Potential Environmental and Human Health Risks Caused by Antibiotic-Resistant Bacteria (ARB), Antibiotic Resistance Genes (ARGs) and Emerging Contaminants (ECs) from Municipal Solid Waste (MSW) Landfill

Monitoring Antibiotic Pollutants in Water Using Electrochemical Techniques: A Detailed Review

This review article examines the application of electrochemical methods for detecting four prevalent antibiotics - azithromycin (AZM), amoxicillin (AMX), tetracycline (TC), and ciprofloxacin (CIP) - in environmental monitoring. Although, antibiotics are essential to contemporary treatment, their widespread usage has contaminated the environment and given rise to antibiotic resistance. Electrochemical techniques offer sensitive, rapid, and cost-effective solutions for monitoring these antibiotics, addressing the limitations of traditional methods. The review provides a comprehensive analysis of various electrochemical approaches, including voltammetry, amperometry, photoelectrochemical and so on, highlighting their principles, advantages, and limitations. Key findings underscore the effectiveness of these methods in detecting antibiotics at trace levels in complex environmental matrices. Implications for environmental health and policy are discussed, emphasizing the importance of reliable detection techniques in mitigating antibiotic resistance and safeguarding ecosystems. Lastly, the article outlines future research directions aimed at enhancing the sensitivity, selectivity, and field-applicability of electrochemical sensors, thus advancing their utility in environmental monitoring and public health protection.

Antibiotic resistance in urban soils: Dynamics and mitigation strategies

Antibiotic resistance (AR) is a critical global health issue with significant clinical and economic implications. AR occurs when microorganisms develop mechanisms to withstand the effects of antibiotics, reducing treatment efficacy and increasing the risk of mortality and healthcare costs. While the connection between antibiotic use in clinical and agricultural settings and the emergence of AR is well-established, the role of urban soils as reservoirs and spreaders of AR is underexplored. This review examines the complex dynamics of AR in urban soils, highlighting the various sources of antibiotics, including domestic wastewater, industrial effluents, urban agricultural practices, but also microplastics and domestic animal excrements. The selective pressure exerted by these anthropogenic sources promotes the proliferation of antibiotic-resistant bacteria, particularly through horizontal gene transfer, which facilitates the transmission of resistance genes among soil microorganisms in urban environments. About that, the presence of antibiotics in urban soils poses a significant threat to public health by potentially transferring resistance genes to human pathogens through multiple pathways, including direct contact, food consumption, and water ingestion. Furthermore, AR in urban soils disrupts microbial community dynamics, impacting soil fertility, plant growth, and overall environmental quality. Therefore, this review aims to address gaps in understanding AR in urban soils, offering insights into its implications for human health and ecosystem integrity. By identifying these gaps and suggesting evidence-based strategies, this review proposes valid and sustainable solutions to mitigate and counteract the spread of AR in urban environments.

Aptamer regulated peroxidase-like activity of cobalt oxyhydroxide nanosheets for colorimetric detection of kanamycin

A straightforward label-free colorimetric aptasensor utilizing the aptamer-enhanced peroxidase-like activity of cobalt oxyhydroxide (CoOOH) nanosheets has been established for kanamycin detection. In the kanamycin-free state, aptamers adsorb onto the CoOOH surface through electrostatic forces, enhancing the peroxidase-like activity of CoOOH and thereby resulting in a strong absorption signal and a yellow hue in 3,3',5,5'-tetramethylbenzidine (TMB) upon termination of the reaction with a stop solution. Conversely, upon the introduction of kanamycin, aptamers and CoOOH nanosheets compete for binding to kanamycin, resulting in a significant decrease in the number of aptamers bound to CoOOH. As a result, the activity of CoOOH diminishes, leading to a corresponding reduction in coloration and absorbance of the solution. Hence, the quantitative determination of kanamycin could be realized by analyzing the absorbance variations. Under optimal conditions, the aptasensor demonstrated high sensitivity and specificity, with a linear detection range from 500 nM to 5 µM and a detection limit as low as 54.6 nM. Moreover, the aptasensor effectively identified kanamycin in river water samples, achieving a recovery rate between 91.7% and 102.1%. This approach offers good practicability and provides a novel platform for kanamycin detection in environmental samples.

Healthcare waste management and antimicrobial resistance: a critical review

The rapid growth of populations and urbanization has led to a significant increase in healthcare waste, posing serious health risks. A search on Google Scholar identified seven relevant articles from Ethiopia that examine the relationship between improper waste management in healthcare facilities (HCFs) and the rise of antimicrobial resistance (AMR) genes. This review aims to highlight key concepts, evidence sources, and knowledge gaps specific to the Ethiopian context. The unsafe disposal of antibiotics through leaks and solid waste has contributed to what some are calling a 'silent pandemic,' raising concerns about emerging infectious diseases. Studies have revealed alarming rates of infectious agents and AMR in healthcare wastewater. Isolates of C. jejuni, Escherichia coli, Enterococcus faecalis, and Enterococcus faecium from various healthcare waste sites in Ethiopia demonstrate high levels of AMR genes. Additionally, research indicates that HCFs produce significant amounts of waste, with high per-person daily waste production rates. Leachate from landfills containing this waste can negatively affect soil health, biological activity, water quality, agriculture, animal health, and human well-being. To mitigate these risks, effective waste management practices and the promotion of alternative antimicrobial use are essential strategies for reducing the emergence of pandemic diseases in developing countries.

Supporting the investigation of health outcomes due to airborne emission by different approaches: current evidence for the waste incineration sector

Life cycle assessment (LCA) along with a survey on epidemiologic and oxidative potential studies was used for analysing the current evidence of the impact of airborne emissions from municipal solid waste incineration (MSWI) on human health. The correspondence among investigated health outcomes and pollutants was discussed based on the Chemical Abstract Service (CAS) and the International Agency for Research on Cancer (IARC). LCA indicated the ability of MSWI in avoiding human health impact, about - 2 × 10-4 DALY/tonne together with avoided emissions of particulate matter (PM) and resource depletion, about - 2.5 × 10-3 kg Sbeq/tonne and about - 0.11 kg PM2.5 eq/tonne, respectively. Positive emissions were detected for greenhouses (about 900 kg CO2eq/tonne) and ecotoxicity (about 15,000 CTUe/tonne). Epidemiologic studies performed on population exposed to MSWI reported quite contrasting results. In some of these, hazard ratio (HR) ranging from about 0.7 to 2.2 was reported concerning the incidence of stomach, liver, breast and bladder cancer. Larger agreement was detected concerning the incidence of larynx and lung cancer with HR ranging from about 1 to about 2.6. Direct causal nexuses were not definitively identified. Oxidative potential of PM was characterized by a high Pearson correlation > 0.8 to the presence of CrVI, Cu and Zn. These heavy metals were also identified by both CAS and IARC as toxic (i.e. Cu and Zn) and cancerous (i.e. CrVI) substances affecting the organs of both respiratory and digestive apparatus. In general, even if more research is necessary, LCA, oxidative potential and the epidemiologic survey results showed a high level of accordance. This suggests their integrated exploitation for supporting the investigation of both direct and indirect consequences on environment and health related to waste incineration for both retrospective and predictive studies.

Occurrence and dissemination of antibiotics and antibiotic resistance in aquatic environment and its ecological implications: a review

The occurrence of antibiotics and antibiotic-resistant bacteria (ARBs), genes (ARGs), and mobile genetic elements (MGEs) in aquatic systems is growing global public health concern. These emerging micropollutants, stemming from improper wastewater treatment and disposal, highlight the complex and evolving nature of environmental pollution. Current literature reveals potential biases, such as a geographical focus on specific regions, leading to an insufficient understanding of the global distribution and dynamics of antibiotic resistance in aquatic systems. There is methodological inconsistency across studies, making it challenging to compare findings. Potential biases include sample collection inconsistencies, detection sensitivity variances, and data interpretation variability. Gaps in understanding include the need for comprehensive, standardized long-term monitoring programs, elucidating the environmental fate and transformation of antibiotics and resistance genes. This review summarizes current knowledge on the occurrence and dissemination of emerging micropollutants, their ecological impacts, and the global health implications of antimicrobial resistance. It highlights the need for interdisciplinary collaborations among researchers, policymakers, and stakeholders to address the challenges posed by antibiotic resistance in aquatic resistance in aquatic systems effectively. This review highlights widespread antibiotic and antibiotic resistance in aquatic environment, driven by human and agricultural activities. It underscores the ecological consequences, including disrupted microbial communities and altered ecosystem functions. The findings call for urgent measures to mitigate antibiotics pollution and manage antibiotic resistance spread in water bodies.

High Prevalence of Antibiotic Resistance Bacteria Isolated From Bahir Dar City Municipal Solid Waste Dumpsite, North West Ethiopia

The emergence and spread of antibiotic resistance (ABR) have been a public health challenge globally. The burden is even higher in low-income countries where there is a lack of appropriate healthcare systems, and inappropriate antibiotic disposal practices and utilization. Due to poor solid waste disposal practices in developing nations, municipal solid waste dumpsite (MSWDS) can be a reservoir for ABR bacteria. However, only a few studies demonstrated the prevalence of ABR in non-clinical environments such as MSWDS. This study assessed the prevalence of ABR bacteria at Bahir Dar City MSWDS, to understand the public health risks related to poor solid waste disposal systems. Nine soil samples were collected from the dumpsite. Bacteria were isolated, identified and tested for ABR. Seventy-one distinct colonies were isolated from all samples and identified into 10 bacterial genera based on morphological features and biochemical tests. For ABR tests, gentamicin (GN, 10 μg), streptomycin (ST, 30 μg), tetracycline (TE, 30 μg), ciprofloxacin (CIP, 5 μg), nalidixic acid (NAA, 30 μg), sulfonamide (SA, 250 μg), chloramphenicol (C, 30 μg), erythromycin (E, 15 μg), vancomycin (V, 30 μg), and amoxicillin (AMX, 25 μg) were used. The most frequently isolated bacteria were Staphylococcus (23%) followed by Escherichia species (17%). Ten isolates related to Bacillus spp. were excluded from the antibiotic sensitivity test as there is no standard regarding this genus in the Clinical and Laboratory Standards Institute. The overall antibiotic résistance rate was 95.08%, and most isolates were found to be resistant to amoxicillin (100%), nalidixic acid (75.5%), and vancomycin (75%). Substantial proportions of the isolates were also resistant to tetracycline (55.35%), streptomycin (54.5%), and sulfonamide (50%). The overall multidrug resistance (MDR) rate was 36.06%. This high level of ABR calls for urgent intervention in waste management systems and regular surveillance programs.

Antibiotic resistome in landfill leachate and impact on groundwater

Landfill leachate is a hotspot in antibiotic resistance development. However, little is known about antibiotic resistome and host pathogens in leachate and their effects on surrounding groundwater. Here, metagenomic sequencing was used to explore profiles, host bacteria, environmental risks and influencing factors of antibiotic resistome in raw and treated leachate and surrounding groundwater of three landfills. Results showed detection of a total of 324 antibiotic resistance genes (ARGs). The ARGs conferring resistance to multidrug (8.8 %-25.7 %), aminoglycoside (13.1 %-39.2 %), sulfonamide (10.0 %-20.9 %), tetracycline (5.7 %-34.4 %) and macrolide-lincosamide-streptogramin (MLS, 5.3 %-29.5 %) were dominant in raw leachate, while multidrug resistance genes were the major ARGs in treated leachate (64.1 %-83.0 %) and groundwater (28.7 %-76.6 %). Source tracking analysis suggests non-negligible influence of leachate on the ARGs in groundwater. The pathogens including Acinetobacter pittii, Pseudomonas stutzeri and P. alcaligenes were the major ARG-carrying hosts. Variance partitioning analysis indicates that the microbial community, abiotic variables and their interaction contributed most to the antibiotic resistance development. Our results shed light on the dissemination and driving mechanisms of ARGs from leachate to the groundwater, indicating that a comprehensive risk assessment and efficient treatment approaches are needed to deal with ARGs in landfill leachate and nearby groundwater. ENVIRONMENTAL IMPLICATIONS: Antibiotic resistance genes are found abundant in the landfill sites, and these genes could be disseminated into groundwater via leaching of wastewater and infiltration of leachate. This results in deterioration of groundwater quality and human health risks posed by these ARGs and related pathogens. Thus measures should be taken to minimize potential negative impacts of landfills on the surrounding environment.

Ecotoxicological impacts of landfill sites: Towards risk assessment, mitigation policies and the role of artificial intelligence

Waste disposal in landfills remains a global concern. Despite technological developments, landfill leachate poses a hazard to ecosystems and human health since it acts as a secondary reservoir for legacy and emerging pollutants. This study provides a systematic and scientometric review of the nature and toxicity of pollutants generated by landfills and means of assessing their potential risks. Regarding human health, unregulated waste disposal and pathogens in leachate are the leading causes of diseases reported in local populations. Both in vitro and in vivo approaches have been employed in the ecotoxicological risk assessment of landfill leachate, with model organisms ranging from bacteria to birds. These studies demonstrate a wide range of toxic effects that reflect the complex composition of leachate and geographical variations in climate, resource availability and management practices. Based on bioassay (and other) evidence, categories of persistent chemicals of most concern include brominated flame retardants, per- and polyfluorinated chemicals, pharmaceuticals and alkyl phenol ethoxylates. However, the emerging and more general literature on microplastic toxicity suggests that these particles might also be problematic in leachate. Various mitigation strategies have been identified, with most focussing on improving landfill design or leachate treatment, developing alternative disposal methods and reducing waste volume through recycling or using more sustainable materials. The success of these efforts will rely on policies and practices and their enforcement, which is seen as a particular challenge in developing nations and at the international (and transboundary) level. Artificial intelligence and machine learning afford a wide range of options for evaluating and reducing the risks associated with leachates and gaseous emissions from landfills, and various approaches tested or having potential are discussed. However, addressing the limitations in data collection, model accuracy, real-time monitoring and our understanding of environmental impacts will be critical for realising this potential.

Reducing transmission of high-risk antibiotic resistance genes in whole-crop corn silage through lactic acid bacteria inoculation and increasing ensiling temperature

The microbial hosts of antibiotic resistance genes (ARGs) found epiphytically on plant materials could grow and flourish during silage fermentation. This study employed metagenomic analysis and elucidated the occurrence and transmission mechanisms of ARGs and their microbial hosts in whole-crop corn silage inoculated with homofermentative strain Lactiplantibacillus plantarum or heterofermentative strain Lentilactobacillus buchneri ensiled under different temperature (20 and 30 °C). The results revealed that the corn silage was dominated by Lactobacillus, Leuconostoc, Lentilactobacillus, and Latilactobacillus. Both the ensiling temperature and inoculation had greatly modified the silage microbiota. However, regardless of the ensiling temperature, L. buchneri had significantly higher ARGs, while it only exhibited significantly higher mobile genetic elements (MGEs) in low temperature treatments. The microbial community of the corn silage hosted highly diverse form of ARGs, which were primarily MacB, RanA, bcrA, msbA, TetA (58), and TetT and mainly corresponded to macrolides and tetracyclines drug classes. Plasmids were identified as the most abundant MGEs with significant correlation with some high-risk ARGs (tetM, TolC, mdtH, and NorA), and their abundances have been reduced by ensiling process. Furthermore, higher temperature and L. buchneri reduced abundances of high-risk ARGs by modifying their hosts and reduced their transmission in the silage. Therefore, ensiling, L. buchneri inoculation and higher storage temperature could improve the biosafety of corn silage.

Landfill leachate a potential challenge towards sustainable environmental management

The increasing amount of waste globally has led to a rise in the use of landfills, causing more pollutants to be released through landfill leachate. This leachate is a harmful mix formed from various types of waste at a specific site, and careful disposal is crucial to prevent harm to the environment. Understanding the physical and chemical properties, age differences, and types of landfills is essential to grasp how landfill leachate behaves in the environment. The use of Sustainable Development Goals (SDGs) in managing leachate is noticeable, as applying these goals directly is crucial in reducing the negative effects of landfill leachate. This detailed review explores the origin of landfill leachate, its characteristics, global classification by age, composition analysis, consequences of mismanagement, and the important role of SDGs in achieving sustainable landfill leachate management. The aim is to provide a perspective on the various aspects of landfill leachate, covering its origin, key features, global distribution, environmental impacts from poor management, and importance of SDGs which can guide for sustainable mitigation within a concise framework.

Contamination of aquatic ecosystems by persistent organic pollutants (POPs) originating from landfills in Canada and the United States: A rapid scoping review

Persistent organic pollutants (POPs) are organic chemical substances that threaten human health and the planet's ecosystems due to their toxicity and their ability to remain intact for a long time, wide distribution throughout the environment, and accumulation and magnification in living organisms through the food chain. Discarded products from landfills and dumpsites are potential sources of POPs due to their persistence for several decades and constant release to surrounding environment. POPs in aquatic systems signal input predominantly from landfills, wastewater treatment plants, sewage, and urban runoff, suggesting a research gap to guide policies to address these unabated releases. This scoping review aims to rapidly identify the key concepts underpinning the containment, translation, and migration of POPs in Canadian and US landfill leachate. The review targeted multidisciplinary perspectives on the topic and spanned forensic biology, environmental sciences, chemistry, and geology. Contaminated municipal solid waste (MSW) landfill characteristics, as reported by government agencies in Canada and the US, were synthesized and harmonized to illustrate the geographical scope of MSW landfills releasing POPs into the surrounding environment. The knowledge and data gaps summarized in this study highlight the need to address the inadvertent release of POPs from Canadian and US landfills, particularly in consideration of dated and degrading landfill infrastructure, the proximity of marginalized people, and the implications of climate change on the countries' more vulnerable landscapes. This review is applicable to the development of future studies that aim to guide environmental protective policies.

Predictive statistical models for monitoring antimicrobial resistance spread in the environment using Apis mellifera (L. 1758) colonies

The rise of antimicrobial resistance (AMR) is one of the most relevant problems for human and animal health. According to One Health Approach, it is important to regulate the use of antimicrobials and monitor the spread of AMR in the environment as well. Apis mellifera (L. 1758) colonies were used as bioindicators thanks to their physical and behavioural characteristics. During their foraging flights, bees can intercept small particles, including atmospheric particulate matter, etc., and also microorganisms. To date, the antimicrobial surveillance network is limited to the sanitary level but lacks into environmental context. This study aimed to evaluate the use of A. mellifera colonies distributed throughout the Emilia-Romagna region (Italy) as indicators of environmental antimicrobial-resistant bacteria. This was performed by creating a statistical predictive model that establishes correlations between environmental characteristics and the likelihood of isolating specific bacterial genera and antimicrobial-resistant strains. A total of 608 strains were isolated and tested for susceptibility to 19 different antimicrobials. Aztreonam-resistant strains were significantly related to environments with sanitary structures, agricultural areas and wetlands, while urban areas present a higher probability of trimethoprim/sulfamethoxazole-resistant strains isolation. Concerning genera, environments with sanitary structures and wetlands are significantly related to the genera Proteus spp., while the Escherichia spp. strains can be probably isolated in industrial environments. The obtained models showed maximum values of Models Accuracy and robustness (R2) of 55 % and 24 %, respectively. The results indicate the efficacy of utilizing A. mellifera colonies as valuable bioindicators for estimating the prevalence of AMR in environmentally disseminated bacteria. This survey can be considered a good basis for the development of further studies focused on monitoring both sanitary and animal pathology, creating a specific network in the environments of interest.

Heavy Metals as Catalysts in the Evolution of Antimicrobial Resistance and the Mechanisms Underpinning Co-selection

The menace caused by antibiotic resistance in bacteria is acknowledged on a global scale. Concerns over the same are increasing because of the selection pressure exerted by a huge number of different antimicrobial agents, including heavy metals. Heavy metals are non-metabolizable and recalcitrant to degradation, therefore the bacteria can expel the pollutants out of the system and make it less harmful via different mechanisms. The selection of antibiotic-resistant bacteria may be influenced by heavy metals present in environmental reservoirs. Through co-resistance and cross-resistance processes, the presence of heavy metals in the environment can act as co-selecting agents, hence increasing resistance to both heavy metals and antibiotics. The horizontal gene transfer or mutation assists in the selection of mutant bacteria resistant to the polluted environment. Hence, bioremediation and biodegradation are sustainable methods for the natural clean-up of pollutants. This review sheds light on the occurrence of metal and antibiotic resistance in the environment via the co-resistance and cross-resistance mechanisms underpinning co-selection emphasizing the dearth of studies that specifically examine the method of co-selection in clinical settings. Furthermore, it is advised that future research incorporate both culture- and molecular-based methodologies to further our comprehension of the mechanisms underlying bacterial co- and cross-resistance to antibiotics and heavy metals.

Airborne antibiotic and metal resistance genes - A neglected potential risk at e-waste recycling facilities

Heavy metal-rich environments can promote the selection of metal-resistance genes (MRGs) in bacteria, often leading to the simultaneous selection of antibiotic-resistance genes (ARGs) through a process known as co-selection. To comprehensively evaluate the biological pollutants at electronic-waste (e-waste) recycling facilities, air, soil, and river samples were collected at four distinct Swiss e-waste recycling facilities and analyzed for ARGs, MRGs, mobile genetic elements (MGEs), endotoxins, and bacterial species, with correlations drawn to heavy metal occurrence. To our knowledge, the present work marks the first attempt to quantify these bio-pollutants in the air of e-waste recycling facilities, that might pose a significant health risk to workers. Although ARG and MRG's profiles varied among the different sample types, intl1 consistently exhibited high relative abundance rates, identifying it as the predominant MGE across all sample types and facilities. These findings underscore its pivol role in driving diverse bacterial adaptations to extreme heavy metal exposure by selection and dissemination of ARGs and MRGs. All air samples exhibited consistent profiles of ARGs and MRGs, with blaTEM emerging as the predominant ARG, alongside pbrT and nccA as the most prevalent MRGs. However, one facility, engaged in batteries recycling and characterized by exceptionally high concentrations of heavy metals, showcased a more diverse resistance gene profile, suggesting that bacteria in this environment required more complex resistance mechanisms to cope with extreme metal exposure. Furthermore, this study unveiled a strong association between gram-negative bacteria and ARGs and less with MRGs. Overall, this research emphasizes the critical importance of studying biological pollutants in the air of e-waste recycling facilities to inform robust safety measures and mitigate the risk of resistance gene dissemination among workers. These findings establish a solid foundation for further investigations into the complex interplay among heavy metal exposure, bacterial adaptation, and resistance patterns in such distinctive ecosystems.

Scolopax rusticola Carrying Enterobacterales Harboring Antibiotic Resistance Genes

The Eurasian woodcock (Scolopax rusticola) belongs to those bird species that make systematic migratory flights in spring and autumn in search of favorable breeding and wintering areas. These specimens arrive in the Mediterranean Area from northeastern European countries during the autumn season. The purpose of this study was to assess whether woodcocks can carry antibiotic resistance genes (ARGs) along their migratory routes. Although the role of migratory birds in the spread of some zoonotic diseases (of viral and bacterial etiology) has been elucidated, the role of these animals in the spread of antibiotic resistance has not yet been clarified. In this study, we analyzed the presence of beta-lactam antibiotic resistance genes. The study was conducted on 69 strains from 60 cloacal swabs belonging to an equal number of animals shot during the 2022-2023 hunting season in Sicily, Italy. An antibiogram was performed on all strains using the microdilution method (MIC) and beta-lactam resistance genes were investigated. The strains tested showed no phenotypic resistance to any of the 13 antibiotics tested; however, four isolates of Enterobacter cloacae and three of Klebsiella oxytoca were found to carry the blaIMP-70, blaVIM-35, blaNDM-5 and blaOXA-1 genes. Our results confirm the importance of monitoring antimicrobial resistance among migratory animals capable of long-distance bacteria spread.

A review of organophosphonates, their natural and anthropogenic sources, environmental fate and impact on microbial greenhouse gases emissions - Identifying knowledge gaps

Organophosphonates (OPs) are a unique group of natural and synthetic compounds, characterised by the presence of a stable, hard-to-cleave bond between the carbon and phosphorus atoms. OPs exhibit high resistance to abiotic degradation, excellent chelating properties and high biological activity. Despite the huge and increasing scale of OP production and use worldwide, little is known about their transportation and fate in the environment. Available data are dominated by information concerning the most recognised organophosphonate - the herbicide glyphosate - while other OPs have received little attention. In this paper, a comprehensive review of the current state of knowledge about natural and artificial OPs is presented (including glyphosate). Based on the available literature, a number of knowledge gaps have been identified that need to be filled in order to understand the environmental effects of these abundant compounds. Special attention has been given to GHG-related processes, with a particular focus on CH4. This stems from the recent discovery of OP-dependent CH4 production in aqueous environments under aerobic conditions. The process has changed the perception of the biogeochemical cycle of CH4, since it was previously thought that biological methane formation was only possible under anaerobic conditions. However, there is a lack of knowledge on whether OP-associated methane is also formed in soils. Moreover, it remains unclear whether anthropogenic OPs affect the CH4 cycle, a concern of significant importance in the context of the increasing rate of global warming. The literature examined in this review also calls for additional research into the date of OPs in waste and sewage and in their impact on environmental microbiomes.

Environmental pitfalls and associated human health risks and ecological impacts from landfill leachate contaminants: Current evidence, recommended interventions and future directions

The improper management of solid waste, particularly the dumping of untreated municipal solid waste, poses a growing global challenge in both developed and developing nations. The generation of leachate is one of the significant issues that arise from this practice, and it can have harmful impacts on both the environment and public health. This paper presents an overview of the primary waste types that generate landfill leachate and their characteristics. This includes examining the distribution of waste types in landfills globally and how they have changed over time, which can provide valuable insights into potential pollutants in a given area and their trends. With a lack of specific regulations and growing concerns regarding environmental and health impacts, the paper also focuses on emerging contaminants. Furthermore, the environmental and ecological impacts of leachate, along with associated health risks, are analyzed. The potential applications of landfill leachate, suggested interventions and future directions are also discussed in the manuscript. Finally, this work addresses future research directions in landfill leachate studies, with attention, for the first time to the potentialities that artificial intelligence can offer for landfill leachate management, studies, and applications.

Advances in identifying and managing emerging contaminants in aquatic ecosystems: Analytical approaches, toxicity assessment, transformation pathways, environmental fate, and remediation strategies

Emerging contaminants (ECs) are increasingly recognized as threats to human health and ecosystems. This review evaluates advanced analytical methods, particularly mass spectrometry, for detecting ECs and understanding their toxicity, transformation pathways, and environmental distribution. Our findings underscore the reliability of current techniques and the potential of upcoming methods. The adverse effects of ECs on aquatic life necessitate both in vitro and in vivo toxicity assessments. Evaluating the distribution and degradation of ECs reveals that they undergo physical, chemical, and biological transformations. Remediation strategies such as advanced oxidation, adsorption, and membrane bioreactors effectively treat EC-contaminated waters, with combinations of these techniques showing the highest efficacy. To minimize the impact of ECs, a proactive approach involving monitoring, regulations, and public education is vital. Future research should prioritize the refining of detection methods and formulation of robust policies for EC management.

Systematic analysis of the scientific-technological production on the use of the UV, H2O2, and/or Cl2 systems in the elimination of bacteria and associated antibiotic resistance genes

This study presents a systematic review of the scientific and technological production related to the use of systems based on UV, H2O2, and Cl2 for the elimination of antibiotic-resistant bacteria (ARB) and genes associated with antibiotic resistance (ARGs). Using the Pro Know-C (Knowledge Development Process-Constructivist) methodology, a portfolio was created and analyzed that includes 19 articles and 18 patents published between 2011 and 2022. The results show a greater scientific-technological production in UV irradiation systems (8 articles and 5 patents) and the binary combination UV/H2O2 (9 articles and 4 patents). It was emphasized that UV irradiation alone focuses mainly on the removal of ARB, while the addition of H2O2 or Cl2, either individually or in binary combinations with UV, enhances the removal of ARB and ARG. The need for further research on the UV/H2O2/Cl2 system is emphasized, as gaps in the scientific-technological production of this system (0 articles and 2 patents), especially in its electrochemically assisted implementation, have been identified. Despite the gaps identified, there are promising prospects for the use of combined electrochemically assisted UV/H2O2/Cl2 disinfection systems. This is demonstrated by the effective removal of a wide range of contaminants, including ARB, fungi, and viruses, as well as microorganisms resistant to conventional disinfectants, while reducing the formation of toxic by-products.

Resistomes in freshwater bioaerosols and their impact on drinking and recreational water safety: A perspective

Antibiotic resistance genes (ARGs) are widespread environmental pollutants of biological origin that pose a significant threat to human, animal, and plant health, as well as to ecosystems. ARGs are found in soil, water, air, and waste, and several pathways for global dissemination in the environment have been described. However, studies on airborne ARG transport through atmospheric particles are limited. The ARGs in microorganisms inhabiting an environment are referred to as the "resistome". A global search was conducted of air-resistome studies by retrieving bioaerosol ARG-related papers published in the last 30 years from PubMed. We found that there is no dedicated methodology for isolating ARGs in bioaerosols; instead, conventional methods for microbial culture and metagenomic analysis are used in combination with standard aerosol sampling techniques. There is a dearth of information on the bioaerosol resistomes of freshwater environments and their impact on freshwater sources used for drinking and recreational activities. More studies of aerobiome freshwater environments are needed to ensure the safe use of water and sanitation. In this review we outline and synthesize the few studies that address the freshwater air microbiome (from tap water, bathroom showers, rivers, lakes, and swimming pools) and their resistomes, as well as the likely impacts on drinking and recreational waters. We also discuss current knowledge gaps for the freshwater airborne resistome. This review will stimulate new investigations of the atmospheric microbiome, particularly in areas where both air and water quality are of public health concern.

Exogenous mobile genetic elements and their associated integrons drive the enrichment of antibiotic-resistant genes in the river of a valley basin city (Lanzhou, China)

River is a unique source of drinking water in valley-type cities, affecting local urban development and human lifestyles. However, the key driving factors for dissemination of antibiotic-resistant genes (ARGs) in valley-type urban environments remain unclear. This study aimed to investigate the distribution of ARGs in the Yellow River and to clarify the driving factors of ARGs in a typical valley basin city (Lanzhou, China). The seven selected ARGs with higher abundances including tetracycline resistance genes (tetM, tetX), macrolide resistance genes (ermB, ermF, ereA), and sulfonamide resistance genes (sul1, sul2) were detected. The results showed that the total absolute abundance of all the selected ARGs varied from 9.97 × 1012 to 1.04 × 1015 copies/L in the water body, with higher abundances in the wet season, relative to the dry season. Among these, sulfonamide resistance genes (sul1, sul2) displayed the highest absolute abundance in the river and soil. The ARGs and mobile genetic elements (MGEs) were significantly correlated with bacterial abundance, dissolved organic carbon (DOC), ammonia nitrogen (NH4+), and total nitrogen (TN) levels in the water environment (Mantel test, P < 0.01). Structural equation modeling revealed the direct input of point-source and nonpoint-source ARGs in this area contributed less to the overall level of the ARGs in the water. Among the multiple drivers, the MGEs derived from wastewater treatment plant and anthropogenic nonpoint area positively and directly affected the ARG profiles in water (P < 0.01), rather than the factors of bacterial abundance and physicochemical properties. According to this study, the exogenous MGEs from anthropogenic activities are the main driver for the enrichment of ARGs in the valley-type urban river environment.

Snapshot of resistome, virulome and mobilome in aquaculture

Aquaculture environments can be hotspots for resistance genes through the surrounding environment. Our objective was to study the resistome, virulome and mobilome of Gram-negative bacteria isolated in seabream and bivalve molluscs, using a WGS approach. Sixty-six Gram-negative strains (Aeromonadaceae, Enterobacteriaceae, Hafniaceae, Morganellaceae, Pseudomonadaceae, Shewanellaceae, Vibrionaceae, and Yersiniaceae families) were selected for genomic characterization. The species and MLST were determined, and antibiotic/disinfectants/heavy metals resistance genes, virulence determinants, MGE, and pathogenicity to humans were investigated. Our study revealed new sequence-types (e.g. Aeromonas spp. ST879, ST880, ST881, ST882, ST883, ST887, ST888; Shewanella spp. ST40, ST57, ST58, ST60, ST61, ST62; Vibrio spp. ST206, ST205). >140 different genes were identified in the resistome of seabream and bivalve molluscs, encompassing genes associated with β-lactams, tetracyclines, aminoglycosides, quinolones, sulfonamides, trimethoprim, phenicols, macrolides and fosfomycin resistance. Disinfectant resistance genes qacE-type, sitABCD-type and formA-type were found. Heavy metals resistance genes mdt, acr and sil stood out as the most frequent. Most resistance genes were associated with antibiotics/disinfectants/heavy metals commonly used in aquaculture settings. We also identified 25 different genes related with increased virulence, namely associated with adherence, colonization, toxins production, red blood cell lysis, iron metabolism, escape from the immune system of the host. Furthermore, 74.2 % of the strains analysed were considered pathogenic to humans. We investigated the genetic environment of several antibiotic resistance genes, including blaTEM-1B, blaFOX-18, aph(3″)-Ib, dfrA-type, aadA1, catA1-type, tet(A)/(E), qnrB19 and sul1/2. Our analysis also focused on identifying MGE in proximity to these genes (e.g. IntI1, plasmids and TnAs), which could potentially facilitate the spread of resistance among bacteria across different environments. This study provides a comprehensive examination of the diversity of resistance genes that can be transferred to both humans and the environment, with the recognition that aquaculture and the broader environment play crucial roles as intermediaries within this complex transmission network.

Zinc/carbon nanomaterials inhibit antibiotic resistance genes by affecting quorum sensing and microbial community in cattle manure production

This study used metagenomic sequencing to examine the effects of carbon-based zinc oxide nanoparticles (CZnONPs) and graphene-based zinc oxide nanoparticles (GZnONPs) on quorum sensing (QS), antibiotic resistance genes (ARGs) and microbial community changes during cattle manure production. The manure zinc content was significantly reduced in GZnONPs group. In the QS pathway, the autoinducer gene increases significantly in Control group, while the transporter and repressor genes experience a substantial increase in CZnONPs group. These results contributed to the significantly decreased the abundance of ARGs in GZnONPs group. The co-occurrence network analysis revealed a correlation between core ARGs and QS-related KEGG Orthology or ARGs' hosts, indicating that the selective pressure of zinc influences microbial QS, forming a unique ARG pattern in in vivo anaerobic fermentation. These findings suggest that implementing nutritional regulation in farming practices can serve as a preventive measure to mitigate the potential transmission of ARGs resulting from livestock waste.

Staphylococcus aureus Carriage in the Nasotracheal Cavities of White Stork Nestlings (Ciconia ciconia) in Spain: Genetic Diversity, Resistomes and Virulence Factors

The molecular ecology of Staphylococcus aureus in migratory birds (such as white storks) is necessary to understand their relevance in the "One Health" ecosystems. This study determined the nasotracheal carriage rates of S. aureus from white storks in Southern Spain and genetically characterized the within-host diversity. A collection of 67 S. aureus strains, previously obtained from 87 white stork nestlings (52 nasal and 85 tracheal samples) fed by their parents with food foraged in natural and landfill habitats, were tested for their antimicrobial resistance (AMR) phenotypes. Moreover, the AMR genotypes, immune evasion cluster (IEC), virulence genes and the detection of CC398 lineage were studied by PCR. The spa types and multilocus-sequencing-typing (MLST) were also determined by PCR and sequencing. Staphylococcus aureus carriage was found in 31% of storks (36.5%/11.9% in nasal/tracheal samples). All isolates were methicillin-susceptible (MSSA) and 8.8% of them were also susceptible to all tested antibiotics. The AMR phenotype/percentage/genes detected were as follows: penicillin/79.1%/blaZ; erythromycin-clindamycin-inducible/19.1%/ermA, ermT; tetracycline/11.9%/tetK; clindamycin/4.5%/lnuA and ciprofloxacin/4.5%. Twenty-one different spa types, including 2 new ones (t7778-ST15-CC15 and t18009-ST26-CC25), were detected and ascribed to 11 clonal complexes (CCs). MSSA-CC398 (8.2%), MSSA-CC15 (7.1%) and MSSA-ST291 (5.9%) were the most prevalent lineages in storks. Moreover, tst-positive (MSSA-CC22-t223 and MSSA-CC30-t1654), eta-positive (MSSA-CC9-t209) and etb-positive strains (MSSA-CC45-t015) were detected in four storks. The 18.5% of storks harboured distinct MSSA strains (with different lineages and/or AMR genes). Nestlings of storks foraging in landfills (10 CCs) had more diverse S. aureus strains than those of parents foraging in natural habitats (3 CCs). Low level of AMR was demonstrated among S. aureus strains. The predominance of MSSA-CC398 (an emergent clade) and toxigenic MSSA strains in stork nestlings highlight the need for continuous surveillance of S. aureus in wild birds.

Current Scenario and Future Prospects of Endophytic Microbes: Promising Candidates for Abiotic and Biotic Stress Management for Agricultural and Environmental Sustainability

Globally, substantial research into endophytic microbes is being conducted to increase agricultural and environmental sustainability. Endophytic microbes such as bacteria, actinomycetes, and fungi inhabit ubiquitously within the tissues of all plant species without causing any harm or disease. Endophytes form symbiotic relationships with diverse plant species and can regulate numerous host functions, including resistance to abiotic and biotic stresses, growth and development, and stimulating immune systems. Moreover, plant endophytes play a dominant role in nutrient cycling, biodegradation, and bioremediation, and are widely used in many industries. Endophytes have a stronger predisposition for enhancing mineral and metal solubility by cells through the secretion of organic acids with low molecular weight and metal-specific ligands (such as siderophores) that alter soil pH and boost binding activity. Finally, endophytes synthesize various bioactive compounds with high competence that are promising candidates for new drugs, antibiotics, and medicines. Bioprospecting of endophytic novel secondary metabolites has given momentum to sustainable agriculture for combating environmental stresses. Biotechnological interventions with the aid of endophytes played a pivotal role in crop improvement to mitigate biotic and abiotic stress conditions like drought, salinity, xenobiotic compounds, and heavy metals. Identification of putative genes from endophytes conferring resistance and tolerance to crop diseases, apart from those involved in the accumulation and degradation of contaminants, could open new avenues in agricultural research and development. Furthermore, a detailed molecular and biochemical understanding of endophyte entry and colonization strategy in the host would better help in manipulating crop productivity under changing climatic conditions. Therefore, the present review highlights current research trends based on the SCOPUS database, potential biotechnological interventions of endophytic microorganisms in combating environmental stresses influencing crop productivity, future opportunities of endophytes in improving plant stress tolerance, and their contribution to sustainable remediation of hazardous environmental contaminants.

Investigating the Antagonistic Effect of Indigenous Probiotics on Carbapenem-Resistant Pseudomonas aeruginosa Strains

Introduction

With the increase of hospital infections due to the indiscriminate use of antibiotics, multidrug resistance has increased, decreasing the effectiveness of antibiotics against these infections. For this reason, the identification of alternative agents such as probiotics has been considered. The aim of this study was to isolate and identify effective probiotics against carbapenem-resistant Pseudomonas aeruginosa strains. Material and Methods. During a period of eight months, isolates of P. aeruginosa were collected from patients in three hospitals in Isfahan. The presence of metallo-beta-lactamase enzymes was determined by the combination disc test (CDT). The inhibitory and antimicrobial activities of 20 probiotic bacteria isolated from local dairy products against these strains were investigated by agar dilution. Two probiotic strains that showed broader inhibition results were selected, and the values of the lowest inhibitory concentration (MIC) and the lowest lethal concentration (MBC) and their antibiofilm effect were determined using the microtiter plate method. The concentration of organic acids was done by HPLC. Findings. Of the 100 samples isolated and identified, 61 samples (61%) exhibited multiple drug resistance (MDR) and were selected for further investigation. Phenotypic diagnosis of the presence of metallo-beta-lactamase enzymes revealed that 74.5% of the strains were positive. The results showed that these two probiotics killed P. aeruginosa strains after only one hour, and the inhibition mechanism was due to the presence of lactic acid and acetic acid. The antibiofilm effect of these two probiotics was at concentrations of 1/2 and 1/4.

Conclusion

The two Lactobacillus isolates had potential antimicrobial and antibiofilm properties against all carbapenem-resistant P. aeruginosa strains, even at thinner dilutions. Considering the broad activity of this strain, it can potentially be used for biocontrol of these strains.

An overview on the prevalence and potential impact of antimicrobials and antimicrobial resistance in the aquatic environment of India

India at present is one of the leading countries in antimicrobial drug production and use, leading to increasing antimicrobial resistance (AMR) and public health problems. Attention has mainly been focused on the human and food animals' contribution to AMR neglecting the potential contribution of the perceptibly degraded aquatic environment in India. The paper reviews the available published literature in India on the prevalence of antimicrobial residues and their dissemination pathways in wastewater of pharmaceutical industries, sewage treatment plants, hospitals, riverine, community pond water, and groundwater. The prevalence of antimicrobial residue concentration, pathogenic and non-pathogenic bacteria antimicrobial resistant bacteria (ARB), their drug resistance levels, and their specific antimicrobial resistant genes (ARGs) occurring in various water matrices of India have been comprehensively depicted from existing literature. The concentration of some widely used antimicrobials recorded from the sewage treatment plants and hospital wastewater and rivers in India has been compared with other countries. The ecotoxicological risk posed by these antimicrobials in the various water matrices in India indicated high hazard quotient (HQ) values for pharmaceutical effluents, hospital effluents, and river water. The degraded aquatic environment exhibited the selection of a wide array of co-existent resistant genes for antibiotics and metals. The review revealed improper use of antibiotics and inadequate wastewater treatment as major drivers of AMR contaminating water bodies in India and suggestion for containing the challenges posed by AMR in India has been proposed.

Mechanism of antibiotic resistance development in an activated sludge system under tetracycline pressure

The mechanism of antibiotic resistance (AR) development in an activated sludge system under tetracycline (TC) pressure was discussed and analyzed. According to the variation of macro-factors, including TC, COD, TN, TP, NH3-N, pH, heavy metals, and reactor settings, the tet genes respond accordingly. Consequently, the enrichment sites of tet genes form an invisible AR selection zone, where AR microorganisms thrive, gather, reproduce, and spread. The efflux pump genes tetA and tetB prefer anaerobic environment, while ribosome protective protein genes tetM, tetO, tetQ, tetT, and tetW were more concentrated in aerobic situations. As a corresponding micro-effect, different types of tet genes selected the corresponding dominant bacteria such as Thauera and Arthrobacter, suggesting the intrinsic relationship between tet genes and potential hosts. In summary, the macro-response and micro-effect of tet genes constitute an interactive mechanism with tet genes as the core, which is the crucial cause for the continuous development of AR. This study provides an executable strategy to control the development of AR in actual wastewater treatment plants from the perspective of macro-factors and micro-effects.

Human health risks of metal contamination in Shallow Wells around waste dumpsites in Abeokuta Metropolis, Southwestern, Nigeria

Metal contamination in shallow wells through solid waste leaching is a serious environmental problem with contribution to global cancer cases. This paper evaluated the health risks of metals in shallow wells around dumpsites in the Abeokuta metropolis, Nigeria. Five dumpsites were purposively selected to sample twenty-five shallow wells. In situ and laboratory analyses for physico-chemical parameters, copper, lead, cadmium, iron, and chromium were conducted following the APHA standard procedure. Carcinogenic and non-carcinogenic risks for oral and dermal routes were evaluated for adult males and females, children, and infants. Findings revealed that all wells were acidic (pH = 5.82-6.48), with Fe and Cd concentrations above the established limits. The wells around Obada, Obantoko, and Saje dumpsites had high EC (up to 1200 µS/cm), Cu, and Pb concentrations above the permissible limits. Non-carcinogenic risks for oral ingestion were significant for all age groups (hazard index: HI > 1), and the significance level across dumping areas increased in the order: Saje > Obantoko > Obada > Idi-aba > Lafenwa. All wells assessed in Saje and Obantoko recorded significant HI of dermal exposure for children and infants. Cancer risks were significant for all age groups (CR > 1.0E - 04), and metal contributions followed: Cd > Cr > Pb. The overall trend of significant risks for non-carcinogenic and carcinogenic via oral and dermal routes is in the order of infant > children > adult female > adult male. This suggests that groundwater users within the studied areas may experience diverse illnesses or cancer in their lifetime, particularly children and infants.

Performance of a Pilot-Scale Continuous Flow Ozone-Based Hospital Wastewater Treatment System

Antimicrobial resistance (AMR) is becoming a global concern. Recently, research has emerged to evaluate the human and environmental health implications of wastewater from medical facilities and to identify acceptable wastewater treatment methods. In this study, a disinfection wastewater treatment system using an ozone-based continuous flow system was installed in a general hospital located in Japan. The effectiveness of antimicrobial-resistant bacteria (ARB) and antimicrobials in mitigating the environmental impact of hospital wastewater was evaluated. Metagenomic analysis was conducted to characterize the microorganisms in the wastewater before and after treatment. The results demonstrated that ozone treatment enables effective inactivation of general gut bacteria, including Bacteroides, Prevotella, Escherichia coli, Klebsiella, DNA molecules, and ARGs, as well as antimicrobials. Azithromycin and doxycycline removal rates were >99% immediately after treatment, and levofloxacin and vancomycin removal rates remained between 90% and 97% for approximately one month. Clarithromycin was more readily removed than the other antimicrobials (81-91%), and no clear removal trend was observed for ampicillin. Our findings provide a better understanding of the environmental management of hospital wastewater and enhance the effectiveness of disinfection wastewater treatment systems at medical facilities for mitigating the discharge of pollutants into aquatic environments.

Microplastics and Antibiotic Resistance: The Magnitude of the Problem and the Emerging Role of Hospital Wastewater

The role of microplastics (MPs) in the spread of antibiotic resistance genes (ARGs) is increasingly attracting global research attention due to their unique ecological and environmental effects. The ubiquitous use of plastics and their release into the environment by anthropic/industrial activities are the main sources for MP contamination, especially of water bodies. Because of their physical and chemical characteristics, MPs represent an ideal substrate for microbial colonization and formation of biofilm, where horizontal gene transfer is facilitated. In addition, the widespread and often injudicious use of antibiotics in various human activities leads to their release into the environment, mainly through wastewater. For these reasons, wastewater treatment plants, in particular hospital plants, are considered hotspots for the selection of ARGs and their diffusion in the environment. As a result, the interaction of MPs with drug-resistant bacteria and ARGs make them vectors for the transport and spread of ARGs and harmful microorganisms. Microplastic-associated antimicrobial resistance is an emerging threat to the environment and consequently for human health. More studies are required to better understand the interaction of these pollutants with the environment as well as to identify effective management systems to reduce the related risk.

Metal- and antibiotic-resistant heterotrophic plate count bacteria from a gold mine impacted river: the Mooi River system, South Africa

The Wonderfonteinspruit, South Africa, is highly impacted by a century of gold mining activities. The aim of this study was to investigate the physico-chemical properties of the Wonderfonteinspruit and the receiving Mooi River system, the levels of antimicrobial (metals and antibiotics) resistance characteristics and heterotrophic bacteria levels in these water systems. Various physico-chemical parameters were determined. R2A agar and R2A agar supplemented with antimicrobials were used to enumerate heterotrophic bacteria. Morphologically distinct antimicrobial-resistant isolates were purified and screened for antibiotic susceptibility by a disc diffusion method. Selected isolates were identified, and minimum inhibitory concentration ranges determined. Among the antimicrobial resistant isolates, 87% were resistant to at least one antibiotic. Of these, almost 50% were resistant to more than 3 antibiotic classes. A large proportion was resistant to all 7 antibiotics tested. Phyla detected were Proteobacteria, Firmicutes and Bacteriodetes. High MIC levels for metals and antibiotics were detected among all the genera. Results demonstrate potential impacts of physico-chemical properties on levels of antimicrobial-resistant bacteria. Metal-resistant bacteria were also resistant to multiple antibiotics, suggesting that metal pollution from mining may be responsible for co-selection and maintenance of antibiotic-resistant bacteria in this aquatic system.

Evaluation of pre-treated healthcare wastes during COVID-19 pandemic reveals pathogenic microbiota, antibiotics residues, and antibiotic resistance genes against beta-lactams

The disposal of healthcare waste without prior elimination of pathogens and hazardous contaminants has negative effects on the environment and public health. This study aimed to profile the complete microbial community and correlate it with the antibiotic compounds identified in microwave pre-treated healthcare wastes collected from three different waste operators in Peninsular Malaysia. The bacterial and fungal compositions were determined via amplicon sequencing by targeting the full-length 16S rRNA gene and partial 18S with full-length ITS1-ITS2 regions, respectively. The antibiotic compounds were characterized using high-throughput spectrometry. There was significant variation in bacterial and fungal composition in three groups of samples, with alpha- (p-value = 0.04) and beta-diversity (p-values <0.006 and < 0.002), respectively. FC samples were found to acquire more pathogenic microorganisms than FA and FV samples. Paenibacillus and unclassified Bacilli genera were shared among three groups of samples, meanwhile, antibiotic-resistant bacteria Proteus mirabilis, Enterococcus faecium, and Enterococcus faecalis were found in modest quantities. A total of 19 antibiotic compounds were discovered and linked with the microbial abundance detected in the healthcare waste samples. The principal component analysis demonstrated a positive antibiotic-bacteria correlation for genera Pseudomonas, Aerococcus, Comamonas, and Vagococcus, while the other bacteria were negatively linked with antibiotics. Nevertheless, deep bioinformatic analysis confirmed the presence of blaTEM-1 and penP which are associated with the production of class A beta-lactamase and beta-lactam resistance pathways. Microorganisms and contaminants, which serve as putative indicators in healthcare waste treatment evaluation revealed the ineffectiveness of microbial inactivation using the microwave sterilization method. Our findings suggested that the occurrence of clinically relevant microorganisms, antibiotic contaminants, and associated antibiotic resistance genes (ARGs) represent environmental and human health hazards when released into landfills via ARGs transmission.

Occurrence, fate, and risk assessment of antibiotics in typical pharmaceutical manufactories and receiving water bodies from different regions

This study aimed to investigate the presence and persistence of antibiotics in wastewater of four typical pharmaceutical manufactories in China and receiving water bodies and suggest the removal of antibiotics by the wastewater treatment process. It also evaluated the environmental impact of antibiotic residues through wastewater discharge into receiving water bodies. The results indicated that thirteen antibiotics were detected in wastewater samples with concentrations ranging from 57.03 to 726.79 ng/L. Fluoroquinolones and macrolides were the most abundant antibiotic classes found in wastewater samples, accounting for 42.5% and 38.7% of total antibiotic concentrations, respectively, followed by sulfonamides (16.4%) and tetracyclines (2.4%). Erythromycin-H2O, lincomycin, ofloxacin, and trimethoprim were the most frequently detected antibiotics; among these antibiotics, the concentration of ofloxacin was the highest in most wastewater samples. No significant difference was found in different treatment processes used to remove antibiotics in wastewater samples. More than 50% of antibiotics were not completely removed with a removal efficiency of less than 70%. The concentration of detected antibiotics in the receiving water bodies was an order of magnitude lower than that in the wastewater sample due to dilution. An environmental risk assessment showed that lincomycin and ofloxacin could pose a high risk at the concentrations detected in effluents and a medium risk in their receiving water bodies, highlighting a potential hazard to the health of the aquatic ecosystem. Overall, The investigation was aimed to determine and monitor the concentration of selected antibiotics in 4 typical PMFs and their receiving water bodies, and to study the removal of these substances in PMFs. This study will provide significant data and findings for future studies on antibiotics-related pollution control and management in water bodies.

Development of a GIS-based knowledge hub for contaminants of emerging concern in South African water resources using open-source software: Lessons learnt

With population growth and dwindling freshwater sources, protecting such sources has come to the forefront of water resource management. Historically, society's response to a problem is based on funding availability, current threat, and public outcry. Achieving this is largely dependent on the knowledge of the factors that are resulting in compromised water sources. These factors are constantly changing as novel contaminants are introduced into surface water sources. As we are in the information age, the interest in contaminants of emerging concern (CEC) is gaining ground. Whilst research is being conducted to identify contaminants in South African water sources, the research outputs and available information is not collated and presented to the science community and stakeholders in readily available formats and platforms. Current research outcomes need to be made known to regulators in order to develop environmental laws. By using fourth industrial revolution technology, we were able to collate available data in literature and display these in a user-friendly online format to regulatory bodies as well as researchers. A standardized excel spreadsheet was developed and uploaded to a PostgreSQL, running a PostGIS extension and was then processed in the GeoServer to allow for visualization on an interactive map which can be continuously updated. The near real-time access to information will reduce the possibility of duplication of research efforts, enhance collaboration in the discipline, and act as a CEC early warning system.

Microbial strategies for degradation of microplastics generated from COVID-19 healthcare waste

COVID-19 pandemic has led to the generation of massive plastic wastes, comprising of onetime useable gloves, masks, tissues, and other personal protective equipment (PPE). Recommendations for the employ of single-use disposable masks made up of various polymeric materials like polyethylene, polyurethane, polyacrylonitrile, and polypropylene, polystyrene, can have significant aftermath on environmental, human as well as animal health. Improper disposal and handling of healthcare wastes and lack of proper management practices are creating serious health hazards and an extra challenge for the local authorities designated for management of solid waste. Most of the COVID-19 medical wastes generated are now being treated by incineration which generates microplastic particles (MPs), dioxin, furans, and various toxic metals, such as cadmium and lead. Moreover, natural degradation and mechanical abrasion of these wastes can lead to the generation of MPs which cause a serious health risk to living beings. It is a major threat to aquatic lives and gets into foods subsequently jeopardizing global food safety. Moreover, the presence of plastic is also considered a threat owing to the increased carbon emission and poses a profound danger to the global food chain. Degradation of MPs by axenic and mixed culture microorganisms, such as bacteria, fungi, microalgae etc. can be considered an eco-sustainable technique for the mitigation of the microplastic menace. This review primarily deals with the increase in microplastic pollution due to increased use of PPE along with different disinfection methods using chemicals, steam, microwave, autoclave, and incineration which are presently being employed for the treatment of COVID-19 pandemic-related wastes. The biological treatment of the MPs by diverse groups of fungi and bacteria can be an alternative option for the mitigation of microplastic wastes generated from COVID-19 healthcare waste.

Antibiotic-Resistant Escherichia coli Strains Isolated from Captive Giant Pandas: A Reservoir of Antibiotic Resistance Genes and Virulence-Associated Genes

Recent studies showed that Escherichia coli (E. coli) strains isolated from captive giant pandas have serious resistance to antibiotics and carry various antibiotic resistance genes (ARGs). ARGs or virulence-associated genes (VAGs) carried by antibiotic-resistant E. coli are considered as a potential health threat to giant pandas, humans, other animals and the environment. In this study, we screened ARGs and VAGs in 84 antibiotic-resistant E. coli strains isolated from clinically healthy captive giant pandas, identified the association between ARGs and VAGs and analyzed the phylogenetic clustering of E. coli isolates. Our results showed that the most prevalent ARG in E. coli strains isolated from giant pandas is bla_TEM (100.00%, 84/84), while the most prevalent VAG is fimC (91.67%, 77/84). There was a significant positive association among 30 pairs of ARGs, of which the strongest was observed for sul1/tetC (OR, 133.33). A significant positive association was demonstrated among 14 pairs of VAGs, and the strongest was observed for fyuA/iroN (OR, 294.40). A positive association was also observed among 45 pairs of ARGs and VAGs, of which the strongest was sul1/eaeA (OR, 23.06). The association of ARGs and mobile gene elements (MGEs) was further analyzed, and the strongest was found for flor and intI1 (OR, 79.86). The result of phylogenetic clustering showed that the most prevalent group was group B2 (67.86%, 57/84), followed by group A (16.67%, 14/84), group D (9.52%, 8/84) and group B1 (5.95%, 5/84). This study implied that antibiotic-resistant E. coli isolated from captive giant pandas is a reservoir of ARGs and VAGs, and significant associations exist among ARGs, VAGs and MGEs. Monitoring ARGs, VAGs and MGEs carried by E. coli from giant pandas is beneficial for controlling the development of antimicrobial resistance.

Chemicals/materials of emerging concern in farmlands: sources, crop uptake and potential human health risks

Certain chemicals/materials that are contaminants of emerging concern (CECs) have been widely detected in water bodies and terrestrial systems worldwide while other CECs occur at undetectable concentrations. The primary sources of CECs in farmlands are agricultural inputs, such as wastewater, biosolids, sewage sludge, and agricultural mulching films. The percent increase in cropland area during 1950-2016 was 30 and the rise in land use for food crops during 1960-2018 was 100-500%, implying that there could be a significant CEC burden in farmlands in the future. In fact, the alarming concentrations (μg kg^-1) of certain CECs such as PBDEs, PAEs, and PFOS that occur in farmlands are 383, 35 400 and 483, respectively. Also, metal nanoparticles are reported even at the mg kg^-1 level. Chronic root accumulation followed by translocation of CECs into plants results in their detectable concentrations in the final plant produce. Thus, there is a continuous flow of CECs from farmlands to agricultural produce, causing a serious threat to the terrestrial food chain. Consequently, CECs find their way to the human body directly through CEC-laden plant produce or indirectly via the meat of grazing animals. Thus, human health could be at the most critical risk since several CECs have been shown to cause cancers, disruption of endocrine and cognitive systems, maternal-foetal transfer, neurotoxicity, and genotoxicity. Overall, this comprehensive review provides updated information on contamination of chemicals/materials of concern in farmlands globally, sources for their entry, uptake by crop plants, and their likely impact on the terrestrial food chain and human health.

Microbial community profiling in bio-stimulated municipal solid waste for effective removal of organic pollutants containing endocrine disrupting chemicals

The study was aimed to improve the degradation of organic pollutants in municipal solid waste (MSW) through the bio-stimulation process. The results showed that the physico-chemical properties of MSW (control) had a high value of pH (9.2 ± 0.02); total suspended solids (TSS: 1547 ± 23 mg/kg^-1), and total dissolved solids (TDS:76 ± 0.67 mg/kg^-1). After the biostimulation process (biostimulated MSW), the physico-chemical parameters of MSW were reduced as pH (7.1 ± 0.01); TSS (41 ± 0.01 mg/kg^-1), and TDS (789 ± 03 mg/kg^-1). Furthermore, the major organic pollutants detected from MSW by gas chromatography-mass spectroscopy (GC-MS) analysis at different retention time (RT) were hexadecane (RT-8.79); pentadecane (RT-9.36); and hexasiloxane (RT-9.43) while these organic pollutants were degraded after the biostimulation process. The whole-genome metagenome sequencing size (%) analyses showed major groups of bacteria (40.82%) followed by fungi (0.05%), virus (0.0032%), and archaea (0.0442%) in MSW. The species richness and evenness of the microbial community were decreased substantially due to the biostimulation treatment. The total number of genes in the biostimulated MSW (PS-3_11267) sample were 465302 whereas the number of genes in the control MSW (PS-4_11268) sample were 256807. Furthermore, the biostimulated MSW (PS-3_11267) aligned the reads to bacteria (19502525), fungi (40030), virus (3339), and archaea (12759) genomes whereas the control sample (PS-4_11268) aligned the reads to bacteria (17057259), fungi (19148), virus (1335), and archaea (18447) genomes. Moreover, the relative abundance at genus level in biostimulated MSW (PS-3_11267) (Ochrobactrum and Phenylobacterium), phylum; (Proteobacteria and Actinobacteria), and species (Chthoniobacter flavus and Vulgatibacter incomptus) level was the most abundant. The results provided valuable information regarding the degradation of organic pollutants in MSW by microbial communities through biostimulation for the prevention of soil pollution and health protection.

A review of some medicinal plants with the potential to defeat antimicrobial resistance: Cases of Benin, Togo, Ghana, Burkina Faso, and Cape Verde

Antimicrobial resistance (AMR) is a global public health problem. In the alternatives being explored for developing new antimicrobials, medicinal plants occupy an important place, particularly in Africa, where they are widely used. This review aims to analyze the potential of medicinal plants from Benin, Togo, Ghana, Burkina-Faso, and Cape Verde in the fight against AMR. A bibliographic search was conducted to explore scientific databases such as PubMed and Google Scholar. During this search, particular attention was given to epidemiological data related to AMR in these countries, medicinal plants traditionally used to treat microbial infections and medicinal plants that have been shown to be active on multidrug-resistant microbial strains. In total, 94 manuscripts were investigated. Epidemiological data showed that the problem of AMR is worsening in each target country. In addition, several medicinal plants have been demonstrated to be effective against microbial strains resistant to conventional antibiotics. A total of 532 medicinal plants were identified according to their ethnomedical uses for the treatment of microbial infections. Scientific evidence was collected on the antimicrobial potential of 91 plants. This study showed the potential of medicinal plants in the fight against AMR. Their documented traditional use, coupled with the evidence of efficacy provided, make them interesting sources for developing new antimicrobials.

Current advances and research prospects for agricultural and industrial uses of microbial strains available in world collections

Microorganisms are an important component of the ecosystem and have an enormous impact on human lives. Moreover, microorganisms are considered to have desirable effects on other co-existing species in a variety of habitats, such as agriculture and industries. In this way, they also have enormous environmental applications. Hence, collections of microorganisms with specific traits are a crucial step in developing new technologies to harness the microbial potential. Microbial culture collections (MCCs) are a repository for the preservation of a large variety of microbial species distributed throughout the world. In this context, culture collections (CCs) and microbial biological resource centres (mBRCs) are vital for the safeguarding and circulation of biological resources, as well as for the progress of the life sciences. Ex situ conservation of microorganisms tagged with specific traits in the collections is the crucial step in developing new technologies to harness their potential. Type strains are mainly used in taxonomic study, whereas reference strains are used for agricultural, biotechnological, pharmaceutical research and commercial work. Despite the tremendous potential in microbiological research, little effort has been made in the true sense to harness the potential of conserved microorganisms. This review highlights (1) the importance of available global microbial collections for man and (2) the use of these resources in different research and applications in agriculture, biotechnology, and industry. In addition, an extensive literature survey was carried out on preserved microorganisms from different collection centres using the Web of Science (WoS) and SCOPUS. This review also emphasizes knowledge gaps and future perspectives. Finally, this study provides a critical analysis of the current and future roles of microorganisms available in culture collections for different sustainable agricultural and industrial applications. This work highlights target-specific potential microbial strains that have multiple important metabolic and genetic traits for future research and use.

Impact of Anthropogenic Activities on the Dissemination of ARGs in the Environment-A Review

Over the past few decades, due to the excessive consumption of drugs in human and veterinary medicine, the antimicrobial resistance (AR) of microorganisms has risen considerably across the world, and this trend is predicted to intensify. Many worrying research results indicate the occurrence of pools of AR, both directly related to human activity and environmental factors. The increase of AR in the natural environment is mainly associated with the anthropogenic activity. The dissemination of AR is significantly stimulated by the operation of municipal facilities, such as wastewater treatment plants (WWTPs) or landfills, as well as biogas plants, agriculture and farming practices, including animal production and land application of manure. These activities entail a risk to public health by spreading bacteria resistant to antimicrobial products (ARB) and antibiotic resistance genes (ARGs). Furthermore, subinhibitory concentrations of antimicrobial substances additionally predispose microbial consortia and resistomes to changes in particular environments that are permeated by these micropollutants. The current state of knowledge on the fate of ARGs, their dissemination and the complexity of the AR phenomenon in relation to anthropogenic activity is inadequate. This review summarizes the state-of-the-art knowledge on AR in the environment, in particular focusing on AR spread in an anthropogenically altered environment and related environmental consequences.

Effect of pesticides on nitrification activity and its interaction with chemical fertilizer and manure in long-term paddy soils

Effect of pesticides on nitrification activity and its interaction among heavy metal concentrations (HMCs), antibiotic resistance genes (ARGs), and ammonia monooxygenase (amoA) genes of long-term paddy soils is little known. The aim was to study the effect of pesticides on net nitrification rate (NR), potential nitrification rate (NP), HMCs, ARGs (sulI, sulII, tetO, and tetQ), and amoA (amoA-AOA, amoA-AOB, and amoA-NOB) genes in long-term treated paddy soils. NR and NP were significantly decreased (p < 0.05), whereas HMCs (Pb²⁺, Cu²⁺, Zn²⁺, and Fe³⁺) were a significantly increased (p < 0.05) in chemical fertilizer with pesticide treated paddy soils as compared with chemical fertilizer treated paddy soils. The scatter plot matrix indicated that total carbon (TC), soil organic carbon (SOC), total nitrogen (TN), and Fe were linearly correlated with NR and NP in long-term treated paddy soils. ARGs and amoA genes were significantly decreased (p < 0.05) in chemical fertilizer and manure with pesticide treated paddy soils. Overall, the result indicated the response of pesticide and their combination of manure with pesticide interaction present in long-term paddy soils, which will play a great role in the control uses of pesticides, manure, and chemical fertilizers in paddy soils and protect the nitrogen cycle as well as environment.

Beta-Lactam-Resistant Enterobacterales Isolated from Landfill Leachates

Antibiotic resistance is one of the main challenges worldwide due to the high morbidity and mortality caused by infections produced by resistant bacteria. In Colombia, this problem has been studied mainly from the clinical perspective; however, it is scarcely studied in the leachates produced in landfills. The objective of this study was to detect, identify and determine the antibiotic sensitivity profile of Enterobacterales isolated from a leachate treatment plant located in Cali, Colombia. Detection was performed using selective culture media, bacterial identification using Matrix-Assisted Laser Desorption/Ionization-Time-Of-Flight (MALDI-TOF, bioMérieux) and by sequencing the gene coding for the 16S ribosomal RNA subunit when discrepancies were observed between phenotypic characteristics and MALDI-TOF. Antibiotic sensitivity profiling was determined using the automated VITEK®2 system (bioMérieux). Twenty-one isolates were obtained, of which Klebsiella pneumoniae was the most frequent (23.8%), and 34% of the isolates showed decreased sensitivity to beta-lactam antibiotics such as cefoxitin, ampicillin/sulbactam and piperacillin/tazobactam. These findings suggest that leachates from landfills could be a reservoir of pathogenic bacteria carrying antibiotic resistance determinants, so periodic microbiological characterization of these effluents should be performed, promoting the One Health approach.

Municipal solid waste, an overlooked route of transmission for the severe acute respiratory syndrome coronavirus 2: a review

Municipal solid waste could potentially transmit human pathogens during the collection, transport, handling, and disposal of waste. Workers and residents living in the vicinity of municipal solid waste collection or disposal sites are particularly susceptible, especially unprotected workers and waste pickers. Recent evidence suggests that municipal solid waste-mediated transmission can spread the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to humans. Such risks, however, have received little attention from public health authorities so far and may present an under-investigated transmission route for SARS-CoV-2 and other infectious agents during pandemics. In this review, we provide a retrospective analysis of the challenges, practices, and policies on municipal solid waste management during the current pandemic, and scrutinize the recent case reports on the municipal solid waste-mediated transmission of the coronavirus disease 2019 (COVID-19). We found abrupt changes in quantity and composition of municipal solid wastes during the COVID-19. We detail pathways of exposure to SARS-CoV-2 and other pathogens carried on municipal solid wastes. We disclose evidence of pathogenic transmission by municipal solid waste to humans and animals. Assessments of current policies, gaps, and voluntary actions taken on municipal solid waste handling and disposal in the current pandemic are presented. We propose risk mitigation strategies and research priorities to alleviate the risk for humans and vectors exposed to municipal solid wastes.

Non-target, suspect and target screening of chemicals of emerging concern in landfill leachates and groundwater in Guangzhou, South China

Landfill sites have been regarded as a significant source of chemicals of emerging concern (CECs) in groundwater. However, our understanding about the compositions of CECs in landfill leachate and adjacent groundwater is still very limited. Here we investigated the CECs in landfill leachates and groundwater of Guangzhou in South China by target, suspect and non-target analysis using high-resolution mass spectrometry (HRMS). A variety of CECs (n = 242), including pharmaceuticals (n = 64), pharmaceutical intermediates (n = 18), personal care products (n = 9), food additives (n = 18), industrial chemicals (n = 82, e.g., flame retardants, plasticizers, antioxidants and catalysts), pesticides (n = 26), transformation products (n = 8) and other organic compounds (n = 17) were (tentatively) identified by non-target and suspect screening. 142 CECs were quantitated with target analysis, and among them 37, 24 and 27 CECs were detected respectively in the raw leachate (272-1780 μg/L), treated leachate (0.25-0.81 μg/L) and groundwater (0.10-53.7 μg/L). The CECs in the raw leachates were efficiently removed with the removal efficiencies greater than 88.7%. Acesulfame, bisphenol F and ketoprofen were the most abundant compounds in both treated leachate and groundwater. The CECs in groundwater was found most likely to be originated from the landfill sites. Our results highlight the importance of non-target screening in identifying CECs, and reveal the contamination risk of groundwater by landfill leachate.

The Sources and Potential Hosts Identification of Antibiotic Resistance Genes in the Yellow River, Revealed by Metagenomic Analysis

The fate of antibiotic resistance genes (ARGs) has been revealed in various environmental media in recent years. Namely, the emergence of genes that resist colistin and carbapenems has attracted wide attention. However, the pollution condition of ARGs and sources in the Yellow River is still little understood, despite the river being the second longest in China. The present study determined the levels of ARG pollution in the Henan section of the Yellow River and evaluated the role of the aquaculture industry in the spread of ARGs. As revealed by the results, a total of 9 types of ARGs were detected in the sediments of the Yellow River, and the total ARG content in the Yellow River ranges from 7.27 to 245.45 RPKM. Sul1 and sul2 are the dominant ARGs, and the huge usage of sulfonamides, horizontal gene transfer, and wide bacteria host contribute to the prevalence of these two genes. The results of Spearman correlation analysis indicate that the breeding industry has little influence on ARGs in the Yellow River. Network analysis reveals that the opportunistic pathogen Pseudomonas is the potential host of sul1, tetG, and ANT(3'')-IIa, which can pose a risk to human health.

Occurrence, transformation, bioaccumulation, risk and analysis of pharmaceutical and personal care products from wastewater: a review

Almost all aspects of society from food security to disease control and prevention have benefited from pharmaceutical and personal care products, yet these products are a major source of contamination that ends up in wastewater and ecosystems. This issue has been sharply accentuated during the coronavirus disease pandemic 2019 (COVID-19) due to the higher use of disinfectants and other products. Here we review pharmaceutical and personal care products with focus on their occurrence in the environment, detection, risk, and removal.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10311-022-01498-7.