Bubbles Expand the Dissemination of Antibiotic Resistance in the Aquatic Environment. - Related Documents




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855601.0000Bubbles Expand the Dissemination of Antibiotic Resistance in the Aquatic Environment. Antibiotic resistance is a global health challenge, and the COVID-19 pandemic has amplified the urgency to understand its airborne transmission. The bursting of bubbles is a fundamental phenomenon in natural and industrial processes, with the potential to encapsulate or adsorb antibiotic-resistant bacteria (ARB). However, there is no evidence to date for bubble-mediated antibiotic resistance dissemination. Here, we show that bubbles can eject abundant bacteria to the air, form stable biofilms over the air-water interface, and provide opportunities for cell-cell contact that facilitates horizontal gene transfer at and over the air-liquid interface. The extracellular matrix (ECM) on bacteria can increase bubble attachment on biofilms, increase bubble lifetime, and, thus, produce abundant small droplets. We show through single-bubble probe atomic force microscopy and molecular dynamics simulations that hydrophobic interactions with polysaccharides control how the bubble interacts with the ECM. These results highlight the importance of bubbles and its physicochemical interaction with ECM in facilitating antibiotic resistance dissemination and fulfill the framework on antibiotic resistance dissemination.202337379503
650210.9996A critical review on the occurrence of resistomes in the environment and their removal from wastewater using apposite treatment technologies: Limitations, successes and future improvement. Recent reports are pointing towards the potential increasing risks of resistomes in human host. With no permissible limit in sight, resistomes are continually multiplying at an alarming rate in the ecosystem, with a disturbing level in drinking water source. The morphology and chemical constituent of resistomes afford them to resist degradation, elude membrane and counter ionic charge, thereby, rendering both conventional and advanced water and wastewater treatment inefficient. Water and wastewater matrix may govern the propagation of individual resistomes sub-type, co-selection and specific interaction towards precise condition may have enhanced the current challenge. This review covers recent reports (2011-2019) on the occurrence of ARB/ARGs and ease of spread of resistance genes in the aquatic ecosystem. The contributions of water matrix to the spread and mitigation, treatment options, via bulk removal or capture, and intracellular and extracellular DNA lysis were discussed. A complete summary of recent occurrences of ARB/ARGs, fate after disinfection and optimum conditions of individual treatment technology or in tandem, including process limitations, with a brief assessment of removal or degradation mechanism were highlighted.202032224385
854820.9996Persulfate salts to combat bacterial resistance in the environment through antibiotic degradation and biofilm disruption. Antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) have become a critical topic among researchers because of the excessive use of antibiotics in human and animal health care. Globally, it poses a serious threat to human health and the environment. Antibiotics are often poorly metabolized, with 30-90 % excreted into the environment, contaminating aquatic and ground ecosystems, and fostering resistance. Advanced oxidation processes (AOPs), particularly sulfate radical-based AOPs (SR-AOPs), offer promising solutions for degrading antibiotics and resistant biofilms. Persulfate (PS) and Peroxymonosulfate (PMS) are key oxidants in these processes, generating sulfate and hydroxyl radicals when activated by heat, UV light, or transition metals. PS with a redox potential of E°=2.01 V is an affordable and effective oxidant. However, PS requires activation for the degradation of contaminants. PMS is stable across a broad pH range and produces both sulfate and hydroxyl radicals, allowing it to function independently without activation. Thus, PMS serving as a versatile agent for environmental treatment. This review broadly describes the degradation mechanisms of different classes of antibiotics and biofilms. Despite these promising developments, SR-AOPs still face challenges in managing complex wastewater systems, which often contain multiple pollutants. Moreover, gaps remain in understanding of the toxicity of reaction intermediates and in optimizing the large-scale application of these processes. Future research should focus on the in-situ generation of sulfate radicals, combining different activation methods to enhance degradation efficiency, and developing sustainable and cost-effective approaches for large-scale wastewater treatment.202540532556
854730.9996Molecular level removal of antibiotic resistant bacteria and genes: A review of interfacial chemical in advanced oxidation processes. As a kind of novel and persistent environmental pollutants, antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have been frequently detected in different aquatic environment, posing potential risks to public health and ecosystems, resulting in a biosecurity issue that cannot be ignored. Therefore, in order to control the spread of antibiotic resistance in the environment, advanced oxidation technology (such as Fenton-like, photocatalysis, electrocatalysis) has become an effective weapon for inactivating and eliminating ARB and ARGs. However, in the process of advanced oxidation technology, studying and regulating catalytic active sites at the molecular level and studying the adsorption and surface oxidation reactions between catalysts and ARGs can achieve in-depth exploration of the mechanism of ARGs removal. This review systematically reveals the catalytic sites and related mechanisms of catalytic antagonistic genes in different advanced oxidation processes (AOPs) systems. We also summarize the removal mechanism of ARGs and how to reduce the spread of ARGs in the environment through combining a variety of characterization methods. Importantly, the potential of various catalysts for removing ARGs in practical applications has also been recognized, providing a promising approach for the deep purification of wastewater treatment plants.202438447374
649940.9995From Conventional Disinfection to Antibiotic Resistance Control-Status of the Use of Chlorine and UV Irradiation during Wastewater Treatment. Extensive use of antibiotics for humans and livestock has led to an enhanced level of antibiotic resistance in the environment. Municipal wastewater treatment plants are regarded as one of the main sources of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in the aquatic environment. A significant amount of research has been carried out to understand the microbiological quality of wastewater with respect to its antibiotic resistance potential over the past several years. UV disinfection has primarily been used to achieve disinfection, including damaging DNA, but there has been an increasing use of chlorine and H(2)O(2)-based AOPs for targeting genes, including ARGs, considering the higher energy demands related to the greater UV fluences needed to achieve efficient DNA damage. This review focuses on some of the most investigated processes, including UV photolysis and chlorine in both individual and combined approaches and UV advanced oxidation processes (AOPs) using H(2)O(2). Since these approaches have practical disinfection and wastewater treatment applications globally, the processes are reviewed from the perspective of extending their scope to DNA damage/ARG inactivation in full-scale wastewater treatment. The fate of ARGs during existing wastewater treatment processes and how it changes with existing treatment processes is reviewed with a view to highlighting the research needs in relation to selected processes for addressing future disinfection challenges.202235162659
861150.9995Silver nanoparticles facilitate phage-borne resistance gene transfer in planktonic and microplastic-attached bacteria. The spread of bacteriophage-borne antibiotic resistance genes (ARGs) poses a realistic threat to human health. Nanomaterials, as important emerging pollutants, have potential impacts on ARGs dissemination in aquatic environments. However, little is known about its role in transductive transfer of ARGs mediated by bacteriophage in the presence of microplastics. Therefore, this study comprehensively investigated the influence of silver nanoparticles (AgNPs) on the transfer of bacteriophage-encoded ARGs in planktonic Escherichia coli and microplastic-attached biofilm. AgNPs exposure facilitated the phage transduction in planktonic and microplastic-attached bacteria at ambient concentration of 0.1 mg/L. Biological binding mediated by phage-specific recognition, rather than physical aggregation conducted by hydrophilicity and ζ-potential, dominated the bacterial adhesion of AgNPs. The aggregated AgNPs in turn resulted in elevated oxidative stress and membrane destabilization, which promoted the bacteriophage infection to planktonic bacteria. AgNPs exposure could disrupt colanic acid biosynthesis and then reduce the thickness of biofilm on microplastics, contributing to the transfer of phage-encoded ARGs. Moreover, the roughness of microplastics also affected the performance of AgNPs on the transductive transfer of ARGs in biofilms. This study reveals the compound risks of nanomaterials and microplastics in phage-borne ARGs dissemination and highlights the complexity in various environmental scenarios.202438452675
649860.9995Does light-based tertiary treatment prevent the spread of antibiotic resistance genes? Performance, regrowth and future direction. The common occurrence of antibiotic-resistance genes (ARGs) originating from pathogenic and facultative pathogenic bacteria pose a high risk to aquatic environments. Low removal of ARGs in conventional wastewater treatment processes and horizontal dissemination of resistance genes between environmental bacteria and human pathogens have made antibiotic resistance evolution a complex global health issue. The phenomenon of regrowth of bacteria after disinfection raised some concerns regarding the long-lasting safety of treated waters. Despite the inactivation of living antibiotic-resistant bacteria (ARB), the possibility of transferring intact and liberated DNA containing ARGs remains. A step in this direction would be to apply new types of disinfection methods addressing this issue in detail, such as light-based advanced oxidation, that potentially enhance the effect of direct light interaction with DNA. This study is devoted to comprehensively and critically review the current state-of-art for light-driven disinfection. The main focus of the article is to provide an insight into the different photochemical disinfection methods currently being studied worldwide with respect to ARGs removal as an alternative to conventional methods. The systematic comparison of UV/chlorination, UV/H(2)O(2), sulfate radical based-AOPs, photocatalytic processes and photoFenton considering their mode of action on molecular level, operational parameters of the processes, and overall efficiency of removal of ARGs is presented. An in-depth discussion of different light-dependent inactivation pathways, influence of DBP and DOM on ARG removal and the potential bacterial regrowth after treatment is presented. Based on presented revision the risk of ARG transfer from reactivated bacteria has been evaluated, leading to a future direction for research addressing the challenges of light-based disinfection technologies.202235031375
650370.9995The role of operating parameters and oxidative damage mechanisms of advanced chemical oxidation processes in the combat against antibiotic-resistant bacteria and resistance genes present in urban wastewater. An upsurge in the study of antibiotic resistance in the environment has been observed in the last decade. Nowadays, it is becoming increasingly clear that urban wastewater is a key source of antibiotic resistance determinants, i.e. antibiotic-resistant bacteria and antibiotic resistance genes (ARB&ARGs). Urban wastewater reuse has arisen as an important component of water resources management in the European Union and worldwide to address prolonged water scarcity issues. Especially, biological wastewater treatment processes (i.e. conventional activated sludge), which are widely applied in urban wastewater treatment plants, have been shown to provide an ideal environment for the evolution and spread of antibiotic resistance. The ability of advanced chemical oxidation processes (AOPs), e.g. light-driven oxidation in the presence of H(2)O(2), ozonation, homogeneous and heterogeneous photocatalysis, to inactivate ARB and remove ARGs in wastewater effluents has not been yet evaluated through a systematic and integrated approach. Consequently, this review seeks to provide an extensive and critical appraisal on the assessment of the efficiency of these processes in inactivating ARB and removing ARGs in wastewater effluents, based on recent available scientific literature. It tries to elucidate how the key operating conditions may affect the process efficiency, while pinpointing potential areas for further research and major knowledge gaps which need to be addressed. Also, this review aims at shedding light on the main oxidative damage pathways involved in the inactivation of ARB and removal of ARGs by these processes. In general, the lack and/or heterogeneity of the available scientific data, as well as the different methodological approaches applied in the various studies, make difficult the accurate evaluation of the efficiency of the processes applied. Besides the operating conditions, the variable behavior observed by the various examined genetic constituents of the microbial community, may be directed by the process distinct oxidative damage mechanisms in place during the application of each treatment technology. For example, it was shown in various studies that the majority of cellular damage by advanced chemical oxidation may be on cell wall and membrane structures of the targeted bacteria, leaving the internal components of the cells relatively intact/able to repair damage. As a result, further in-depth mechanistic studies are required, to establish the optimum operating conditions under which oxidative mechanisms target internal cell components such as genetic material and ribosomal structures more intensively, thus conferring permanent damage and/or death and preventing potential post-treatment re-growth.201829153875
963680.9995A comprehensive review on biodegradation of tetracyclines: Current research progress and prospect. The release of tetracyclines (TCs) in the environment is of significant concern because the residual antibiotics may promote resistance in pathogenic microorganisms, and the transfer of antibiotic resistance genes poses a potential threat to ecosystems. Microbial biodegradation plays an important role in removing TCs in both natural and artificial systems. After long-term acclimation, microorganisms that can tolerate and degrade TCs are retained to achieve efficient removal of TCs under the optimum conditions (e.g. optimal operational parameters and moderate concentrations of TCs). To date, cultivation-based techniques have been used to isolate bacteria or fungi with potential degradation ability. Moreover, the biodegradation mechanism of TCs can be unveiled with the development of chemical analysis (e.g. UPLC-Q-TOF mass spectrometer) and molecular biology techniques (e.g. 16S rRNA gene sequencing, multi-omics sequencing, and whole genome sequencing). In this review, we made an overview of the biodegradation of TCs in different systems, refined functional microbial communities and pure isolates relevant to TCs biodegradation, and summarized the biodegradation products, pathways, and degradation genes of TCs. In addition, ecological risks of TCs biodegradation were considered from the perspectives of metabolic products toxicity and resistance genes. Overall, this article aimed to outline the research progress of TCs biodegradation and propose future research prospects.202234995606
640690.9995The Environmental Lifecycle of Antibiotics and Resistance Genes: Transmission Mechanisms, Challenges, and Control Strategies. Antibiotics are widely used in modern medicine. However, as global antibiotic consumption rises, environmental contamination with antibiotics and antibiotic resistance genes (ARGs) is becoming a serious concern. The impact of antibiotic use on human health is now under scrutiny, particularly regarding the emergence of antibiotic-resistant bacteria (ARB) in the environment. This has heightened interest in technologies for treating ARGs, highlighting the need for effective solutions. This review traces the life cycle of ARB and ARGs driven by human activity, revealing pathways from antibiotic use to human infection. We address the mechanisms enabling resistance in ARB during this process. Beyond intrinsic resistance, the primary cause of ARB resistance is the horizontal gene transfer (HGT) of ARGs. These genes exploit mobile genetic elements (MGEs) to spread via conjugation, transformation, transduction, and outer membrane vesicles (OMVs). Currently, biological wastewater treatment is the primary pollution control method due to its cost-effectiveness. However, these biological processes can promote ARG propagation, significantly amplifying the environmental threat posed by antibiotics. This review also summarizes key mechanisms in the biological treatment of antibiotics and evaluates risks associated with major ARB/ARG removal processes. Our aim is to enhance understanding of ARB risks, their pathways and mechanisms in biotreatment, and potential biomedical applications for pollution control.202541011444
9642100.9995Towards the fate of antibiotics and the development of related resistance genes in stream biofilms. Antibiotics are ubiquitously found in natural surface waters and cause great harm to aquatic organisms. Stream biofilm is a complex and active community composed of algae, bacteria, fungi and other microorganisms, which mainly adheres to solid substances such as rocks and sediments. The durability and diverse structural and metabolic characteristics of biofilms make them a representative of microbial life in aquatic micrecosystems and can reflect major ecosystem processes. Microorganisms and extracellular polymeric substances in biofilms can adsorb and actively accumulate antibiotics. Therefore, biofilms are excellent biological indicators for detecting antibiotic in polluted aquatic environments, but the biotransformation potential of stream biofilms for antibiotics has not been fully explored in the aquatic environment. The characteristics of stream biofilm, such as high abundance and activity of bacterial community, wide contact area with pollutants, etc., which increases the opportunity of biotransformation of antibiotics in biofilm and contribute to bioremediation to improve ecosystem health. Recent studies have demonstrated that both exposure to high and sub-minimum inhibitory concentrations of antibiotics may drive the development of antibiotic resistance genes (ARGs) in natural stream biofilms, which are susceptible to the effects of antibiotic residues, microbial communities and mobile genetic elements, etc. On the basis of peer-reviewed papers, this review explores the distribution behavior of antibiotics in stream biofilms and the contribution of biofilms to the acquisition and spread of antibiotic resistance. Considering that antibiotics and ARGs alter the structure and ecological functions of natural microbial communities and pose a threat to river organisms and human health, our research findings provide comprehensive insights into the migration, transformation, and bioavailability of antibiotics in biofilms.202337454845
6409110.9995Bacterial perspectives on the dissemination of antibiotic resistance genes in domestic wastewater bio-treatment systems: beneficiary to victim. Domestic wastes, ranging from sewage and sludge to municipal solid waste, are usually treated in bioprocessing systems. These systems are regarded as main conduits for the elevated levels of antibiotic resistance genes (ARGs) observed in the environment. This paper mainly reviews recent studies on the occurrence and dynamics of ARGs in wastewater bio-treatment systems and discusses the ins and outs of ARG dissemination from the perspective of the microbial community. Our analysis shows that concentration of antibiotics through adsorption to microbial aggregates triggers the bacteria to acquire ARGs, which can be facilitated by the presence of mobile genetic elements. Notably, the acquisition and flow of ARGs during the rapid dissemination process is directed towards and for the best interests of the microbial community as a whole, and is influenced by surrounding nutrient levels, toxicant types, and sensitivities of the species in the prevailing antibiotic-stressed conditions. Furthermore, our review argues that predation of ARG-carrying bacteria by bacteriophages does periodically enhance the accessibility of ARGs to bacteria, which indirectly facilitates the recruitment of ARGs into environmental microbial communities.201829198067
6423120.9995Emerging soil contamination of antibiotics resistance bacteria (ARB) carrying genes (ARGs): New challenges for soil remediation and conservation. Soil plays a vital role as a nutrient source for microflora and plants in ecosystems. The accumulation and proliferation of antibiotics resistance bacteria (ARB) and antibiotics resistance genes (ARGs) causes emerging soil contamination and pollution, posing new challenges for soil remediation, recovery, and conservation. Fertilizer application in agriculture is one of the most important sources of ARB and ARGs contamination in soils. The recent existing techniques for the remediation of soil polluted with ARB and ARGs are very limited in terms of ARB and ARGs removal in soil. Bioelectrochemical remediation using bioelectrochemical systems such as microbial fuel cells and microbial electrolysis cells are promising technologies for the removal of ARB and ARGs in soil. Herein, diverse sources of ARB and ARGs in soil have been reviewed, their effects on soil microbial diversity have been analyzed, and the causes of ARB and ARGs rapid proliferation in soil are explained. Bioelectrochemical systems used for the remediation of soil contaminated with ARB and ARGs is still in its infancy stage and presents serious disadvantage and limits, therefore it needs to be well understood and implemented. In general, merging soil contamination of ARB and ARGs is an increasing concern threatening the soil ecosystem while the remediation technologies are still challenging. Efforts need to be made to develop new, effective, and efficient technologies for soil remediation and conservation to tackle the spread of ARB and ARGs and overcome the new challenges posed by ARB and ARGs contamination in soil.202336563979
8550130.9995Advances and solutions in biological treatment for antibiotic wastewater with resistance genes: A review. Biological treatment represents a fundamental component of wastewater treatment plants (WWTPs). The transmission of antibiotic resistance bacteria (ARB) and resistance genes (ARGs) occurred through the continuous migration and transformation, attributed to the residual presence of antibiotics in WWTPs effluent, posing a significant threat to the entire ecosystem. It is necessary to propose novel biological strategies to address the challenge of refractory contaminants, such as antibiotics, ARGs and ARB. This review summarizes the occurrence of antibiotics in wastewater, categorized by high and low concentrations. Additionally, current biological treatments used in WWTPs, such as aerobic activated sludge, anaerobic digestion, sequencing batch reactor (SBR), constructed wetland, membrane-related bioreactors and biological aerated filter (BAF) are introduced. In particular, because microorganisms are the key to those biological treatments, the effect of high and low concentration of antibiotics on microorganisms are thoroughly discussed. Finally, solutions involving functional bacteria, partial nitrification (PN)-Anammox and lysozyme embedding are suggested from the perspective of the entire biological treatment process. Overall, this review provides valuable insights for the simultaneous removal of antibiotics and ARGs in antibiotics wastewater.202439121628
6492140.9995Alternative, environmentally conscious approaches for removing antibiotics from wastewater treatment systems. Prevalence of antibiotic resistance in the environment is of critical concern from a public health perspective, with many human impacted environments showing increased incidence of antibiotic resistant bacteria. Wastewater treatment environments are of particular interest due to their high levels of antibiotic residuals, which can select for antibiotic resistance genes in bacteria. However, wastewater treatment plants are generally not designed to remove antibiotics from collected waste, and many of the currently proposed methods are unsafe for environmental use. This has prompted researchers to identify alternative environmentally safe methods for removing antibiotics from wastewater to be used in parallel with conventional wastewater treatment, as it is a potential strategy towards the mitigation of environmental antibiotic resistance selection. This paper reviews several methods developed to absorb and/or degrade antibiotics from aqueous solutions and wastewater biosolids, which includes ligninolytic fungi and ligninolytic enzymes, algae-driven photobioreactors and algae-activated sludge, and organically-sourced biochars.202133297145
6504150.9995Antibiotic Resistance in the Drinking Water: Old and New Strategies to Remove Antibiotics, Resistant Bacteria, and Resistance Genes. Bacterial resistance is a naturally occurring process. However, bacterial antibiotic resistance has emerged as a major public health problem in recent years. The accumulation of antibiotics in the environment, including in wastewaters and drinking water, has contributed to the development of antibiotic resistant bacteria and the dissemination of antibiotic resistance genes (ARGs). Such can be justified by the growing consumption of antibiotics and their inadequate elimination. The conventional water treatments are ineffective in promoting the complete elimination of antibiotics and bacteria, mainly in removing ARGs. Therefore, ARGs can be horizontally transferred to other microorganisms within the aquatic environment, thus promoting the dissemination of antibiotic resistance. In this review, we discuss the efficiency of conventional water treatment processes in removing agents that can spread/stimulate the development of antibiotic resistance and the promising strategies for water remediation, mainly those based on nanotechnology and microalgae. Despite the potential of some of these approaches, the elimination of ARGs remains a challenge that requires further research. Moreover, the development of new processes must avoid the release of new contaminants for the environment, such as the chemicals resulting from nanomaterials synthesis, and consider the utilization of green and eco-friendly alternatives such as biogenic nanomaterials and microalgae-based technologies.202235455389
9635160.9995The influence of antibiotics on the anammox process - a review. Anaerobic ammonium oxidation (anammox) is one of the most promising processes for the treatment of ammonium-rich wastewater. It is more effective, cheaper, and more environmentally friendly than the conventional process currently in use for nitrogen removal. Unfortunately, anammox bacteria are sensitive to various substances, including heavy metals and organic matter commonly found in the wastewater treatment plants (WWTPs). Of these deleterious substances, antibiotics are recognized to be important. For decades, the increasing consumption of antibiotics has led to the increased occurrence of antibiotics in the aquatic environment, including wastewater. One of the most important issues related to antibiotic pollution is the generation and transfer of antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs). Here, we will discuss the effect of short- and long-term exposure of the anammox process to antibiotic pollutants; with a special focus on the activity of the anammox bacteria, biomass properties, community structures, the presence of antibiotic resistance genes and combined effect of antibiotics with other substances commonly found in wastewater. Further, the defense mechanisms according to which bacteria adapt against antibiotic stress are speculated upon. This review aims to facilitate a better understanding of the influence of antibiotics and other co-pollutants on the anammox process and to highlight future avenues of research to target gaps in the knowledge.202234845633
6440170.9995Fate and transport of biological microcontaminants bound to microplastics in the soil environment. Microplastics, fragmented plastic particles with a maximum dimension <5 mm, are an emerging contaminant of concern that can also serve as a vector of other chemical and biological contaminants. Compared to chemical contaminants, the potential of microplastics to adsorb biological microcontaminants such as antibiotic resistance genes, small interference RNAs, and pathogenic viruses is not well understood. Many current microplastic studies are based in the aquatic environment (freshwater, seawater, and wastewater), even though the terrestrial environment is considered both an important sink and source of microplastics. Microplastics co-occur with biological microcontaminants in many terrestrial environments including agricultural soils, where biosolids containing both contaminants are often applied as a soil amendment. Recent research suggests that microplastics in these environments can increase gene persistence and flow, which could have unintended downstream consequences for environmental microbiome health and resilience. Antibiotic resistance genes and silencing RNAs bound to microplastics, for example, have the potential to increase resistance and alter gene expression in environmental bacteria, respectively. This review evaluates the sources and pathways of microplastics and biological microcontaminants in the terrestrial environment as well as potential sorption mechanisms that can encourage long-range transport and persistence. Novel sources of biological microcontaminants are considered, and the role of microplastics in promoting the persistence and flow of biological microcontaminants evaluated. Finally, future research directions are suggested to increase understanding of the mechanisms that drive the fate and transport of microplastic-biological microcontaminant complexes in the terrestrial environment and better inform risk management.202337247742
8613180.9995Insights into the role of extracellular polymeric substances (EPS) in the spread of antibiotic resistance genes. Antibiotic resistance genes (ARG) are prevalent in aquatic environments. Discharge from wastewater treatment plants is an important point source of ARG release into the environment. It has been reported that biological treatment processes may enhance rather than remove ARG because of their presence in sludge. Attenuation of ARG in biotechnological processes has been studied in depth, showing that many microorganisms can secrete complex extracellular polymeric substances (EPS). These EPS can serve as multifunctional elements of microbial communities, involving aspects, such as protection, structure, recognition, adhesion, and physiology. These aspects can influence the interaction between microbial cells and extracellular ARG, as well as the uptake of extracellular ARG by microbial cells, thus changing the transformative capability of extracellular ARG. However, it remains unclear whether EPS can affect horizontal ARG transfer, which is one of the main processes of ARG dissemination. In light of this knowledge gap, this review provides insight into the role of EPS in the transmission of ARGs; furthermore, the mechanism of ARG spread is analyzed, and the molecular compositions and functional properties of EPS are summarized; also, how EPS influence ARG mitigation is addressed, and factors impacting how EPS facilitate ARG during wastewater treatment are summarized. This review provides comprehensive insights into the role of EPS in controlling the transport and fate of ARG during biodegradation processes at the mechanistic level.202438169168
7442190.9995Potential impacts of disinfection processes on elimination and deactivation of antibiotic resistance genes during water and wastewater treatment. Antibiotic resistance genes (ARGs), in association with antibiotic resistant bacteria (ARB), have been identified as widespread contaminants of treated drinking waters and wastewaters. As a consequence, concerns have been raised that ARB or ARG transport between aquatic compartments may enhance the spread of antibiotic resistance amongst non-resistant bacterial communities by means of horizontal gene transfer processes. Most often, discussion of horizontal gene transfer focuses on the probable role of conjugative plasmid or transposon exchange, which requires live ARB donor cells. Conventional water and wastewater disinfection processes generally provide highly effective means for mitigating the transport of live ARB; thereby minimizing risks of conjugative gene transfer. However, even if ARB present in a treated water are fully inactivated during a disinfection process, the possibility remains that intact remnants of DNA contained within the resulting cell debris could still confer resistance genotypes to downstream bacterial populations by means of natural transformation and/or transduction, which do not require live donor cells. Thus, a systematic evaluation of the capability of common disinfection technologies to ensure the destruction of bacterial DNA, in addition to pathogen inactivation, seems warranted. With that objective in mind, this review seeks to provide a concise introduction to the significance of ARB and ARG occurrence in environmental systems, coupled with a review of the role that commonly used water and wastewater disinfection processes may play in minimizing ARG transport and dissemination.201222572858