Epigenome-metabolism nexus in the retina: implications for aging and disease.

Intimate links between epigenome modifications and metabolites allude to a crucial role of cellular metabolism in transcriptional regulation. Retina, being a highly metabolic tissue, adapts by integrating inputs from genetic, epigenetic, and extracellular signals. Precise global epigenomic signatures guide development and homeostasis of the intricate retinal structure and function. Epigenomic and metabolic realignment are hallmarks of aging and highlight a link of the epigenome-metabolism nexus with aging-associated multifactorial traits affecting the retina, including age-related macular degeneration and glaucoma. Here, we focus on emerging principles of epigenomic and metabolic control of retinal gene regulation, with emphasis on their contribution to human disease. In addition, we discuss potential mitigation strategies involving lifestyle changes that target the epigenome-metabolome relationship for maintaining retinal function.

The research landscape concerning environmental factors in neurodevelopmental disorders: Endocrine disrupters and pesticides-A review.

In recent years, environmental epidemiology and toxicology have seen a growing interest in the environmental factors that contribute to the increased prevalence of neurodevelopmental disorders, with the purpose of establishing appropriate prevention strategies. A literature review was performed, and 192 articles covering the topic of endocrine disruptors and neurodevelopmental disorders were found, focusing on polychlorinated biphenyls, polybrominated diphenyl ethers, bisphenol A, and pesticides. This study contributes to analyzing their effect on the molecular mechanism in maternal and infant thyroid function, essential for infant neurodevelopment, and whose alteration has been associated with various neurodevelopmental disorders. The results provide scientific evidence of the association that exists between the environmental neurotoxins and various neurodevelopmental disorders. In addition, other possible molecular mechanisms by which pesticides and endocrine disruptors may be associated with neurodevelopmental disorders are being discussed.

Environmental Factors Associated with Risk of Crohn's Disease Development in the Crohn's and Colitis Canada - Genetic, Environmental, Microbial Project.

BACKGROUND & AIMS: To date, it is unclear how environmental factors influence Crohn's disease (CD) risk and how they interact with biological processes. This study investigates the association between environmental exposures and CD risk and evaluates their association with pre-disease biomarkers. METHODS: We studied 4289 healthy first-degree relatives (FDRs) of patients with CD from the Crohn's and Colitis Canada - Genetic, Environmental, Microbial (CCC-GEM) project. Regression models identified environmental factors associated with future CD onset and their association with pre-disease biological factors, including altered intestinal permeability measured by urinary fractional excretion of lactulose to mannitol ratio (LMR); gut inflammation via fecal calprotectin (FCP) levels; and fecal microbiome composition through 16S rRNA sequencing. RESULTS: Over a 5.62-year median follow-up, 86 FDRs developed CD. Living with a dog between ages 5 and 15 (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.40-0.96; P = .034), and living with a large family size in the first year of life (HR, 0.43; 95% CI, 0.21-0.85; P = .016) were associated with decreased CD risk, whereas having a bird at the time of recruitment (HR, 2.78; 95% CI, 1.36-5.68; P = .005) was associated with an increased CD risk. Furthermore, living with a dog was associated with reduced LMR, altered relative abundance of multiple bacterial genera, and increased Chao1 diversity, whereas bird owners had higher FCP levels. Large family during participants' first year of life was associated with altered microbiota composition without affecting FCP or LMR. CONCLUSION: This study identifies environmental variables associated with CD risk. These variables were also associated with altered barrier function, subclinical inflammation, and gut microbiome composition shifts, suggesting potential roles in CD pathogenesis.

Let-7c-5p associate with inhibition of phenobarbital-induced cell proliferation in human palate cells.

Cleft palate (CP) is one of the most common congenital diseases, and is accompanied by a complicated etiology. Medical exposure in women is among one of the reasons leading to CP. Recently, it has been reported that microRNA (miRNA) plays a crucial role in palate formation and the disruption of miRNA that influence the development of CP. Although association with pharmaceuticals and miRNAs were suggested, it has remained largely unknow. The aim of the current investigation is to elucidate upon the miRNA associated with the inhibition of phenobarbital (PB)-induced cell proliferation in human embryonic palatal mesenchymal (HEPM) cells. We showed that PB inhibited HEPM cell viability in a dose-dependent manner. We demonstrated that PB treatment suppressed cyclin-D1 expression in HEPM cells. Furthermore, PB upregulated let-7c-5p expression and downregulated the expression of two downstream genes (BACH1 and PAX3). Finally, we demonstrated that the let-7c-5p inhibitor alleviated PB-induced inhibition of cell proliferation and altered BACH1 and PAX3 expression levels. These results suggest that PB suppresses cell viability by modulating let-7c-5p expression.

Assessing the climate adaptive potential of imported Chili in comparison with local cultivars through germination performance analysis.

BACKGROUND: The study offers insightful information about the adaptability of local and imported Chili cultivars. This experiment examines how three different chili cultivars Tanjung, Unpad, and Osaka perform in the germination and early growth phases while considering a wide range of environmental conditions. Research conducted in Jatinangor, Sumedang Regency, Indonesia, highlights the differences between cultivars and the varied possibilities for adaptability each variation possesses. RESULTS: Among them, Tanjung stands out as the most promising cultivar; its robust performance is demonstrated by its high germination index 91.7. Notable features of Osaka include the highest biomass output (1.429 g), the best water usage efficiency (WUE) at 0.015 g/liter, and the best distribution uniformity (91.2%) and application efficiency (73.6%) under different irrigation conditions. Tanjung's competitiveness is further evidenced by the fact that it trails Osaka closely on several metrics. Lower performance across criteria for Unpad suggests possible issues with flexibility. CONCLUSION: The value of this information becomes apparent when it comes to well-informed breeding programs and cultivation techniques, especially considering uncertain climate patterns and global climate change. This research contributes significantly to the body of knowledge, enabling well-informed choices for environmentally dynamic, sustainable chili farming.

Seed germination ecology of endangered plant Horsfieldia hainanensis Merr. In China.

BACKGROUND: Horsfieldia hainanensis Merr., an indicator species of China's humid tropical rainforests, is endangered due to difficulties with population regeneration. In this study, the biological characteristics and germination adaptability of the seeds were studied for the first time, in order to provide a basis for analyzing the causes of endangerment and strategies for the artificial cultivation of H. hainanensis. The effects of biological characteristics (population, arils, seed coat, seed weight, seed moisture content) and environmental factors (temperature, light, drought, substrate, burial depth) on seed germination and seedling growth of H. hainanensis were studied. RESULTS AND DISCUSSION: The fruits were found to be capsules containing seeds wrapped in a pericarp and fleshy aril, which provide protection and assist in seed dispersal, but also pose risks to the seeds, as the peel and fleshy aril can become moldy under high temperature and humidity conditions. There were significant differences in fruit morphology and germination characteristics among different populations, and the seed quality of populations in Niandian village, Daxin County, Chongzuo City, Guangxi Zhuang Autonomous Region was better. The arils significantly inhibited seed germination, the germination of large seeds was better, and seedling growth from medium seeds was superior. H. hainanensis seeds were sensitive to dehydration, and intolerant to drought and low temperature, which is typical of recalcitrant seeds. The seeds are suitable for germination on a moist substrate surface with good water retention and breathability at 30-35℃.

Community assembly of organisms regulates soil microbial functional potential through dual mechanisms.

Unraveling the influence of community assembly processes on soil ecosystem functioning presents a major challenge in the field of theoretical ecology, as it has received limited attention. Here, we used a series of long-term experiments spanning over 25 years to explore the assembly processes of bacterial, fungal, protist, and nematode communities using high-throughput sequencing. We characterized the soil microbial functional potential by the abundance of microbial genes associated with carbon, nitrogen, phosphorus, and sulfur cycling using GeoChip-based functional gene profiling, and determined how the assembly processes of organism groups regulate soil microbial functional potential through community diversity and network stability. Our results indicated that balanced fertilization (NPK) treatment improved the stochastic assembly of bacterial, fungal, and protist communities compared to phosphorus-deficient fertilization (NK) treatment. However, there was a nonsignificant increase in the normalized stochasticity ratio of the nematode community in response to fertilization across sites. Our findings emphasized that soil environmental factors influenced the assembly processes of the biotic community, which regulated soil microbial functional potential through dual mechanisms. One mechanism indicated that the high phosphorus levels and low soil nutrient stoichiometry may increase the stochasticity of bacterial, fungal, and protist communities and the determinism of the nematode community under NPK treatment, ultimately enhancing soil microbial functional potential by reinforcing the network stability of the biotic community. The other mechanism indicated that the low phosphorus levels and high soil nutrient stoichiometry may increase the stochastic process of the bacterial community and the determinism of the fungal, protist, and nematode communities under NK treatment, thereby enhancing soil microbial functional potential by improving the ß-diversity of the biotic community. Taken together, these results provide valuable insights into the mechanisms underlying the assembly processes of the biotic community that regulate ecosystem functioning.

Analyzing socio-environmental determinants of bone and soft tissue cancer in Indonesia.

BACKGROUND: This study is designed to explore the potential impact of individual and environmental residential factors as risk determinants for bone and soft tissue cancers, with a particular focus on the Indonesian context. While it is widely recognized that our living environment can significantly influence cancer development, there has been a notable scarcity of research into how specific living environment characteristics relate to the risk of bone and soft tissue cancers. METHODS: In a cross-sectional study, we analyzed the medical records of oncology patients treated at Prof. Suharso National Referral Orthopedic Hospital. The study aimed to assess tumor malignancy levels and explore the relationships with socio-environmental variables, including gender, distance from the sea, sunrise time, altitude, and population density. Data were gathered in 2020 from diverse sources, including medical records, Google Earth, and local statistical centers. The statistical analyses employed Chi-square and logistic regression techniques with the support of Predictive Analytics SoftWare (PASW) Statistics 18. RESULTS: Both bivariate and multivariate analyses revealed two significant factors associated with the occurrence of bone and soft tissue cancer. Age exhibited a statistically significant influence (OR of 5.345 and a p-value of 0.000 < 0.05), indicating a robust connection between cancer development and age. Additionally, residing within a distance of less than 14 km from the sea significantly affected the likelihood of bone and soft tissue cancers OR 5.604 and p-value (0.001 < 0.05). CONCLUSIONS: The study underscores the strong association between age and the development of these cancers, emphasizing the need for heightened vigilance and screening measures in older populations. Moreover, proximity to the sea emerges as another noteworthy factor influencing cancer risk, suggesting potential environmental factors at play. These results highlight the multifaceted nature of cancer causation and underscore the importance of considering socio-environmental variables when assessing cancer risk factors. Such insights can inform more targeted prevention and early detection strategies, ultimately contributing to improved cancer management and patient outcomes.

Thyroid hormone concentrations in female baboons: Metabolic consequences of living in a highly seasonal environment.

How female mammals adapt metabolically in response to environmental variation remains understudied in the wild, because direct measures of metabolic activity are difficult to obtain in wild populations. However, recent advances in the non-invasive measurement of fecal thyroid hormones, triiodothyronine (T3), an important regulator of metabolism, provide an opportunity to understand how female baboons living in the harsh Amboseli ecosystem in southern Kenya adapt to environmental variability and escape strict reproductive seasonality. Specifically, we assessed how a female's activity budget, diet, and concentrations of fecal T3 metabolites (mT3) changed over the course of the year and between years. We then tested which of several environmental variables (season, rainfall, and temperature) and behavioral variables (female activity budget and diet) best predicted mT3 concentrations. Finally, we determined if two important reproductive events - onset of ovarian cycling and conception of an offspring - were preceded by changes in female mT3 concentrations. We found female baboons' mT3 concentrations varied markedly across the year and between years as a function of environmental conditions. Further, changes in a female's behavior and diet only partially mediated the metabolic response to the environment. Finally, mT3 concentrations increased in the weeks prior to menarche and cycling resumption, regardless of the month or season in which cycling started. This pattern indicates that metabolic activation may be an indicator of reproductive readiness in female baboons as their energy balance is restored.

Bayesian spatio-temporal analysis of malaria prevalence in children between 2 and 10 years of age in Gabon.

BACKGROUND: Gabon still bears significant malaria burden despite numerous efforts. To reduce this burden, policy-makers need strategies to design effective interventions. Besides, malaria distribution is well known to be related to the meteorological conditions. In Gabon, there is limited knowledge of the spatio-temporal effect or the environmental factors on this distribution. This study aimed to investigate on the spatio-temporal effects and environmental factors on the distribution of malaria prevalence among children 2-10 years of age in Gabon. METHODS: The study used cross-sectional data from the Demographic Health Survey (DHS) carried out in 2000, 2005, 2010, and 2015. The malaria prevalence was obtained by considering the weighting scheme and using the space-time smoothing model. Spatial autocorrelation was inferred using the Moran's I index, and hotspots were identified with the local statistic Getis-Ord General Gi. For the effect of covariates on the prevalence, several spatial methods implemented in the Integrated Nested Laplace Approximation (INLA) approach using Stochastic Partial Differential Equations (SPDE) were compared. RESULTS: The study considered 336 clusters, with 153 (46%) in rural and 183 (54%) in urban areas. The prevalence was highest in the Estuaire province in 2000, reaching 46%. It decreased until 2010, exhibiting strong spatial correlation (P < 0.001), decreasing slowly with distance. Hotspots were identified in north-western and western Gabon. Using the Spatial Durbin Error Model (SDEM), the relationship between the prevalence and insecticide-treated bed nets (ITNs) coverage was decreasing after 20% of coverage. The prevalence in a cluster decreased significantly with the increase per percentage of ITNs coverage in the nearby clusters, and per degree Celsius of day land surface temperature in the same cluster. It slightly increased with the number of wet days and mean temperature per month in neighbouring clusters. CONCLUSIONS: In summary, this study showed evidence of strong spatial effect influencing malaria prevalence in household clusters. Increasing ITN coverage by 20% and prioritizing hotspots are essential policy recommendations. The effects of environmental factors should be considered, and collaboration with the national meteorological department (DGM) for early warning systems is needed.

Assessment of environmental and spatial factors influencing the establishment of Anopheles gambiae larval habitats in the malaria endemic province of Woleu-Ntem, northern Gabon.

BACKGROUND: This study aimed to assess the spatial distribution of Anopheles mosquito larval habitats and the environmental factors associated with them, as a prerequisite for the implementation of larviciding. METHODS: The study was conducted in December 2021, during the transition period between the end of the short rainy season (September-November) and the short dry season (December-February). Physical, biological, and land cover data were integrated with entomological observations to collect Anopheles larvae in three major towns: Mitzic, Oyem, and Bitam, using the "dipping" method during the transition from rainy to dry season. The collected larvae were then reared in a field laboratory established for the study period. After the Anopheles mosquitoes had emerged, their species were identified using appropriate morphological taxonomic keys. To determine the influence of environmental factors on the breeding of Anopheles mosquitoes, multiple-factor analysis (MFA) and a binomial generalized linear model were used. RESULTS: According to the study, only 33.1% out of the 284 larval habitats examined were found to be positive for Anopheles larvae, which were primarily identified as belonging to the Anopheles gambiae complex. The findings of the research suggested that the presence of An. gambiae complex larvae in larval habitats was associated with various significant factors such as higher urbanization, the size and type of the larval habitats (pools and puddles), co-occurrence with Culex and Aedes larvae, hot spots in ambient temperature, moderate rainfall, and land use patterns. CONCLUSIONS: The results of this research mark the initiation of a focused vector control plan that aims to eradicate or lessen the larval habitats of An. gambiae mosquitoes in Gabon's Woleu Ntem province. This approach deals with the root causes of malaria transmission through larvae and is consistent with the World Health Organization's (WHO) worldwide objective to decrease malaria prevalence in regions where it is endemic.

Socio-environmental predictors of diabetes incidence disparities in Tanzania mainland: a comparison of regression models for count data.

BACKGROUND: Diabetes is one of the top four non-communicable diseases that cause death and illness to many people around the world. This study aims to use an efficient count data model to estimate socio-environmental factors associated with diabetes incidences in Tanzania mainland, addressing lack of evidence on the efficient count data model for estimating factors associated with disease incidences disparities. METHODS: This study analyzed diabetes counts in 184 Tanzania mainland councils collected in 2020. The study applied generalized Poisson, negative binomial, and Poisson count data models and evaluated their adequacy using information criteria and Pearson chi-square values. RESULTS: The data were over-dispersed, as evidenced by the mean and variance values and the positively skewed histograms. The results revealed uneven distribution of diabetes incidence across geographical locations, with northern and urban councils having more cases. Factors like population, GDP, and hospital numbers were associated with diabetes counts. The GP model performed better than NB and Poisson models. CONCLUSION: The occurrence of diabetes can be attributed to geographical locations. To address this public health issue, environmental interventions can be implemented. Additionally, the generalized Poisson model is an effective tool for analyzing health information system count data across different population subgroups.

The role of the environment in allergic skin disease.

PURPOSE OF REVIEW: This paper explores how environmental factors influence allergic skin diseases, including atopic dermatitis (AD), contact dermatitis (CD), urticaria, angioedema, and reactions to drugs and insect bites. RECENT FINDINGS: Research indicates a significant impact of environmental elements on allergic skin diseases. High air pollution levels exacerbate symptoms, while climate change contributes to increased skin barrier dysfunction, particularly affecting AD. Allergen prevalence is influenced by climate and pollution. Irritants, like those in detergents and cosmetics, play a major role in CD. Plants also contribute, causing various skin reactions. Understanding the interplay between environmental factors and allergic skin diseases is crucial for effective management. Physicians must address these factors to support patient well-being and promote skin health amidst environmental changes.

Environmental predictors of Escherichia coli concentration at marine beaches in Vancouver, Canada: a Bayesian mixed-effects modelling analysis.

Understanding historical environmental determinants associated with the risk of elevated marine water contamination could enhance monitoring marine beaches in a Canadian setting, which can also inform predictive marine water quality models and ongoing climate change preparedness efforts. This study aimed to assess the combination of environmental factors that best predicts Escherichia coli (E. coli) concentration at public beaches in Metro Vancouver, British Columbia, by combining the region's microbial water quality data and publicly available environmental data from 2013 to 2021. We developed a Bayesian log-normal mixed-effects regression model to evaluate predictors of geometric E. coli concentrations at 15 beaches in the Metro Vancouver Region. We identified that higher levels of geometric mean E. coli levels were predicted by higher previous sample day E. coli concentrations, higher rainfall in the preceding 48 h, and higher 24-h average air temperature at the median or higher levels of the 24-h mean ultraviolet (UV) index. In contrast, higher levels of mean salinity were predicted to result in lower levels of E. coli. Finally, we determined that the average effects of the predictors varied highly by beach. Our findings could form the basis for building real-time predictive marine water quality models to enable more timely beach management decision-making.

Impacts of environmental factors on the aetiological diagnosis and disease severity of community-acquired pneumonia in China: a multicentre, hospital-based, observational study.

Environmental exposures are known to be associated with pathogen transmission and immune impairment, but the association of exposures with aetiology and severity of community-acquired pneumonia (CAP) are unclear. A retrospective observational study was conducted at nine hospitals in eight provinces in China from 2014 to 2019. CAP patients were recruited according to inclusion criteria, and respiratory samples were screened for 33 respiratory pathogens using molecular test methods. Sociodemographic, environmental and clinical factors were used to analyze the association with pathogen detection and disease severity by logistic regression models combined with distributed lag nonlinear models. A total of 3323 CAP patients were included, with 709 (21.3%) having severe illness. 2064 (62.1%) patients were positive for at least one pathogen. More severe patients were found in positive group. After adjusting for confounders, particulate matter (PM) 2.5 and 8-h ozone (O3-8h) were significant association at specific lag periods with detection of influenza viruses and Klebsiella pneumoniae respectively. PM10 and carbon monoxide (CO) showed cumulative effect with severe CAP. Pollutants exposures, especially PM, O3-8h, and CO should be considered in pathogen detection and severity of CAP to improve the clinical aetiological and disease severity diagnosis.

Geographical Disparities in Lung Cancer in Canada: A Review.

PURPOSE OF REVIEW: The eastern provinces of Canada exhibit a heightened prevalence and mortality rate of lung cancer compared to their western counterparts. While established risk factors for lung cancer exist in Canada, there remains ambiguity regarding the underlying provincial and territorial trends. This review aims to identify and analyze potential contributors to healthcare inequality, guiding policymakers towards a strategic and sustainable approach at the provincial level. RECENT FINDINGS: Existing studies emphasize the significant roles played by socio-economic and environmental factors in influencing lung cancer disparities across Canadian provinces. However, a noticeable research gap persists, particularly in systematically examining the factors that amplify geographical disparities in lung cancer incidence and mortality rates within Canada. This review underscores the disparities in lung cancer prevalence and mortality rates between eastern and western Canadian provinces. While socio-economic and environmental factors have been identified as influential, there is an evident need for further research to comprehensively understand and address the underlying contributors to these geographical discrepancies.

Individual- and community-level social determinants of health are associated with cognition in older adults with focal epilepsy.

OBJECTIVE: Epilepsy is associated with significant health disparities, including access to specialized care and adverse outcomes that have been associated with several social determinants of health (SDOH). We sought to examine the relationship between individual- and community-level SDOH and cognitive outcomes in older adults with epilepsy. MATERIALS AND METHODS: We collected clinical, SDOH, and neuropsychological data in 57 older adults with epilepsy. Individual-level SDOH included patient factors (quality of education, income, insurance, marital status) and early-life environmental factors (parental education and occupation, childhood employment). Neighborhood deprivation was measured with the Area Deprivation Index (ADI). Stepwise regressions were conducted to examine the independent contribution of individual-level SDOH to cognitive performance, and Spearman rho correlations were conducted to examine the relationship between ADI and cognitive performance. The SDOH profiles of patients who met the criteria for cognitive impairment were examined. RESULTS: After controlling for clinical variables, patient factors (public health insurance, poorer quality of education) and early-life environmental factors (lower mother's education, lower father's and mother's occupational complexity, history of childhood employment) were significant predictors of lower performance on measures of global cognition, verbal learning and memory, processing speed, and executive function. Higher ADI values (greater disadvantage) were associated with lower scores on global cognitive measures, verbal learning and memory, and executive function. Patients who met criteria for cognitive impairment had, on average, a greater number of adverse SDOH, including lower household incomes and father's education, and higher ADI values compared to those who were cognitively intact. CONCLUSION: We provide new evidence of the role of individual- and community-level SDOH on cognitive outcomes in older adults with epilepsy. This emerging literature highlights the need to examine SDOH beyond epilepsy-related clinical factors. These data could inform the development of interventions focused on increasing access to epilepsy care, education, and resources and promoting brain and cognitive health within the most at-risk communities.

A systematic review of the association between environmental risk factors and the development of irritable bowel syndrome.

BACKGROUND AND AIM: Irritable bowel syndrome (IBS) is a common gastrointestinal disorder with roots in genetic, immune, psychological, and dietary factors. Recently, the potential correlation between environmental exposures, such as air pollution, and IBS has gained attention. This review aimed to systematically examine existing studies on environmental factors associated with IBS, elucidating this interplay and guiding future research. METHODS: A literature search was conducted in Medline, EMBASE, Scopus, and Cochrane databases from database inception to October 10, 2023, using the keywords "Irritable Bowel" or IBS or "Irritable Colon" or "Mucous Colitis" or "Spastic Colitis" or "Spastic Colon" AND "environment* exposure*". Studies were included if they were original, published in English, described defined environmental exposure(s), and had documented diagnosis of IBS. For the purposes of this review, articles reporting physical (e.g. radiation and climate change), biological (e.g. bacteria and viruses), and chemical (e.g. harmful gases) exposures were included while psychological and dietary factors, which have been reviewed in detail elsewhere, are outside of the scope. RESULTS: A total of seven studies focusing on air quality, microbial exposure, and other environmental factors were reviewed. Studies highlighted a potential association between air pollutants and increased IBS incidence. Microbial exposure, post-natural disaster or due to poor sanitation, was linked to IBS development and gut dysbiosis. Other exposures, such as early pet ownership, were also associated with IBS risk. CONCLUSION: Existing research demonstrates an epidemiologic relationship between environmental exposures and the development of IBS. Further research is needed to understand these associations.

Effect of environmental factors on conjugative transfer of antibiotic resistance genes in aquatic settings.

Antimicrobial-resistance genes (ARGs) are spread among bacteria by horizontal gene transfer, however, the effect of environmental factors on the dynamics of the ARG in water environments has not been very well understood. In this systematic review, we employed the regression tree algorithm to identify the environmental factors that facilitate/inhibit the transfer of ARGs via conjugation in planktonic/biofilm-formed bacterial cells based on the results of past relevant research. Escherichia coli strains were the most studied genus for conjugation experiments as donor/recipient in the intra-genera category. Conversely, Pseudomonas spp., Acinetobacter spp., and Salmonella spp. were studied primarily as recipients across inter-genera bacteria. The conjugation efficiency (ce) was found to be highly dependent on the incubation period. Some antibiotics, such as nitrofurantoin (at ≥0.2 µg ml-1) and kanamycin (at ≥9.5 mg l-1) as well as metallic compounds like mercury (II) chloride (HgCl2, ≥3 µmol l-1), and vanadium (III) chloride (VCl3, ≥50 µmol l-1) had enhancing effect on conjugation. The highest ce value (-0.90 log10) was achieved at 15°C-19°C, with linoleic acid concentrations <8 mg l-1, a recognized conjugation inhibitor. Identifying critical environmental factors affecting ARG dissemination in aquatic environments will accelerate strategies to control their proliferation and combat antibiotic resistance.

Changes in microcystin concentration in Lake Taihu, 13 years (2007-2020) after the 2007 drinking water crisis.

Since the 2007 water crisis occurred in Lake Taihu, substantial measures have been taken to restore the lake. This study evaluates the effectiveness of these restoration activities. We examined the physicochemical parameters and the distribution of microcystin and Microcystis in both the water column and sediment during the bloom period of May 2020 to October 2020. The mean value of extracellular and intracellular microcystin content was 0.12 µg L-1 and 16.26 µg L-1, respectively. The mean value of microcystin in sediment was 172.02 ng g-1 and peaked in August. The concentration in the water and sediment was significantly lower than the historical average concentration. The abundance of toxigenic Microcystis and total Microcystis in the water column ranged from 2.61 × 102 to 2.25 × 109 copies·L-1 and 8.28 × 105 to 2.76 × 109 copies·L-1, respectively. The proportion of toxic Microcystis in the sediment ranging from 31.2% to 19.12%. The highest and lowest region was Meiliang Bay and Grass-algae type zone, respectively. The copy number of the 16S rRNA gene was 1-4 orders of magnitude higher than that of mcyA gene in populations of Microcystis, indicating that non-toxic Microcystis was the dominant form in the majority of the lake. The abundance of toxic Microcystis in the water column was positively correlated with total phosphorus, PO43--P and pH, while the water temperature played distinct role to the distribution of toxic Microcystis in sediment. Our research indicated phosphorus remains a key factor influencing the toxic Microcystis and microcystins in the water column. pH played distinct roles in the distribution of microcystins in sediment and water column. The increasing water temperature is a threat. Explicit management actions and policies, which take into account nutrient concentrations, pH, and increasing temperatures, are necessary to understand and control the distribution of microcystin and Microcystis in Lake Taihu.