic Resistance in Wastewater: Transmission Risks for Employees and Residents around Wastewater Treatment Plants) study. Within the AWARE study, we gathered data on the prevalence of two antibiotic resistance phenotypes, ESBL-producing E. coli and carbapenemase-producing Enterobacteriaceae, as well as on their corresponding antibiotic resistance genes isolated from air, water, and sewage samples taken from inside and outside of different wastewater treatment plants in Germany, the Netherlands, and Romania. Additionally, we analysed stool samples of wastewater treatment plant workers, nearby residents, and members of a comparison group living ≥1000 m away from the closest WWTP. To our knowledge, this is the first study investigating the potential spread of ESBL-producing E. coli, carbapenemase-producing Enterobacteriaceae, and antibiotic resistance genes from WWTPs to workers, the environment, and nearby residents. Quantifying the contribution of different wastewater treatment processes to the removal efficiency of ESBL-producing E. coli, carbapenemase-producing Enterobacteriaceae, and antibiotic resistance genes will provide us with evidence-based support for possible mitigation strategies. | 2021 | 33919179 |
| 3478 | 15 | 0.9997 | Bacterial plasmid-mediated quinolone resistance genes in aquatic environments in China. Emerging antimicrobial resistance is a major threat to human's health in the 21(st) century. Understanding and combating this issue requires a full and unbiased assessment of the current status on the prevalence of antimicrobial resistance genes and their correlation with each other and bacterial groups. In aquatic environments that are known reservoirs for antimicrobial resistance genes, we were able to reach this goal on plasmid-mediated quinolone resistance (PMQR) genes that lead to resistance to quinolones and possibly also to the co-emergence of resistance to β-lactams. Novel findings were made that qepA and aac-(6')-Ib genes that were previously regarded as similarly abundant with qnr genes are now dominant among PMQR genes in aquatic environments. Further statistical analysis suggested that the correlation between PMQR and β-lactam resistance genes in the environment is still weak, that the correlations between antimicrobial resistance genes could be weakened by sufficient wastewater treatment, and that the prevalence of PMQR has been implicated in environmental, pathogenic, predatory, anaerobic, and more importantly, human symbiotic bacteria. This work provides a comprehensive analysis of PMQR genes in aquatic environments in Jinan, China, and provides information with which combat with the antimicrobial resistance problem may be fought. | 2017 | 28094345 |
| 4991 | 16 | 0.9997 | Genomic and metagenomic analysis reveals shared resistance genes and mobile genetic elements in E. coli and Klebsiella spp. isolated from hospital patients and hospital wastewater at intra- and inter-genus level. Antimicrobial resistance (AMR) is a global problem that gives serious cause for concern. Hospital wastewater (HWW) is an important link between the clinical setting and the natural environment, and an escape route for pathogens that cause hospital infections, including urinary tract infections (UTI). Bacteria of the genera Escherichia and Klebsiella are common etiological factors of UTI, especially in children, and they can cause short-term infections, as well as chronic conditions. ESBL-producing Escherichia and Klebsiella have also emerged as potential indicators for estimating the burden of antimicrobial resistance under environmental conditions and the spread of AMR between clinical settings and the natural environment. In this study, whole-genome sequencing and the nanopore technology were used to analyze the complete genomes of ESBL-producing E.coli and Klebsiella spp. and the HWW metagenome, and to characterize the mechanisms of AMR. The similarities and differences in the encoded mechanisms of AMR in clinical isolates (causing UTI) and environmental strains (isolated from HWW and the HWW metagenome) were analyzed. Special attention was paid to the genetic context and the mobility of antibiotic resistance genes (ARGs) to determine the common sources and potential transmission of these genes. The results of this study suggest that the spread of drug resistance from healthcare facilities via HWW is not limited to the direct transmission of resistant clonal lines that are typically found in the clinical setting, but it also involves the indirect transfer of mobile elements carrying ARGs between bacteria colonizing various environments. Hospital wastewater could offer a supportive environment for plasmid evolution through the insertion of new ARGs, including typical chromosomal regions. These results indicate that interlined environments (hospital patients - HWW) should be closely monitored to evaluate the potential transmission routes of drug resistance in bacteria. | 2024 | 39038407 |
| 6574 | 17 | 0.9997 | Exploiting microplastics and the plastisphere for the surveillance of human pathogenic bacteria discharged into surface waters in wastewater effluent. Discharge from wastewater treatment plants (WWTPs) is a well-characterised source of human pathogens and antimicrobial resistance genes entering the environment. However, determining whether pathogens released from effluent into surface waters are viable, and consequently pose a risk to human health, is hindered by the use of transient grab-sampling monitoring approaches. Here we present a novel surveillance system using low-cost microparticles (polyethylene, cork and rubber) deployed upstream and downstream of a WWTP effluent pipe, that exploits the ability of bacterial pathogens to form biofilms. Using quantitative culture-based and molecular methods, viable E. coli, Klebsiella spp., Citrobacter spp., and Enterococcus spp. were identified after only 24-hour of deployment. Moreover, these pathogens were continually present at each timepoint (2, 4, 6, 8, 10, 14 and 23 days) as biofilm communities matured, with all pathogens detected at higher concentrations downstream of the WWTP effluent pipe. Long-read whole genome sequencing revealed a suite of plasmids, virulence genes and antimicrobial resistance genes in bacterial pathogens isolated from biofilms formed downstream of the effluent pipe. Furthermore, recognising that pathogens are typically present at proportionally low concentrations within mixed biofilm communities, total biofilm pathogenicity was confirmed using a Galleria mellonella infection model. Full-length 16S rRNA gene sequencing revealed that human pathogens present in microplastic biofilms (the 'plastisphere') dominated the microbial community of infected G. mellonella larvae within 24 hr, suggesting these bacteria remained highly virulent. Overall, this study demonstrated the efficacy of an easy-to-deploy system for the surveillance and rapid detection of pathogenic bacteria being discharged from point-source pollution. We envisage that if used as part of an integrated environmental management approach, this approach could help to reduce the public and environmental health risks of human pathogens and antimicrobial resistance genes, by monitoring viable human pathogens entering surface waters. | 2025 | 40184703 |
| 6567 | 18 | 0.9997 | Freshwater environments as reservoirs of antibiotic resistant bacteria and their role in the dissemination of antibiotic resistance genes. Freshwater environments are susceptible to possible contamination by residual antibiotics that are released through different sources, such as agricultural runoffs, sewage discharges and leaching from nearby farms. Freshwater environment can thus become reservoirs where an antibiotic impact microorganisms, and is an important public health concern. Degradation and dilution processes are fundamental for predicting the actual risk of antibiotic resistance dissemination from freshwater reservoirs. This study reviews major approaches for detecting and quantifying antibiotic resistance bacteria (ARBs) and genes (ARGs) in freshwater and their prevalence in these environments. Finally, the role of dilution, degradation, transmission and the persistence and fate of ARB/ARG in these environments are also reviewed. Culture-based single strain approaches and molecular techniques that include polymerase chain reaction (PCR), quantitative polymerase chain reaction (qPCR) and metagenomics are techniques for quantifying ARB and ARGs in freshwater environments. The level of ARBs is extremely high in most of the river systems (up to 98% of the total detected bacteria), followed by lakes (up to 77% of the total detected bacteria), compared to dam, pond, and spring (<1%). Of most concern is the occurrence of extended-spectrum β-lactamase producing Enterobacteriaceae, methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococcus (VRE), which cause highly epidemic infections. Dilution and natural degradation do not completely eradicate ARBs and ARGs in the freshwater environment. Even if the ARBs in freshwater are effectively inactivated by sunlight, their ARG-containing DNA can still be intact and capable of transferring resistance to non-resistant strains. Antibiotic resistance persists and is preserved in freshwater bodies polluted with high concentrations of antibiotics. Direct transmission of indigenous freshwater ARBs to humans as well as their transitory insertion in the microbiota can occur. These findings are disturbing especially for people that rely on freshwater resources for drinking, crop irrigation, and food in form of fish. | 2019 | 31465907 |
| 3888 | 19 | 0.9997 | A Systematic Review of Culture-Based Methods for Monitoring Antibiotic-Resistant Acinetobacter, Aeromonas, and Pseudomonas as Environmentally Relevant Pathogens in Wastewater and Surface Water. PURPOSE OF REVIEW: Mounting evidence indicates that habitats such as wastewater and environmental waters are pathways for the spread of antibiotic-resistant bacteria (ARB) and mobile antibiotic resistance genes (ARGs). We identified antibiotic-resistant members of the genera Acinetobacter, Aeromonas, and Pseudomonas as key opportunistic pathogens that grow or persist in built (e.g., wastewater) or natural aquatic environments. Effective methods for monitoring these ARB in the environment are needed to understand their influence on dissemination of ARB and ARGs, but standard methods have not been developed. This systematic review considers peer-reviewed papers where the ARB above were cultured from wastewater or surface water, focusing on the accuracy of current methodologies. RECENT FINDINGS: Recent studies suggest that many clinically important ARGs were originally acquired from environmental microorganisms. Acinetobacter, Aeromonas, and Pseudomonas species are of interest because their ability to persist and grow in the environment provides opportunities to engage in horizontal gene transfer with other environmental bacteria. Pathogenic strains of these organisms resistant to multiple, clinically relevant drug classes have been identified as an urgent threat. However, culture methods for these bacteria were generally developed for clinical samples and are not well-vetted for environmental samples. The search criteria yielded 60 peer-reviewed articles over the past 20 years, which reported a wide variety of methods for isolation, confirmation, and antibiotic resistance assays. Based on a systematic comparison of the reported methods, we suggest a path forward for standardizing methodologies for monitoring antibiotic resistant strains of these bacteria in water environments. | 2023 | 36821031 |