Aquatic Ecosystems Research Articles

The response to and rejection of Brian Ford’s Too Big to Walk, a 21st century effort to reinstate the aquatic dinosaur hypothesis

ABSTRACT In magazine articles, a BBC Radio 4 interview and the book Too Big To Walk, Brian Ford argued that the dinosaurs of the Mesozoic were not adapted for terrestrial life, but were aquatic. Bemusement and rejection were expressed by palaeontologists, in part because evidence contradicts Ford’s proposal, but also because the aquatic paradigm underwent testing and rejection during the 20th century. Evaluation of the case as presented by Ford reiterates the fact that non-bird dinosaurs as a whole were unsuited for aquatic life; this does not contradict proposals that certain groups (like Spinosauridae) or species (like Spinosaurus aegyptiacus) were amphibious or aquatic. Ford framed the reaction to his proposal as a demonstration of the palaeontological community’s insistence that outside views are unwelcome and used a ‘post-truth’ narrative in promoting his hypothesis. Ford relied on the belittling and dismissal of expert voices, the employment of ‘alternative facts’, inaccurate reporting of pertinent events, and unironic use of terms like ‘fake news’. In this article, I review Ford’s discussion of the aquatic dinosaur conversation and report events as witnessed via my direct involvement.

Integrated time-series analysis of remote sensing imagery and crowdsourced data to monitor water hyacinth (Eichhornia crassipes) in the Orontes (asi) River

ABSTRACT Invasive plants are a serious global issue due to the damage they cause to aquatic ecosystems. In recent years, the Orontes River has been struggling with water hyacinth, an invasive species that completely covers the river’s surface. Within the scope of this study, the history of water hyacinth in the Orontes River was examined using remote sensing and crowdsourced data. Optical data with different spatial resolutions (Landsat-8 OLI and Sentinel-2 MSI) and Sentinel-1 SAR satellite data were used as remote sensing data. Google News, used as crowdsourced data, was compared with time series obtained from satellite data, emphasizing the complementary role of all three data types (optical, SAR and crowdsourced). Using PlanetScope Dove satellite data, the growth, development and extinction cycle of water hyacinth within a year were investigated according to water hyacinth density. In line with the results obtained, it is revealed that the water hyacinth began to appear after June, grew in the summer months, reached its peak in October–November, and disappeared after November with the increasing precipitation. This study is the first to examine water hyacinths in the Orontes River using remote sensing and crowdsourced data, and the results will guide decision-makers in the fight against water hyacinths.

Physico-Chemical Analysis of Textile Effluents from Bagru, Jaipur (Rajasthan, India): Implications for Environmental Impact and Treatment Needs

The textile industry is one of the largest water polluters worldwide. The coloured and bad odour effluent discharged from such industries pollutes not only the water bodies but also affects groundwater quality. In the present study, thirty-five water samples were collected from different dyeing units of the Bagru textile area (Rajasthan, India) famous for using natural dyes for textile processing. The physico-chemical analysis of these water samples shows that all parameters exceeded the permitted range recommended by the Central Pollution Control Board (CPCB) and World Health Organization (WHO). The analysis revealed the use of synthetic dyes in Bagru's textile industry for dyeing and printing. Based on the estimated characteristics, these textile effluents must be properly treated before releasing into the environment as the discharge of untreated effluents into local water bodies leads to significant water pollution, adversely affecting aquatic ecosystems and biodiversity. Additionally, contaminants can permeate the soil, compromising agricultural productivity and food safety. The air quality is also compromised due to the release of volatile organic compounds (VOCs) during the dyeing process, posing respiratory risks to nearby communities. This research underscores the urgent need for improved waste management practices and regulatory measures to mitigate the adverse environmental effects associated with synthetic dyes in Bagru's textile industry.

Flocs as vectors for microplastics in the aquatic environment

AbstractMicroplastics (MPs) are an important component of suspended particulate matter in aquatic environments with two main transport modes, that is, as individual entities or in flocs. Despite its importance to MP pollution management, understanding and predicting MP flocculation remains a challenge. In this Article, we combined a meta-analysis of published data (>2,000 measurements) with new experimental data (>4,000 measurements) to investigate which size fraction of MPs can be incorporated into and transported by flocs in the aquatic environment. The size relationship between MPs and flocs can be used to predict the flocculation of MPs in various aquatic environments, and we have proposed a mathematical model to show that small MPs (<162 µm) are predominantly transported as flocs, regardless of the physicochemical characteristics of the MPs or water body. This provides valuable information to predict the transport modes of MPs, presenting a critical insight for multiple environmental settings and future pollution control strategies.

Theoretical and experimental study on efficient thorium removal from aquatic environment using phosphate-modified graphene oxide polymeric beads

AbstractThorium is an element of immense importance in nuclear industry due to lower environmental impact compared to fossil fuels and conventional nuclear power. In the present study, highly selective adsorption of Th4+ on phosphate modified graphene oxide polymeric beads was investigated. The interaction of –PO4, –OH and –O– functional groups of graphene oxide with thorium ion was thoroughly investigated using Density Functional Theory. The adsorption induced density difference was utilized to investigate the bonding characteristics. The affinity of the Th4+ ions was obtained as –PO4 > –OH > –O– group of the phosphate modified graphene oxide. Phosphate modified Graphene oxide embedded in Calcium alginate matrix was characterized using ATR-FTIR, XRD, SEM and Raman spectroscopy. Highly efficient (> 93%) uptake of thorium at pH 5 with fast rate of sorption (< 5 min) was observed in the batch sorption studies.

CONTRIBUIÇÕES DA FISIOTERAPIA AQUÁTICA: REABILITAÇÃO EM PACIENTES COM LESÃO MEDULAR ESPINHAL TRAUMÁTICA

Aquatic Physical Therapy (APT) has been reported as applicable in various specialties within the physiotherapy field, culminating in rehabilitation procedures, especially after Spinal Cord Injury (SCI), with beneficial results for individuals with this condition. It tends to be more effective in restoring some or all movement, initially with plegia, presenting a decrease and even absence of strength and balance post-trauma in the vertebral column region, leading to spinal cord injury. The aquatic environment provides the patient with a bombardment of sensory-motor stimuli, further activating neuroplasticity in rehabilitation, as well as reducing pain, providing relaxation of all muscles, and increasing blood supply to the muscles. In addition to being a therapy in a safe environment, an important factor is the reduction of joint impact and improvement in venous return, making it possible to recover movements. Objective: To understand the contributions of aquatic physiotherapy in functional rehabilitation in (SCI). Methodology: Based on bibliographic research, using the electronic databases Bireme, PubMed, and Scielo, with articles published from 2000 onwards. Conclusion: Aquatic physiotherapy and its benefits in health recovery, achieved through the physical properties of water, have been studied since the time of Hippocrates, which, combined with physiotherapy treatment protocols, promote better functional rehabilitation for patients with (SCI).

Appraising the potentials of reusing plastic bottles as building blocks for housing construction at Paipe village Abuja Nigeria

Plastic bottles package a multitude of commodities consumed worldwide. Upon consumption of the commodity, the disposed plastic bottles accumulate as waste, having impacts on both the aquatic and terrestrial environment. In a bid to convert such waste to wealth, plastic bottles are creatively reused for different applications, such as pedestrian bridge boats and street furniture, amongst others. Another application of reusing plastic bottles is their serving as building blocks for housing construction. Reports and research in Nigeria confirm the proliferation of plastic bottles littering the environment, which if reused in housing construction has the potential to contribute to achieving both UN Sustainable Development Goals (SDG) 11 (making human settlements sustainable) and 12 (ensuring sustainable consumption and production). Although Nigeria is traced to being the first country in Africa to reuse plastic bottles in housing construction, not much research output exists from practitioners’ experience on the potentials of reusing plastic bottles as a sustainable construction material as practiced in countries like Vietnam, India, and the Philippines, among others. As such, this study investigates the potential factors driving the practice of reusing plastic bottles in Nigeria with a view to ascertaining the satisfaction derived from the practice for sustainable housing construction. Primary data was collected using a structured questionnaire from 41 respondents identified as having experience in using plastic bottles in construction (5 staffs of Awonto Konsult as well as 36 staffs of Brains and Hammers Construction). Data was analysed descriptively using both IBM SPSS Statistics 23 as well as MS Excel to compute the Mean Score as well as the Relative Satisfaction Index (RSI). Only 30 questionnaires were successfully retrieved and fully answered. Amongst the 10 potential factors studied driving reusing plastic bottles, results show that almost all respondents tend to be ‘satisfied’ with both ‘strength and stability’ (having a Mean Value of 4.70 and RSI of 0.94) as well as ‘durability’ (having a Mean Value of 4.50; RSI of 0.90) of buildings built with plastic bottles. These two factors recorded the highest ‘satisfaction’ ratings, leaning towards ‘very satisfied’. Regarding the factor ‘fire resistance’ of buildings built with plastic bottles (having a Mean Value of 3.40; RSI of 0.68), results reveal that 50 percent of the respondents are ‘unsure’ if it is a satisfactory factor driving reusing plastic bottles or not. The study found that the satisfaction ratings of technical and environmental factors have higher appeal to respondents compared to health and safety and also financial factors. It is recommended that Awonto Konsult and also Brains and Hammers Construction invest more in information related to the fire resistance of plastic bottles used in construction because fire outbreaks pose great threats to buildings. Equally, wider empirical research on plastic bottle wastes, if undertaken, could support the development of policies for waste management, particularly in developing countries. This research has the potential to convert waste into wealth in a bid to minimising environmental impacts of disposed plastic bottles as well as contribute to sustainable materials, particularly for rural housing. Since this study was based on a survey, experimental studies of potentials driving the reuse of plastic bottles in housing construction will reveal results that could enable more sustainable housing construction in Nigeria.

Characteristics and pollution indices of leachates from municipal solid waste landfills in Iranian metropolises and their implications for MSW management

Leachate from municipal solid waste landfills poses a significant threat to aquatic ecosystems due to poor management practices. This study evaluated thirty leachate samples from Iranian metropolises using the Leachate Pollution Index (LPI). Various parameters, including BOD₅, COD, TDS, pH, EC, heavy metals, turbidity, PAHs, phthalates, and humic acid, were analysed. The BOD₅ levels ranged from 350 to 20,000 mg/L, and the COD levels ranged from 2,000 to 90,000 mg/L. The TDS content varied between 14.7 and 67 g/L, while the turbidity ranged from 15 to 186 NTU. Heavy metals were present but within standard limits. The phthalate concentrations ranged from 6 to 150.8 mg/L, and the humic acid concentrations ranged from 135 to 2,200 mg/L. Naphthalene was the most frequent hydrocarbon detected. The LPIs were less than 30 for all the samples, with the highest in Ahvaz and the lowest in the treated samples from Tehran. This study highlights the presence of persistent organic and hazardous contaminants in Iran’s municipal landfills, emphasizing the need for effective leachate treatment and improved waste management practices. Enhanced final disposal methods, increased waste recovery, and improved solid residue separation are crucial for preventing further leachate production and environmental contamination.

Metagenomic Analysis of Microbial Diversity in the Moroccan Coastal Water of the Gibraltar Strait

Coastal waters are known for higher productivity and organic matter levels, which support a high diversity and abundance of microorganisms compared to some aquatic environments. The characterization of marine microbiomes can provide valuable information for evaluating the sustainability of coastal waters that are increasingly subjected to environmental and human impacts. Our study is the first metagenomic study realized on Moroccan Mediterranean coastal seawater. We analyzed and described the Gibraltar Detroit marine microbiome taxonomic and functional profiling using MG-RAST software. Shotgun sequencing revealed a predominance of bacterial taxa, particularly the Proteobacteria (57.29%) and Bacteroidetes (27.06%) phyla, alongside notable populations of eukaryotes, viruses, and archaea. Alphaproteobacteria and Gammaproteobacteria emerged as the dominant bacterial classes, while Flavobacteria represented a significant portion of Bacteroidetes. Functional profiling of the microbial community highlighted a wide array of metabolic pathways, emphasizing genes related to carbohydrate metabolism, amino acid synthesis, and protein processing. The marine microbiome exhibited essential biogeochemical activities, particularly in nitrogen, sulfur, and carbon cycles, with notable pathways including denitrification, thiosulfate oxidation, and carbon fixation. This functional diversity underlines the microbiome’s role in sustaining ecosystem health through nutrient cycling and organic matter degradation. Our findings offer a crucial baseline for understanding microbial community structure and resilience in Mediterranean coastal ecosystems, with implications for assessing future environmental and anthropogenic impacts on these microbial dynamics.

Recreational Water Safety in Hotels: Lessons from the COVID-19 Pandemic and the Way Forward for a Safe Aquatic Environment

The recreational waters of hotels are widely used by locals and travelers all around the world, and this impacts public health. In this regard, the WHO frequently offers recommendations—especially during the COVID-19 era—that operators and managers of public pools, hot tubs, or splash pads should continue to follow. This study aims to evaluate the microbiological results of COVID-19 sanitation protocols in recreational waters in hotels during the summer periods post-COVID-19 (2020–2022) and compare them with those pre-COVID-19 (2019). Of the samples tested during the pre-pandemic period, less than 1/5 were positive for total coliforms, common aerobic bacteria, and P. aeruginosa, while less than 3% of the samples tested were positive for E. coli. During the pandemic years, the percentages dropped by half for total coliforms, common aerobic bacteria, and E. coli, while only the percentage for P. aeruginosa remained the same. The relative risk (RR) for the presence of P. aeruginosa in recreational waters was greatly affected by chlorine levels, pH values, and water temperature. Our results elucidate the impact of sanitation protocols on the safety of recreational waters in hotels during public health crises. Moreover, the challenges operators face in maintaining long-term implementation of these protocols are highlighted, which in turn dictates the appropriate choice of preventive and applicable measures to ensure health and safety.

A critical review on heavy metal contamination in aquatic food webs by edible fish species: a special case concerning Bangladesh.

Heavy metals (HMs) are ubiquitous in terrestrial and aquatic environments due to unplanned industrial waste discharge, the release of untreated wastewater, and improper mining activities. In particular, the concentrations of HMs are found to be higher in aquatic environments. As a result, the aquatic biota was heavily affected by HM contamination. This critical review aims to understand the sources and toxicity of HMs in commercial fish species, explore their ecological exchange, and examine the related human health challenges in Bangladesh. A modified PRISMA review technique is used in this paper to analyze the current status and research limitations of HM studies in Bangladesh fish species and their toxicity within aquatic food webs. Briefly, we searched several keywords to explore the research trend of HM concentrations and toxicity in fish species. Furthermore, potential toxicity and risk assessment of HMs through the aquatic food chain in Bangladesh were explored. On the other hand, a cross-tabulation approach was used to process the toxicity findings of HMs. Previous studies indicate that fish species can possess comparatively higher HMs than river water due to ecological exchange factors, including bioaccumulation and biotransformation. This review focuses on Bangladesh, highlighting areas for improvements and the need for further study to achieve a transparent understanding of HM deposition in fish species and the sustainable management of aquatic food chain toxicity.

Ultrafast complete dechlorination enabled by ferrous oxide/graphene oxide catalytic membranes via nanoconfinement advanced reduction

Chlorinated organic pollutants widely exist in aquatic environments and threaten human health. Catalytic approaches are proposed for their elimination, but sluggish degradation, incomplete dechlorination, and catalyst recovery remain extremely challenging. Here we show efficient dechlorination using ferrous oxide/graphene oxide catalytic membranes with strong nanoconfinement effects. Catalytic membranes are constructed by graphene oxide nanosheets with integrated ultrafine and monodisperse sub-5 nm nanoparticles through simple in-situ growth and filtration assembly. Density function theory simulation reveals that nanoconfinement effects remarkably reduce energy barriers of rate-limiting steps for iron (III)-sulfite complex dissociation to sulfite radicals and dichloroacetic acid degradation to monochloroacetic acid. Combining with nanoconfinement effects of enhancing reactants accessibility to catalysts and increasing catalyst-to-reactant ratios, the membrane achieves ultrafast and complete dechlorination of 180 µg L−1 dichloroacetic acid to chloride, with nearly 100% reduction efficiency within a record-breaking 3.9 ms, accompanied by six to seven orders of magnitude greater first-order rate constant of 51,000 min−1 than current catalysis. Meanwhile, the membranes exhibit quadrupled permeance of 48.6 L m−2 h−1 bar−1 as GO ones, because nanoparticles adjust membrane structure, chemical composition, and interlayer space. Moreover, the membranes show excellent stability over 20 cycles and universality for chlorinated organic pollutants at environmental concentrations.

Ore sulfur of Golovnin Volcano, Kunashir Island

Research subject. Hydrothermal deposits of Golovnin Caldera. Aim. To study the epithermal volcanogenic ore formation. Key points. Until now, there has been a consensus on the exogenous sedimentary (colloidal) genesis of sulfur in volcanic lakes. Our observations and microstructure studies indicate the presence of sulfur melt at the bottom of Kipyaschee Lake. Drops of this melt are carried to the surface of the lake as part of a light gray foam. The significant differences of sulfur spherules in the concentration of sulfide mineralization, in its composition, as well as in the presence or absence of numerous opal inclusions are most simply explained by the capture of droplets in various parts of the sulfur melt and their subsequent movement by a gas stream passing through the melt. Elemental sulfur condensate is formed in bottom sediments as a result of forced cooling of endogenous gas flows by lake water. The main condensation of sulfur occurs here (96% or more of the total potential of fluid sulfur). Residual condensation of sulfur occurs in the aquatic environment. Finely dispersed sulfur condensate in a mixture with water is unstable and breaks down over time with the release of hydrogen sulfide and the formation of sulfurous and sulfuric acids. The activity of bottom hydrotherms and coastal unrest prevents the formation of colloidal sulfur sediment at the bottom of lakes. In the crater depressions at the bottom of the lakes of the Golovnin Caldera, sulfidization of its melt occurs simultaneously with the condensation of sulfur itself. Gravitational deposition of sulfides in the sulfur melt leads to their enrichment of the root parts of crater depressions, where pyrite ore bodies are formed in real time. Terrestrial sulfur deposits, together with the modified rocks overlying them, demonstrate the full profile of endogenous apical oxidation under gas-hydrothermal action: sulfur and sulfur-opal rocks up the section are replaced by gypsum-jarosite rocks and, further, by an “iron hat” of limonite-cemented breccias of the dome mantle. Conclusions. Observations, microstructure studies and molecular chemical modeling indicate the endogenous condensate origin of ore sulfur in the Golovnin Caldera and exclude its exogenous sedimentary genesis.

Ecological Vulnerability of Aquatic Ecosystems—A Review

Ecological Vulnerability of Aquatic Ecosystems—A Review

Effects of dissolved organic matter from different sources on ritonavir photolysis

With the misuse of antiviral drugs, the residual levels of ritonavir (RTV) in aquatic environments continue to increase, potentially posing threats to ecosystems and human health. However, the current understanding of the photochemical behavior of RTV in water, especially the mechanism by which dissolved organic matter (DOM) from different sources affects the indirect photolysis of RTV, remains limited. This study systematically investigated the effects of DOM from different sources (including sludge, algae, dustfall, and soil, namely SL-DOM, AL-DOM, DF-DOM, and SO-DOM, respectively) on the photodegradation of RTV for the first time. DOM exhibited a dual role in RTV degradation, with SL-DOM and AL-DOM accelerating the degradation process, while DF-DOM and SO-DOM inhibited it. Direct photolysis accounted for 40–53% of the overall photodegradation, underscoring its significant contribution to the degradation process. Quenching and competitive kinetics experiments revealed that 3DOM⁎ is the dominant contributor to the indirect photolysis of RTV. Exogenous DOM (DF-DOM, SO-DOM) exhibited higher generation rate and steady-state concentraiton of 3DOM⁎, while endogenous DOM (SL-DOM, AL-DOM) exhibited higher quantum yields of 3DOM⁎ and reactivity, leading to distinct mechanisms for the indirect photodegradation of RTV. This study explored the effects of DOM from different sources on the photodegradation of RTV, providing important insights into how DOM affects the photochemical behavior and ecological risk of RTV. It also provides a reference for exploring the photochemical behavior of other drugs.

Development of engineered Zn-MOF/g-C3N4 based photoelectrochemical system for real-time sensors and removal of naproxen in wastewater

Naproxen-contaminated water may lead to the accumulation of the drug in aquatic organisms and can pose high risks to an aquatic environment and human beings. Therefore, this work aimed to develop photoelectrochemical sensing and degradation of naproxen (NPX) using zinc-metal organic framework /graphitic carbon nitride thin film-based fluorine-doped tin oxide (Zn-MOF/g-C3N4/FTO) as anode material for the sensing and degradation of naproxen (NPX). The surface morphology, structure, surface property, surface area, optical property, photocurrent, and charge transfer kinetics abilities were studied using different techniques. The nanocomposites showed a superior photocurrent response (0.815 mA cm-2) compared to the original g-C3N4 (0.328 mA cm-2). The photo-anode made of Zn-MOF@g-C3N4/FTO displayed the highest photocurrent value, indicating that the alignment of the two semiconductor bands prevented the quick recombination of electron-hole pairs. Owing to these attractive features, the Zn-MOF/g-C3N4/FTO electrode was applied for photoelectrochemical detection of NPX using chronoamperometry. Interestingly, the nanocomposites-based FTO ascribed a lower detection limit (2.3 ng l-1) with a wide linear range concentration of NPX (0.5 to 200 µg l-1). Additionally, the analytical assessment of repeatability and reproducibility demonstrated robust performance, with commendable relative standard deviations (RSD%) of 2.54 % and 2.40 %, respectively. On the other hand, a remarkable degradation efficiency of 97.52 % was attained when employing a bias potential of 0.1 V during a 2 h photoelectrocatalytic oxidation of NPX. The degradation process was primarily driven by the active participation of holes and hydroxyl radicals in ring opening and subsequent cleavage of by-products. The notable effectiveness of this degradation can be attributed to the combined and synergistic effects of both electrochemical and photocatalytic degradation techniques. The current state demonstrates its effectiveness in the photoelectrochemical sensing and removal of NPX using MOF/g-C3N4 nanocomposites-based electrode materials in wastewater.

Phytoremediation of microcystins using Myriophyllum aquaticum can prevent sublethal effects in a Neotropical freshwater catfish

Microcystins are cyanotoxins that can be produced by cyanobacteria species such as Microcystis aeruginosa. Due to the presence of microcystins in water bodies and aquatic organisms, it needs to be monitored. Furthermore, additional studies are required in the implementation of alternative and sustainable water treatment methods. The aim of this study was to investigate the potential of Myriophyllum aquaticum to prevent the harmful effects induced by M. aeruginosa aqueous extract in Rhamdia. quelen usingbiomarkers and to assess whether the plant can be suitable for phytoremediation in aquatic ecosystems. In the first experiment, R. quelen was exposed to 1 and 10 μg.L–1 of microcystins through an aqueous extract dissolved in the bioassay’s water. Second, tanks containing the same test concentrations of microcystins were treated by phytoremediation using M. aquaticum at 10 g.L–1, for 7 days. After that, treated water was used in a new bioassay with fish exposure. The results showed that phytoremediation decreased the microcystin concentration in water, and different biomarker analyses demonstrated that M. aquaticum treatment prevented DNA damage, hematological alterations, and tissue damage in R. quelen. The phytoremediation with M. aquaticum can be a sustainable and cost-effective alternative to water treatment, highlighting its role in enhancing water quality and supporting biodiversity conservation. These results support the importance of adopting more restrictive legal limits for cyanotoxins in water to protect native aquatic species and promote sustainable water resource management.

Public health concern of antimicrobial resistance and virulence determinants in E. coli isolates from oysters in Egypt

The emergence of critical-priority E. coli, carrying a wide array of resistance and virulence factors through food sources, poses a significant challenge to public health. This study aimed to investigate the potential role of oysters sold in Egypt as a source for E. coli, identify their resistance and virulence-associated gene profiles, and assess associated zoonotic risks. A total of 33 pooled fresh oyster samples were obtained from various retail fish markets in Egypt and examined bacteriologically for the presence of E. coli. Antimicrobial resistance was performed by the disk-diffusion method, and the multiple antibiotic resistance index (MAR) was calculated. All isolates were screened for extended-spectrum beta-lactamase (ESBL) (blaTEM, blaSHV, blaCTX−M, and blaOXA−1), plasmid-mediated AmpC blaCMY−2, and carbapenemases (blaKPC, blaNDM, blaVIM, and blaOXA−48) genes by Polymerase chain reaction. Moreover, the presence of virulence-encoding genes was investigated. The virulent MDR strains were clustered using R with the pheatmap package. The prevalence of E. coli was 72.7% (24 out of 33), with 66.7% of the isolates classified as multi-drug resistant, and 75% exhibited MAR values exceeding the 0.2 threshold. Different antimicrobial sensitivity phenotypes and genotype profiles were identified in E. coli isolates. The most prevalent gene detected among all isolates was blaTEM (22/24, 91.7%). Notably, all non-ESBL producers were positive for blaCMY2. Carbapenem-resistant and carbapenem-intermediate strains were carbapenemase producers, with the predominance of the blaKPC gene (11/24, 45.8%). Remarkably, twelve out of sixteen virulence genes were identified, with papC (21/24, 87.5%) and sfa (16/24, 66.7%) genes being the most prevalent. Most isolates carry virulence genes primarily associated with extra-intestinal pathogenic E. coli (ExPEC) (87.5%) and enteropathogenic (EPEC) (70.8%) pathotypes. Four E. coli isolates exhibit cluster patterns. This study provides the first insight into the emergence of virulent MDR E. coli among oysters in Egypt. It underscores the potential role of oysters as a source for disseminating these strains within aquatic ecosystems, presenting a possible threat to public health.

Profiling the bacterial microbiome diversity and assessing the potential to detect antimicrobial resistance bacteria in wastewater in Kimberley, South Africa

Wastewater treatment plants (WWTPs) are hotspots for pathogens, and can facilitate horizontal gene transfer, potentially releasing harmful genetic material and antimicrobial resistance genes into the environment. Little information exists on the composition and behavior of microbes in WWTPs, especially in developing countries. This study used environmental DNA (eDNA) techniques to examine the microbiome load of wastewater from WWTPs. The DNA was isolated from wastewater samples collected from the treatment trains of three WWTPs in Kimberley, South Africa, and the microbial diversity and composition was compared through 16 S rRNA gene sequencing. The microbes detected were of the Kingdom Bacteria, and of these, 48.27% were successfully identified to genus level. The majority of reads from the combined bacterial data fall within the class Gammaproteobacteria, which is known to adversely impact ecological and human health. Arcobacteraceae constituted 19% of the bacterial reads, which is expected as this family is widespread in aquatic environments. Interestingly, the most abundant bacterial group was Bacteroides, which contain a variety of antibiotic-resistant members. Overall, various antibiotic-resistant taxa were detected in the wastewater, indicating a concerning level of antibiotic resistance within the bacterial community. Therefore, eDNA analysis can be a valuable tool in monitoring and assessing the bacterial microbiome in wastewater, thus providing important information for the optimization and improvement of wastewater treatment systems and mitigate public health risks.

Cyanophage Engineering for Algal Blooms Control

Cyanobacteria represent a prevalent category of photosynthetic autotrophs capable of generating deleterious algal blooms, commonly known as cyanobacteria harmful algal blooms (cyanoHABs). These blooms often produce cyanotoxins, which pose risks to public health and ecosystems by contaminating surface waters and drinking water sources. Traditional treatment methods have limited effectiveness. Therefore, there is an urgent need for a new approach to effectively manage cyanoHABs. One promising approach is the use of cyanophages, which are viruses that specifically target cyanobacteria. Cyanophages serve as an effective biological control method for reducing cyanoHABs in aquatic systems. By engineering cyanophages, it is possible to develop a highly specific control strategy that minimally impacts non-target species and their propagation in the environment. This review explores the potential application of cyanophages as a strategy for controlling cyanoHABs. It includes the identification and isolation of broad-spectrum and novel cyanophages, with a specific focus on freshwater Microcystis cyanophages, highlighting their broad spectrum and high efficiency. Additionally, recent advancements in cyanophage engineering are discussed, including genome modification, functional gene identification, and the construction of artificial cyanophages. Furthermore, the current state of application is addressed. Cyanophage is a promising control strategy for effectively managing cyanoHABs in aquatic environments.