Prevalence of opportunistic pathogens and anti-microbial resistance in urban aquaculture ponds.

Bacterial antimicrobial resistance (AMR) has emerged as a significant concern worldwide. The microbial community profile and potential AMR level in aquaculture ponds are often undervalued and attract less attention than other aquatic environments. We used amplicon and metagenomic shotgun sequencing to study microbial communities and AMR in six freshwater polyculture ponds in rural and urban areas of Bangladesh. Amplicon sequencing revealed different community structures between rural and urban ponds, with urban ponds having a higher bacterial diversity and opportunistic pathogens including Streptococcus, Staphylococcus, and Corynebacterium. Despite proteobacterial dominance, Firmicutes was the most interactive in the community network, especially in the urban ponds. Metagenomes showed that drug resistance was the most common type of AMR found, while metal resistance was only observed in urban ponds. AMR and metal resistance genes were found mainly in beta and gamma-proteobacteria in urban ponds, while AMR was found primarily in alpha-proteobacteria in rural ponds. We identified potential pathogens with a high profile of AMR and metal resistance in urban aquaculture ponds. As these ponds provide a significant source of protein for humans, our results raise significant concerns for the environmental sustainability of this food source and the dissemination of AMR into the food chain.

Effects of carbon source addition in rearing water on sediment characteristics, growth and health of cultured marron (Cherax cainii).

Carbon sources are considered as critical input for the health and immunity of aquatic animals. The present study investigated the impact of different carbon sources on water quality parameters, carbon to nitrogen (C/N) ratio and microbial community in sediments, and health responses of marron (Cherax cainii) under laboratory conditions. Following one week of acclimation, 120 marron were randomly assigned to 12 experimental tanks. There were four treatments including one untreated control and three groups with carbon addition to maintain a C/N ratio of 12 maintained in culture water. Carbon supplementation groups included corn flour (CBC12), molasses (MBC12) and wheat flour (WBC12). At the end of the 60-day trial, MBC12 resulted in the highest sediment C/N ratio, followed by CBC12. Weight gain and specific growth rate were higher in MBC12, compared to control. The protease activity in marron hepatopancreas, total haemocyte count and lysozyme activity in haemolymph were highest in MBC12. Analysis of 16S rRNA sequence data of tank sediments revealed increased bacterial alpha diversity in MBC12 and WBC12. Proteobacteria was the most abundant phylum in MBC12 (88.6%), followed by control (82.4%) and CBC12 (72.8%). Sphingobium and Novosphingobium were the most abundant genera in control and MBC12 groups, respectively. Higher Aeromonas abundance in CBC12 and Flavobacterium in WBC12 were observed. Overall results indicated that MBC12 led to improved water quality, retaining high C/N ratio and enriched the bacterial populations in sediments resulting in improved growth and immune performance of marron.

Glucose-Responsive Chitosan Nanoparticle/Poly(vinyl alcohol) Hydrogels for Sustained Insulin Release In Vivo.

Stimuli-responsive hydrogels (HGs) with a controlled drug release profile are the current challenge for advanced therapeutic applications. Specifically, antidiabetic drug-loaded glucose-responsive HGs are being investigated for closed-loop insulin delivery in insulin-dependent diabetes patients. In this direction, new design principles must be exploited to create inexpensive, naturally occurring, biocompatible glucose-responsive HG materials for the future. In this work, we developed chitosan nanoparticle/poly(vinyl alcohol) (PVA) hybrid HGs (CPHGs) for controlled insulin delivery for diabetes management. In this design, PVA and chitosan nanoparticles (CNPs) are cross-linked with a glucose-responsive formylphenylboronic acid (FPBA)-based cross-linker in situ. Leveraging the structural diversity of FPBA and its pinacol ester-based cross-linkers, we fabricate six CPHGs (CPHG1-6) with more than 80% water content. Using dynamic rheological measurements, we demonstrate elastic solid-like properties of CPHG1-6, which are dramatically reduced under low-pH and high-glucose environments. An in vitro drug release assay reveals size-dependent glucose-responsive drug release from the CPHGs under physiological conditions. It is important to note that the CPHGs show appreciable self-healing and noncytotoxic properties. Promisingly, we observe a significantly slower insulin release profile from the CPHG matrix in the type-1 diabetes (T1D) rat model. We are actively pursuing scaling up of CPHGs and the in vivo safety studies for clinical trial in the near future.

Heavy metals contamination in sediments of Bharalu river, Guwahati, Assam, India: A tributary of river Brahmaputra.

This study aimed to assess heavy metals in the surface sediments of the Bharalu river, India. Metal concentrations ranged from 6.65-54.6 mg/kg for Ni, 25.2-250.0 mg/kg for Zn, 83.3-139.1 mg/kg for Pb, and 11940.0-31250.0 mg/kg for Fe. The level of metal contamination was assessed using sediment quality guidelines, geo-accumulation index (Igeo), enrichment factor (EF), pollution Load Index (PLI),Nemerow's pollution index (PIN), and potential ecological risk index. Pb exceeded the sediment quality guidelines at all sites indicating a potential threat to the river ecosystem. (Igeo) and EF also showed moderate to severe enrichment for Pb. Potential ecological risk (RI) showed low risk in the sediments, and Pb is the major contributor to ecological risk. Overall, pollution indices revealed comparably higher contamination of the sediments in the downstream sites than in the upstream site. PCA and correlation matrix analysis indicated both anthropogenic and natural origins for metals. Among anthropogenic sources, urban discharges and waste dumping could be mainly attributed to metal contamination in the river sediments. These findings may aid in developing future river management methods explicitly aimed at tackling heavy metal pollution to prevent further damage to the river ecosystem.

The Legal Void Outside Brain Death in India: The Legislative Need of 'DNR' in Brain Death.

Objective: The legal definitions of brain death are tantamount for legal dogmas and sometimes criminal intimidation of the treating doctors. The tests for brain death are only applicable to patients planned for organ transplantation. We intend to discuss the necessity of the "Do Not Resuscitate (DNR)" legislature in cases of brain death patients and applicability of tests for brain death irrespective of the intention for organ donation. Methods: A comprehensive review of the literature was performed till May 31, 2020 from the MEDLINE (1966 to July 2019) and Web of Science (1900 to July 2019). Search criteria included all publications with the MESH terms: "Brain Death/legislation and jurisprudence"[Mesh] OR "Brain Death/organization and administration"[Mesh] AND "India" [Mesh]. We also discuss the different opinions and implications of brain death versus brain stem death in India with the senior author (KG) who was responsible for South Asia's first multi-organ transplant after certifying brain death. Additionally, a hypothetical scenario of a DNR case is discussed in the current legal paradigm of India. Results: The systematic search yielded only five articles reporting a series of brain stem death cases with an acceptance rate of organ transplant among brain stem deaths being 34.8%. The most common solid organs transplanted were the kidney (73%) and liver (21%). A hypothetical scenario of a DNR and possible legal implications of the same under the current 'Transplantation of Human Organs Act (THOA)' of India remains unclear. A comparison of brain death laws in most Asian countries shows a similar pattern regarding the declaration of brain death and the lack of knowledge or legislature regarding DNR cases. Conclusion: After the determination of brain death, discontinuation of organ support requires the consent of the family. The lack of education and the lack of awareness have been major impediments in this medico-legal battle. There is also an urgent need to make laws for cases that do not qualify for brain death. This would help in not only realistic realization but also better triage of the health care resources while legally safeguarding the medical fraternity.

Dietary selenium levels modulates antioxidant, cytokine and immune response and selenoproteins mRNA expression in rats under heat stress condition.

BACKGROUND: Higher environmental temperature is a major abiotic stress factor for animals and human beings. The selenium (Se) is an important trace mineral having diverse health promoting effects under stress conditions. However, studies on dietary requirement of selenium under prolonged heat stress condition are lacking. Present study discern the effect of higher dietary Se levels on antioxidant, cytokine, haemato-biochemical profile, and immune response, and the selenoproteins mRNA expression in rats under prolonged heat stress (HS) condition. METHODS: Weaned Wistar rats (4 wk age; 67.6 ± 1.53 g BW; n = 72) housed under thermoneutral (TN) or HS conditions and fed with purified diets containing three graded Se levels were divided in six experimental groups. The groups were 1) TN control with 138 ppb Se (TN_CON), 2) HS control with 138 ppb Se (HS_CON), 3) TN with higher Se @ 291 ppb (TN_Se1), 4) HS with higher Se @ 291 ppb (HS_Se1) 5) TN with higher Se @ 460 ppb (TN_Se2), 6) HS with higher Se @ 460 ppb (HS_Se2). Rats in all the six groups were maintained in TN environmental conditions (57.3 ± 0.22 temperature humidity index; THI) for initial 28 days period. Subsequently, rats of HS groups were exposed to 77.0 ± 0.11 THI for 6 h/d in a psychrometric chamber for last fourteen days. RESULTS: Higher dietary Se (291 and 460 ppb) significantly improved the blood hemoglobin concentration and reduced serum alanine aminotransferase activity of rats under HS conditions. The serum triiodothyronine and insulin levels were significantly higher in high dietary Se groups irrespective of the environmental conditions. Similarly, the serum reduced glutathione levels, and catalase and superoxide dismutase enzyme activity were increased and malondialdehyde levels were reduced in high dietary Se groups irrespective of stress conditions. The glutathione peroxidase (GPx) activity was significantly higher in 460 ppb dietary Se groups as compared to other groups. The serum pro-inflammatory cytokine interleukin (IL)- 1 was declined, whereas the anti-inflammatory cytokine IL-10 level was increased in high dietary Se fed rats under both HS and TN conditions with 460 ppb dietary Se groups showing pronounced effects. Further, there was heat stress- and dietary Se level dependent- up regulation in hepatic GPx and iodothyronine deiodinase-II mRNA expression and similar pattern was noticed in hepatic thioredoxin reductase mRNA expression. The selenoprotein-P mRNA expression was up regulated in 460 ppb Se fed HS group as compared to CON and Se1_C groups. High dietary Se improved the humoral immune response 7d after antigen inoculation under HS conditions whereas cell-mediated immune response was augmented in rats fed higher Se under TN condition. CONCLUSION: It is concluded that under prolonged heat stress conditions the dietary requirement of Se may be increased to 460 ppb for improving the antioxidant status and humoral immune response, cytokine levels, modulating the thyroid and insulin hormone, and the selenoproteins mRNA expression of rats.

Study of Allergen Patterns in Cases of Moderate to Severe Persistent Allergic Rhinitis in Central India.

The prevalence of Allergic rhinitis (AR) is associated with a variety of environmental allergens and the level of exposure is through inhalation, or ingestion. It is clear from several studies and guidelines that screening and identification of various allergens in a particular region can facilitate in diagnosing, treating and formulating preventive strategies against AR. To study the allergen patterns in patients with Moderate to severe persistent allergic rhinitis from Central India. Male/female of 6 to 63 years age group, presenting with itching of the nose, sneezing, rhinorrhoea, nasal congestion and nasal obstruction. Patients suffering from infective pathology of nose and sinuses. The study group comprised of 1350 male/female of the age group between 6 and 63 years. Modified skin prick test was performed according to the method of Pepys and Bernstein. The ratio of allergen wheal and histamine wheal was used to evaluate the results. The reactions with wheal diameter 3 mm or greater than the reading in the negative control were considered as positive reaction. Results of the study indicate that in Central India, the common allergens are pollens (78.5%), insects (64.5%), dust (38.5%), dust mites (18%) and food (10%) causing moderate to severe persistent allergic rhinitis. The study provided an insight and identified the allergen pattern in Central India. The results were of great help in counseling for avoidance therapy and for deciding allergen specific immunotherapy which is the standard treatment protocol to modify natural course of allergic rhinitis at this point of time.

Heavy metal contamination in the complete stretch of Yamuna river: A fuzzy logic approach for comprehensive health risk assessment.

River Yamuna is one of the most sacred major tributaries of river Ganga. This study aimed to assess the level of heavy metals in monsoon and non-monsoon season in river Yamuna in Uttar Pradesh, India and to assess the possible source of contamination and its associated health risk. Except for iron (Fe), the mean levels of all metals were within drinking water safe limits in both seasons. Except for chromium (Cr), lower values were observed for other metals in the monsoon season could be attributed dilution effect. Multivariate analysis indicated that both geogenic and anthropogenic sources contribute to heavy metals in river Yamuna in monsoon and non-monsoon seasons. The health risk in terms of hazard index (HI) and fuzzy-logic hazard index (FHI) demonstrated that both HI and FHI values among children exceeded the safe limit in most of the sites in non-monsoon seasons and in few in monsoon season. For adults, HI and FHI values were within safe limit.

Qualitative comparison of elemental concentration in soils and other geomaterials using FP-XRF.

Field portable X-ray fluorescence (FP-XRF) has tremendous potential in geoenvironmental engineering as a qualitative assessment tool. Identification of the elevated concentrations of the selected elements (Cr, Cu, Mn, Ni, Pb, and Zn) in various geomaterials like soil-like-material (SLM), incinerated bottom ash (IBA), construction and demolition waste (CDW), zinc tailings (ZT) and fly ash (FA) was performed by FP-XRF and compared with the local soil-Delhi silt. Comparably higher concentrations (mg/kg) of Cr (401.0), Cu (499.0), Pb (532.0), Zn (608.0) in SLM, Cr (195.0), Cu (419.0), Ni (93.0), Pb (931.0), Zn (771.0) in IBA and Cr (195.0), Cu (4000.0), Pb (671.0), Zn (7122.0) in ZT were observed. CDW and FA showed similar concentrations range as in local soils. FP-XRF was also used in-situ on local soil at 11 sites to examine its ability to identify the elements with significant variations in concentrations. The results showed high variability in Cl and S concentration values across the 11 sites attributed to the changing moisture content and dissolved salts. The concentration range for the remaining elements were similar at all sites. The verification of the detected elements through visual inspection of the spectrum was also carried out.

Sources of protein diet differentially stimulate the gut and water microbiota under freshwater crayfish, marron (Cherax cainii, Austin 2002) culture.

To reduce the reliance on fishmeal (FM), other protein sources have been evaluated on cultured animals. In a 60-days feeding trial, marrons (Cherax cainii) were fed a FM diet and five test diets containing 100% of plant-based protein sources such as soybean, lupin and valorised animal-based proteins such as poultry-by-product, black soldier fly and tuna hydrolysate. At the end of the trial, DNA samples from marron gut and rearing water were investigated through DNA-based 16S rRNA gene sequencing. Plant-based diets increased abundance for Aeromonas, Flavobacterium and Vogesella, whereas animal and insect proteins influenced diverse bacterial groups in the gut linked to various metabolic activities. Insect meal in the water favoured the growth of Firmicutes and lactic acid bacteria, beneficial for the marron health. Aeromonas richness in the gut and reared water signified the ubiquitous nature of the genus in the environment. The higher bacterial diversity in the gut and water with PBP and BSF was further supported by qPCR quantification of the bacterial single-copy gene, rpoB. The overall results suggested that PBP and BSF can exhibit positive and influential effects on the gut and water microbial communities, hence can be used as sustainable ingredients for the crayfish aquaculture.

A global perspective of the current state of heavy metal contamination in road dust.

Heavy metals are persistent and bio-accumulative, and pose potential risk to human health and ecosystem. We reviewed the current state of heavy metal contamination, the ecotoxicological and human health risk of heavy metals reported in urban road dust from various cities in different continents (Asia, Europe, Africa, America, and Australia). We compared and synthesized the findings on the methods related to sample collection, extraction, analytical tools of heavy metals, their concentrations, level of contamination, ecological risk, non-carcinogenic risk, and carcinogenic risk in road dust. Concentrations of Pb, Zn, Cu, Ni, Cd, Cr, Mn, and Fe were found to be higher than their background values in soil. As expected, the contamination levels of the heavy metals varied extensively among cities, countries, continents, and periods. A high level of contamination is observed for Pb and Cd in road dust due to operating leaded gasoline and the old vehicle population. The highest Zn contamination was observed from road dust in Europe, followed by Asia, Africa, Australia, and America (North America and South America). Cu contamination and the pollution load index (PLI) is found to be the highest in Europe and lowest in Africa, with in-between values of PLI in American and African cities. The potential ecological risk on different continents was observed highest in Asia, followed by Europe, Australia, America, and Africa. A comparative assessment of non-carcinogenic risk for children indicated that Australia is the most susceptible country due to high heavy metal exposure in road dust, followed by Asia. However, there is no susceptible risk in European, African, and American cities. We did not observe any potential risk to adults due to non-carcinogenic metals. Carcinogenic risk to all age groups was within the threshold limit range for all the regions worldwide.

Hyponatremia in Patients Admitted to Intensive Care Unit of a Tertiary Center: A Descriptive Cross-sectional Study.

Introduction: Hyponatremia is one of the common electrolyte abnormalities in intensive care unit settings. Hyponatremia may lead to an increased hospital stay, morbidity and mortality. Hyponatremia can occur due to a variety of iatrogenic as well as part of complex disease processes during hospital admission. The objective of this study was to find the prevalence of hyponatremia in patients admitted to the intensive care unit of a tertiary care centre. Methods: A descriptive cross-sectional study was conducted in the intensive care unit of a tertiary care centre for a duration of six months from 12 August 2015 to 11 January 2016. Ethical approval was taken from the Institutional Review Committee (Reference number: 124/6-11-E/072/073). Data was collected from hospital records. Patients with abnormal serum sodium levels after admission to the intensive care unit were included in the study. Hyponatremia was defined as a serum sodium level less than 135 mEq/L. Convenience sampling methods were used. Point estimate and 95% Confidence Interval were calculated. Results: Among 102 patients, the prevalence of hyponatremia was found to be 21 (20.59%) (12.74-28.44, 95% Confidence Interval). Conclusions: The prevalence of hyponatremia in patients admitted to the intensive care unit was higher than in other studies conducted in similar settings. Keywords: cross-sectional study; prevalence; sodium.

Evaluation of cell wall-associated direct extracellular electron transfer in thermophilic Geobacillus sp.

In this study, a cell wall-associated extracellular electron transfer (EET) was determined in the thermophilic Geobacillus sp. to utilize iron as a terminal electron acceptor. The direct extracellular transfer of its electrons was primarily linked to the cell wall cytochrome-c and diffusible redox mediators like flavins during the anoxic condition. Based on the azo dye decolouration and protein film voltammetry, it was revealed that, in the absence of surface polysaccharide and diffusible mediators, the cell wall-associated EET pathway was likely to be a favorable mechanism in Geobacillus sp. Since the permeability of such redox molecule is primarily limited to the cell wall, the electron transfer occurs by direct contact with cell wall-associated cytochrome and final electron acceptor. Furthermore, transfer of electrons with the help of redox shuttling molecules like riboflavin from cytochrome to cells, vice versa indicates that Geoabcillus sp. has adopted this unique pathway during an anoxic environment for its respiration. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02917-2.

Metal determination and biochemical status of marine fishes facilitate the biomonitoring of marine pollution.

In the present study, the bioaccumulation of chromium, manganese, cobalt, copper, zinc, selenium, arsenic, strontium, cadmium, tin, antimony and lead in tissues of thirty marine fish species collected from New Ferry Whorf, Sassoon dock and Versova fishing harbour in Mumbai, India, were analysed. The bioaccumulation patterns of these twelve elements were determined to assess pollution biomarkers based on cellular and oxidative stresses. Catalase, superoxide dismutase and glutathione-s-transferase, glycolytic enzymes viz. lactate dehydrogenase and malate dehydrogenase, protein metabolism enzymes viz. aspartate transferase and alanine transferase, and lipid peroxidation were significantly higher in muscle and gill tissues. The activities of the neurotransmitter enzyme acetylcholine esterase in muscle and brain tissues was inhibited due to pollution. This study suggested that biochemical attributes such as oxidative stress enzymes, cellular biomarkers, neurotransmitter enzymes and metal and metalloid contamination could be successfully employed, even at low concentrations, as reliable biomarkers for biomonitoring of contaminated marine ecosystems.

Improving the feasibility of aquaculture feed by using microalgae.

The aquaculture industry is an efficient edible protein producer and grows faster than any other food sector. Therefore, it requires enormous amounts of fish feed. Fish feed directly affects the quality of produced fish, potential health benefits, and cost. Fish meal (FM), fis oil (FO), and plant-based supplements, predominantly used in fish feed, face challenges of low availability, low nutritional value, and high cost. The cost associated with aquaculture feed represents 40-75% of aquaculture production cost and one of the key market drivers for the thriving aquaculture industry. Microalgae are a primary producer in aquatic food chains. Microalgae are expanding continuously in renewable energy, pharmaceutical pigment, wastewater treatment, food, and feed industries. Major components of microalgal biomass are proteins with essential amino acids, lipids with polyunsaturated fatty acids (PUFA), carbohydrates, pigments, and other bioactive compounds. Thus, microalgae can be used as an essential, viable, and alternative feed ingredient in aquaculture feed. In recent times, live algae culture, whole algae, and lipid-extracted algae (LEA) have been tested in fish feed for growth, physiological activity, and nutritional value. The present review discusses the potential application of microalgae in aquaculture feed, its mode of application, nutritional value, and possible replacement of conventional feed ingredients, and disadvantages of plant-based feed. The review also focuses on integrated processes such as algae cultivation in aquaculture wastewater, aquaponics systems, challenges, and future prospects of using microalgae in the aquafeed industry.

Chemical source profiles of fine particles for five different sources in Delhi.

Increasing emissions from sources such as construction and burning of biomass from crop residues, roadside and municipal solid waste have led to a rapid increase in the atmospheric concentrations of fine particulate matter (≤2.5 µm; PM2.5) over many Indian cities. Analyses of their chemical profiles are important for receptor models to accurately estimate the contributions from different sources. We have developed chemical source profiles for five important pollutant sources - construction (CON), paved road dust (PRD), roadside biomass burning (RBB), solid waste burning (SWB), and crop residue burning (CPB) - during three intensive campaigns (winter, summer and post-monsoon) in and around Delhi. We obtained chemical characterisations of source profiles incorporating carbonaceous material such as organic carbon (OC) and elemental carbon (EC), water-soluble ions (F-, Cl-, NO2-, NO3-, SO42-, PO43-, Na+ and NH4+), and elements (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br, Rb, Sr, Ba, and Pb). CON was dominated by the most abundant elements, K, Si, Fe, Al, and Ca. PRD was also dominated by crustal elements, accounting for 91% of the total analysed elements. RBB, SWB and CPB profiles were dominated by organic matter, which accounted for 94%, 86.2% and 86% of the total PM2.5, respectively. The database of PM emission profiles developed from the sources investigated can be used to assist source apportionment studies for accurate quantification of the causes of air pollution and hence assist governmental bodies in formulating relevant countermeasures.

All India AYUSH post graduate entrance exam 2019 - AYURVEDA MCQ item analysis.

BACKGROUND: AIAPGET 2019, an all India ranking entrance Test for MD/MS courses of Ayurveda, Unani, Siddha and Homeopathy stream was conducted by joint collaboration of National Testing Agency (NTA) and All India Institute of Ayurveda (AIIA). In this article, we present the item analysis of AIAPGET 2019 Ayurveda stream MCQs. OBJECTIVES: The aim of this article was to analyse the MCQs of AIAPGET 2019 of Ayurveda stream. MATERIALS AND METHODS: This exam was computer based conducted all over 25 centers across India. The question paper had 100 MCQs with 1 correct answer and 3 distractors for each item (Problem statement). RESULTS: AIAPGET 2019 question paper of Ayurveda stream had a Difficulty index of 37.32 ± 16.11 Discriminatory Index of 0.46 ± 0.27 and Distractor Index of 89 ± 17.8. CONCLUSION: Our analysis showed that though ideal, the question paper trended towards difficulty side.

The Effect of Two Dietary Protein Sources on Water Quality and the Aquatic Microbial Communities in Marron (Cherax cainii) Culture.

Feeding freshwater crayfish species with different diets not only affects the water quality but also induces the abundance of various microbial communities in their digestive tracts. In this context, very limited research has been undertaken to understand the impacts of various protein incorporated aqua-diets on the characteristics of water and its microbial communities. In this study, we have critically analysed the water quality parameters including pH, dissolved oxygen, nitrate, nitrite, ammonia and phosphorus, as well as bacterial communities under marron (Cherax cainii) aquaculture, fed fishmeal (FM) and poultry by-product meal (PBM)-based diets for 60 days. The results unveiled that over the time, feeding has significant impacts on organic waste accumulation, especially ammonia, nitrate, nitrite and phosphate, while no effects were observed on pH and dissolved oxygen. Analysis of 16S rRNA sequence data of water sample indicated significant (P < 0.05) shift of microbial abundance in post-fed FM and PBM water with the evidence of microbial transmission from the gut of marron. Post-fed marron resulted in a significant correlation of Hafnia, Enterobacter, Candidatus Bacilloplasma and Aquitella with the quality and microbial population of water. The results of this study generated valuable knowledge database of microbes-water relationship for better health management practices and production of marron aquaculture fed with FM and PBM diets in under restricted feeding regime with the feeding ratios provided.

Heavy metal(loid)s contamination and health risk assessment of soil-rice system in rural and peri-urban areas of lower brahmaputra valley, northeast India.

The soil-rice system in rural and peri-urban areas of the lower Brahmaputra valley, northeast India was investigated for heavy metal(loid)s using Nemerow's pollution index (PIN) and potential ecological risk index (RI). Potential health risk due to rice consumption grown in the region was assessed in terms of carcinogenic and non-carcinogenic risks. Around 95% of the soil showed acidic nature that ranged from weakly acidic to strongly acidic soil. In terms of PIN, 27.3% of the sampling sites were heavily polluted (PIN≥3), 34.8% moderately, and 37.9% were slightly polluted. The Pb concentration was comparably higher in 57.1% of the rice grain samples and the mean As level (0.17 mg kg-1) was close to the WHO limit. The non-carcinogenic risk in terms of hazard quotient (HQ) was high primarily due to As (HQ > 1), whereas other metals had limited contribution (HQ < 1). The carcinogenic risk based on total cancer risk (TCR) values for adults and children ranged between 0.0039 - 0.019 and 0.0043-0.0211, respectively, exceeding the maximum acceptable level of 1 × 10-4. Among the rice varieties, for non-carcinogenic risks, the maximum hazard index (HI) was noticed for Bahadur and the minimum for Ranjit. Whereas for carcinogenic risks, the maximum TCR was observed for Mahsuri and the minimum for Moynagiri.

Mitigation potential of selenium nanoparticles and riboflavin against arsenic and elevated temperature stress in Pangasianodon hypophthalmus.

Climate change impact has disturbed the rainfall pattern worsening the problems of water availability in the aquatic ecosystem of India and other parts of the world. Arsenic pollution, mainly through excessive use of groundwater and other anthropogenic activities, is aggravating in many parts of the world, particularly in South Asia. We evaluated the efficacy of selenium nanoparticles (Se-NPs) and riboflavin (RF) to ameliorate the adverse impacts of elevated temperature and arsenic pollution on growth, anti-oxidative status and immuno-modulation in Pangasianodon hypophthalmus. Se-NPs were synthesized using fish gill employing green synthesis method. Four diets i.e., Se-NPs (0 mg kg-1) + RF (0 mg kg-1); Se-NPs (0.5 mg kg-1) + RF (5 mg kg-1); Se-NPs (0.5 mg kg-1) + RF (10 mg kg-1); and Se-NPs (0.5 mg kg-1) + RF (15 mg kg-1) were given in triplicate in a completely randomized block design. The fish were treated in arsenic (1/10th of LC50, 2.68 mg L-1) and high temperature (34 °C). Supplementation of the Se-NPs and RF in the diets significantly (p < 0.01) enhanced growth performance (weight gain, feed efficiency ratio, protein efficiency ratio, and specific growth rate), anti-oxidative status and immunity of the fish. Nitroblue tetrazolium (NBT), total immunoglobulin, myeloperoxidase and globulin enhanced (p < 0.01) with supplementation (Se-NPs + RF) whereas, albumin and albumin globulin (A:G) ratio (p < 0.01) reduced. Stress biomarkers such as lipid peroxidation in the liver, gill and kidney, blood glucose, heat shock protein 70 in gill and liver as well as serum cortisol reduced (p < 0.01) with supplementation of Se-NPs and RF, whereas, acetylcholine esterase and vitamin C level in both brain and muscle significantly enhanced (p < 0.01) in compared to control and stressors group (As + T) fed with control diet. The fish were treated with pathogenic bacteria after 90 days of experimental trial to observe cumulative mortality and relative survival for a week. The arsenic concentration in experimental water and bioaccumulation in fish tissues was also determined, which indicated that supplementation of Se-NPs and RF significantly reduced (p < 0.01) bioaccumulation. The study concluded that a combination of Se-NPs and RF has the potential to mitigate the stresses of high temperature and As pollution in P. hypophthalmus.