Metagenomic and culture-dependent approaches unveil active microbial community and novel functional genes involved in arsenic mobilization and detoxification in groundwater.

BACKGROUND: Arsenic (As) and its species are major pollutants in ecological bodied including groundwater in Bangladesh rendering serious public health concern. Bacteria with arsenotrophic genes have been found in the aquifer, converting toxic arsenite [As (III)] to less toxic arsenate [As (V)] that is easily removed using chemical and biological trappers. In this study, genomic and metagenomic approaches parallel to culture-based assay (Graphical abstract) have made it possible to decipher phylogenetic diversity of groundwater arsenotrophic microbiomes along with elucidation of their genetic determinants. RESULTS: Seventy-two isolates were retrieved from six As-contaminated (average As concentration of 0.23 mg/L) groundwater samples from Munshiganj and Chandpur districts of Bangladesh. Twenty-three isolates harbored arsenite efflux pump (arsB) gene with high abundance, and ten isolates possessing arsenite oxidase (aioA) gene, with a wide range of minimum inhibitory concentration, MICAs (2 to 32 mM), confirming their role in arsenite metabolism. There was considerable heterogeneity in species richness and microbial community structure. Microbial taxa from Proteobacteria, Firmicutes and Acidobacteria dominated these diversities. Through these combinatorial approaches, we have identified potential candidates such as, Pseudomonas, Acinetobacter, Stenotrophomonas, Achromobacter, Paraburkholderia, Comamonas and Klebsiella and associated functional genes (arsB, acr3, arsD, arsH, arsR) that could significantly contribute to arsenite detoxification, accumulation, and immobilization. CONCLUSIONS: Culture-dependent and -independent shotgun metagenomic investigation elucidated arsenotrophic microbiomes and their functions in As biogeochemical transformation. These findings laid a foundation for further large-scale researches on the arsenotrophic microbiomes and their concurrent functions in As biogeochemical transformation in As-contaminated areas of Bangladesh and beyond.

Genomic and evolutionary study from SARS-CoV-2 virus isolates from Bangladesh during the early stage of pandemic strongly correlate with European origin and not with China.

The goal of this study was to identify the genomic variants and determine molecular epidemiology of SARS-CoV-2 virus during the early pandemic stage in Bangladesh. Viral RNA was extracted, converted to cDNA, and amplified using Ion AmpliSeq™ SARS-CoV-2 Research Panel. 413 unique mutants from 151 viral isolates were identified. 80% of cases belongs to 8 mutants: 241C toT, 1163A toT, 3037C toT, 14408C toT, 23403A toG, 28881G toA, 28,882 G toA, and 28883G toC. Observed dominance of GR clade variants that have strong presence in Europe, suggesting European channel a possible entry route. Among 37 genomic mutants significantly associated with clinical symptoms, 3916CtoT (associated with sore-throat), 14408C to T (associated with cough-protection), 28881G to A, 28882G to A, and 28883G to C (associated with chest pain) were notable. These findings may inform future research platforms for disease management and epidemiological study.

Incredible affinity of Kattosh with PPAR-γ receptors attenuates STZ-induced pancreas and kidney lesions evidenced in chemicobiological interactions.

Since ancient times, plants have been used as green bioresources to ensure a healthier life by recovering from different diseases. Kattosh (Lasia spinosa L. Thwaites) is a local plant with various traditional uses, especially for arthritis, constipation and coughs. This research investigated the effect of Kattosh stem extract (LSES) on streptozotocin-induced damage to the pancreas, kidney, and liver using in vitro, in vivo and in silico methods. In vitro phytochemical, antioxidative and anti-inflammatory effects of LSES were accomplished by established methods followed by antidiabetic actions in in vivo randomized controlled intervention in STZ-induced animal models for four weeks. In an in silico study, LSES phytocompounds interacted with antidiabetic receptors of peroxisome proliferator-activated receptor-gamma (PPAR, PDB ID: 3G9E), AMP-activated protein kinase (AMPK, PDB ID: 4CFH) and α-amylase enzyme (PDB ID: 1PPI) to verify the in vivo results. In addition, LSES showed promising in vitro antioxidative and anti-inflammatory effects. In contrast, it showed a decrease in weekly blood glucose level, normalized lipid profile, ameliorated liver and cardiac markers, managed serum AST and ALT levels, and increased glucose tolerance ability in the animal model study. Restoration of pancreatic and kidney damage was reflected by improving histopathological images. In ligand-receptor interaction, ethyl α-d-glucopyranoside of Kattosh showed the highest affinity for the α-amylase enzyme, PPAR, and AMPK receptors. Results demonstrate that the affinity of Kattosh phytocompounds potentially attenuates pancreatic and kidney lesions and could be approached as an alternative antidiabetic source with further clarification.

Study of thyroid function among COVID-19-affected and non-affected people during pre and post-vaccination.

The novel coronavirus COVID-19 has caused a global pandemic with many long-ranging effects on the physiological balance of the human body. The impact of COVID-19 on the thyroid axis remains uncertain. Our aim was to assess the long-term consequences of COVID-19 infection and its vaccination with thyroid hormones. Thirty laboratory-confirmed COVID-19-positive patients with no vaccination record, thirty COVID-19-negative patients with vaccination records, and ten healthy subjects were retrospectively, and cross-sectionally enrolled in this study. An ELISA assay was performed to evaluate thyroid function tests, including the total triiodothyronine (TT3), total thyroxine (TT4), and thyroid stimulating hormone (TSH). We found decreased levels of TT3, average or low plasma T4 levels, and standard or slightly decreased TSH levels in unvaccinated COVID-19-positive patients than in the healthy group, while the vaccinated COVID-19-negative group had normal thyroid hormone levels compared to controls. The correlation between TT3 and TSH levels gradually shifted from no association to a negative pattern in the unvaccinated COVID-19-positive group. Again, a highly significant negative correlation between TSH and TT3 was observed on days above 150, although a slight fluctuation was noted on day 90. This pilot study from Bangladesh shows that abnormalities in thyroid function can be observed during COVID-19 infection and after vaccination, which gradually recovers over time.

Efficacy of Phytochemicals Derived from Avicennia officinalis for the Management of COVID-19: A Combined In Silico and Biochemical Study.

The recent coronavirus disease 2019 (COVID-19) pandemic is a global threat for healthcare management and the economic system, and effective treatments against the pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus responsible for this disease have not yet progressed beyond the developmental phases. As drug refinement and vaccine progression require enormously broad investments of time, alternative strategies are urgently needed. In this study, we examined phytochemicals extracted from Avicennia officinalis and evaluated their potential effects against the main protease of SARS-CoV-2. The antioxidant activities of A. officinalis leaf and fruit extracts at 150 µg/mL were 95.97% and 92.48%, respectively. Furthermore, both extracts displayed low cytotoxicity levels against Artemia salina. The gas chromatography-mass spectroscopy analysis confirmed the identifies of 75 phytochemicals from both extracts, and four potent compounds, triacontane, hexacosane, methyl linoleate, and methyl palminoleate, had binding free energy values of -6.75, -6.7, -6.3, and -6.3 Kcal/mol, respectively, in complexes with the SARS-CoV-2 main protease. The active residues Cys145, Met165, Glu166, Gln189, and Arg188 in the main protease formed non-bonded interactions with the screened compounds. The root-mean-square difference (RMSD), root-mean-square fluctuations (RMSF), radius of gyration (Rg), solvent-accessible surface area (SASA), and hydrogen bond data from a molecular dynamics simulation study confirmed the docked complexes' binding rigidity in the atomistic simulated environment. However, this study's findings require in vitro and in vivo validation to ensure the possible inhibitory effects and pharmacological efficacy of the identified compounds.

Core-shell drug carrier from folate conjugated chitosan obtained from prawn shell for targeted doxorubicin delivery.

A multifunctional drug carrier with dual targeting (magnetic and folate-receptor) and pH sensitive core-shell hybrid nanomaterial has been developed to carry an anticancer drug doxorubicin.Superparamagnetic iron oxide nanoparticles (IONPs) were used as core of the carrier and cross-linked folate conjugated chitosan (FA-CS) was acted as shell in which doxorubicin was physically entrapped. Transmission electron microscopy (TEM) analysis confirmed the average particle size of IONPs and FA-CS coated IONPs 8.2 and 15.4 nm respectively. Magnetic measurement indicated that both the IONPs and FA-CS coated IONPs were superparamagnetic at room temperature with a magnetization value 57.72 and 37.44 emu/g respectively. At pH 5.8 (malignant tissue) showed a burst release of 30.05% of the doxorubicin in the first 4 h followed by a sustained release of 88.26% of drug over 72 h. From these results it is expected that doxorubicin loaded nanoparticles can be a promising drug carrier for the treatment of solid tumors with the ability to reduce toxic side effects of drugs by selective targeting and sustained release.

Development and validation of a non-invasive method for quantifying amino acids in human saliva.

As an analytical matrix, saliva has superior characteristics than blood and urine. Saliva collection is, first and foremost, non-invasive, making it convenient, painless, and secure for more susceptible people. Second, it does not need professional training for medical personnel, resulting in cost-effectiveness and suitability for extensive collection in support of research. In this study, we developed a method and used it to quantify 13 salivary-free amino acid (SFAA) profiles to support the early clinical diagnosis of diseases using LC-MS/MS. Using an Intrada Amino Acid column (100 × 3 mm, 3 µm), chromatographic separation was accomplished with a binary gradient elution, and an electrospray ionisation source running in the positive ionisation mode was chosen for data collection using the multiple reaction monitoring (MRM) modes. Amino acids were extracted from saliva using acetonitrile. In the MRM mode, LODs and LOQs for ten amino acids were in the range of 0.06-2.50 µM and 0.19-7.58 µM, respectively, and those values were in the range of 1.00-3.00 µM and 3.00-8.50 µM, respectively, for three amino acids. Matrix-matched six-point calibration curves showed a linear correlation coefficient (r 2) of ≥0.998. Recovery experiments validated the method by spiking the control sample at three different concentration levels (5, 50 and 100 µM), and the accuracy level was 85-110%. Except for Thr and Ser, intra- (n = 3) and inter-day (n = 3) precision fell between 0.02 and 7.28. Salivary amino acids can serve as possible biomarkers for various malignancies, with fluctuations in body fluids being crucial for cancer diagnosis; therefore, examining amino acid patterns in saliva can assist in early cancer detection. LC-MS offers improved selectivity and sensitivity for non-derivatised amino acid analysis, surpassing conventional methods and offering proactive quality assurance, making it suitable for complicated sample matrices. These discoveries could be significant in investigating new pathways and cancer treatments and looking for possible AA biomarkers for other malignancies and diseases.

Stability, homogeneity and measurement uncertainty estimation of PVP-I solutions for the application on oro and nasopharynx against SARS-CoV-2.

Aqueous solution containing different concentration (0.5, 0.6 and 1.0%) (w/v) of Polyvinyl pyrrolodon-Iodine (PVP-I) complex, a well-known antiseptic; is prepared and the stability and homogeneity of these solution is assessed as per the ICH Guidelines and International Harmonized Protocol respectively. The solutions were found to be sufficiently homogeneous and stable for a year at 25 °C (60%RH). Measurement uncertainty of the prepared PVP-I solutions were estimated by identifying possible sources of uncertainty using Ishikawa diagram and preparing uncertainty budget based on scope of calibration laboratory. The stable and homogenized PVP-I solution is to be used in a clinical trial for the application on oro and nasopharynx against novel SARS-CoV-2 Virus.

Isolation, characterization and pharmacological potentials of methanol extract of Cassia fistula leaves: Evidenced from mice model along with molecular docking analysis.

The purpose of the current investigation was to conduct a detailed analysis of the chemical components and medicinal properties of the methanolic crude extract derived from the leaves of Cassia fistula. This analysis was carried out using both experimental (in vivo) and computational (in silico) methods. Eleven chemicals were chromatographically isolated using GC-MS/MS, which utilizes a library of NIST and Wiley 2020 versions. FTIR analysis of the extract was performed to identify the functional group of the compounds. The glucose-lowering capacity, analgesic, and anti-diarrheal activities of methanolic crude extract were analyzed utilizing a well-known oral glucose tolerance test, tail immersion method, writhing assay, and castor oil-induced diarrheal mice methods, respectively. After 60 min, 120 min, and 180 min of loading the drugs, a significant reduction of blood glucose levels was examined (p < 0.05) in all the extracts of this plant (200 mg/kg, 400 mg/kg and 600 mg/kg) utilized in this research at a time-dependent manner. Similarly, all the crude extracts showed significant (p < 0.05) effects against pain centrally and peripherally compared to the standard drug morphine (2 mg/kg bw) and diclofenac sodium (50 mg/kg bw). Moreover, the methanol extract (400 mg/kg bw) manifested anti-diarrheal efficacy by inhibiting 72.0 % of the diarrheal episode in mice compared to the standard drug loperamide (inhibition = 80.0%). The results of the computational investigations corroborated existing in-vivo findings. Greater or close to equivalent binding affinity to the active binding sites of kappa opioid receptor, glucose transporter 3 (GLUT 3), and cyclooxygenase 2 was indicative of the potential anti-diarrheal, hypoglycemic, and analgesic characteristics of the isolated compounds (COX-2). Moreover, anticancer and antimicrobial potentiality was also found impressive through evaluation of binding affinity with epidermal growth factor receptor (EGFR) and dihydrofolate reductase (DHFR) receptors. Results from this study indicated that C. fistula might be a beneficial natural resource for treating diarrhea, hyperglycemia, and pain. However, additional research is required to conduct a comprehensive phytochemical screening and establish precise action mechanisms of the crude extract or the plant-derived compounds.

Phyto-pharmacological and computational profiling of Bombax ceiba Linn. Leaves revealed pharmacological properties against oxidation, hyperglycemia, pain, and diarrhea.

The present study aimed to conduct phytochemical and pharmacological profiling of methanolic crude extract of leaves of Bombax ceiba Linn. via experimental and computational approaches. Six secondary metabolites were isolated chromatographically, and the structures were elucidated by extensive analyses of high-resolution 1H and 13C NMR data. The separated compounds were characterized as ß-sitosterol (1), ß-amyrin (2), ß-amyrin acetate (3), ß-amyrin palmitate (4), ß-amyrone (5), and isoscopoletin (6). DPPH free radical scavenging assay, tail-tipping method, writhing assay, and castor oil-induced diarrheal mice methods, respectively, were used to assess the antioxidant, hypoglycemic, analgesic, and anti-diarrheal activities of the leaf extract of B. ceiba plant species. The study observed significant reductions (p < 0.05) in the level of blood glucose at 30, 60, 120, and 180 min following the administration of the crude extracts (200 mg/kg body weight (bw) and 400 mg/kg bw). These reductions occurred in a time-dependent manner. Additionally, both doses of the investigated extracts exhibited significant (p < 0.05) central and peripheral analgesic effects compared to morphine (2 mg/kg bw) and diclofenac sodium (50 mg/kg bw), respectively. Furthermore, the 400 mg/kg bw extract demonstrated anti-diarrheal activity, reducing 54.17 % of diarrheal episodes in mice compared to loperamide with 70.83 % inhibition. The computational investigations yielded results consistent with existing in vivo findings. The results obtained from molecular docking showed that the isolated compounds had a better or comparable binding affinity to the active binding sites of the glutathione reductase enzyme, mu-opioid receptor, cyclooxygenase 2 (COX-2), glucose transporter 3 (GLUT 3), and kappa opioid receptor. These findings may indicate that the compounds isolated from the B. ceiba plant species have antioxidant, analgesic, hypoglycemic, and anti-diarrheal, properties. Consequently, it was inferred that the plant B. ceiba might be beneficial in dealing with oxidation, diarrhea, hyperglycemia, and pain. Nonetheless, further investigations are necessary to perform thorough phytochemical profiling and elucidate the exact mechanistic ways of the crude extract and the isolated phytoconstituents.

Comparison of the Effect of Kaolin and Bentonite Clay (Raw, Acid-Treated, and Metal-Impregnated) on the Pyrolysis of Waste Tire.

This study investigates the effectiveness of kaolin and bentonite catalysts in improving liquid hydrocarbon yields during the pyrolysis of waste tires. Raw clay, nitric acid-treated clay, and mono- or bimetal-impregnated clay were used as catalysts in the pyrolysis of waste tire. Acid-treated kaolin produced a higher yield of liquid hydrocarbons (43.24-47%) compared to acid-treated bentonite (35.34-41.85%). This improvement in the liquid yield can be attributed to the higher specific surface area and pore diameter of the acid-treated clay in comparison to raw kaolin (39.48%) and raw bentonite (31.62%). Moreover, the use of metal-impregnated catalysts, such as Fe/kaolin and Ni/Fe/kaolin, resulted in higher liquid yields (47%) compared to the 3 M HNO3-treated kaolin catalyst (43.24%). Gas chromatography-mass spectrometry (GC-MS) analysis confirmed the presence of limonene, a crucial ingredient for commercial perfume production, in the liquid products. The calorific values of oil obtained through kaolin and bentonite catalysis were measured at 13,922 and 10,174 kcal/kg, respectively, further highlighting the potential of these catalysts in waste tire valorization.

Multi-modal neuroprotection of Argemone mexicana L. against Alzheimer's disease: In vitro and in silico study.

Argemone mexicana L. is a medicinal plant, but its impact on Alzheimer's disease (AD) is right now undetermined. We intended to investigate the in-vitro anti-AD potential of leaves and flowers of A. mexicana methanol, ethanol, and ethyl extracts and to identify multi-modal anti-AD phytochemicals by computational approaches. Molecular docking of 196 phytochemicals identified three hit phytochemicals (protoberberine, protopine, and codeine) with higher binding affinity and multi-targeting ability toward AChE, BChE, BACE-1, and GSK-3ß. Further MM-GBSA assays confirmed the integrity of these phytochemicals as the hit phytochemicals. However, these phytochemicals demonstrated favorable pharmacokinetics (PK) and drugable properties having no toxicity. Molecular dynamics simulations confirmed the binding strength of the hit phytoconstituents in the active pockets of AChE, BChE, BACE-1, and GSK-3ß with multi-targeting inhibitory activities. All the extracts exhibited dose-dependent antioxidant and anti-cholinesterase activities supporting the in silico results in the context of oxidative stress and cholinergic pathways. Our results offer scientific validation of the anti-AD properties of Argemone mexicana L. and identified protoberberine, protopine, and codeine that could be used for the development of multi-modal inhibitors of AChE, BChE, BACE-1, and GSK-3ß to combat AD. Additional in vivo validation is recommended to ensure a thorough assessment in the present research.

Assessment of heavy metals and proximate composition in jellyfish (Lobonemoides robustus Stiasny, 1920) collected from Cox's Bazar coast: Human health risk assessment.

Jellyfish are known for experiencing periodic blooms in population, which occur when their density increases suddenly. The present study assessed the level of heavy metals and proximate composition in the jellyfish Lobonemoides robustus collected from Cox's Bazar coast of Bangladesh. This is the first study conducted in Bangladesh. Most of the studied metals were not possible to detect in L. robustus samples because concentrations were below the detection limit. Ca, Na, Se, and Mg were found to have safe levels in the L. robustus while the amount of Pb was recorded 0.39 ppm. The findings of Target Hazard Quotient, and Carcinogenic Risk indicate that the L. robustus is safe for human consumption (both for children and adults). Hence, it is suitable for consumption and can be exported. This study emphasizes the need for regular marine environment monitoring to ensure that the seafood harvested from these waters is safe for consumption.

SARS CoV-2 IgG positivity among the people in Dhaka city: An observation from the post vaccine period.

Immunity status after mass vaccination program against SARS CoV-2 has not been evaluated in Bangladesh. This study aims to assess the IgG response against SARS-CoV-2 among the vaccine receivers in Bangladesh. After signed consent, blood samples were tested for SARS CoV-2 IgG from volunteers between March, 21 and April, 22 using ELISA where IgG index ≥0.9 was considered as positive Among 3034 participants, IgG positivity was calculated approximately 82% for vaccine recipients; lowest (58%) during March-April, 21 which increased to 85-95% later. IgG positivity and mean index was 82% and 3.04 in vaccinated whereas 56% and 1.5 in unvaccinated cases. IgG positivity and mean index reduced with age: 90% and 2.56, 79% and 2.23, 73% and 2.13 in 18-40 y, 41-60 y, >60 y group respectively. Vaccinated with COVID-19 history showed highest IgG positivity and index (94% and 3.1) compared to vaccinated without COVID-19 history (76% and 1.6), unvaccinated with COVID-19 history (75% and 1.5) and unvaccinated without COVID-19 history (51% and 0.9). IgG positivity and index reduced as interval between IgG testing and vaccination increases. Our findings suggest a robust IgG response among the vaccine recipients. Negative correlation of IgG positivity and index with age and time necessitates continuous monitoring of immunity status.

Green-synthesized nanoparticles of the polyherbal extract attenuate the necrosis of pancreatic ß-cell in a streptozotocin-induced diabetic model.

Plant-based nanoformulation is one of the novel approaches for therapeutic benefits. This research synthesized a silver nanoparticle from the polyherbal combination of four plants/seeds (Momordica charantia, Trigonella foenum-graecum, Nigella sativa, and Ocimum sanctum) and investigated its antidiabetic effects in streptozotocin-induced Wistar albino rat model. The polyherbal extract (PH) was extracted by the Soxhlet-solvent extraction method and the resulting crude extract was undergone for silver nanoparticle synthesis. The PH extract was subjected to a four-week intervention in fructose-fed streptozotocin-induced Wistar Albino rats' models and in vitro antioxidative tests. Experimental animals (age: 6-7 weeks, male, body weight: 200-220 g), were divided into five groups including normal control (NC), reference control (RC), diabetic control (DC), and treatment groups PH200, PH100, and PHAgNP20. After three weeks of intervention, body weight, weekly blood glucose level, oral glucose tolerance test, AST, ALT, alkaline phosphatase, total cholesterol, triglycerides, uric acid, urea, and creatinine level of PH200 were found to be significantly (P < 0.05) improved compared to the diabetic control. The same dose demonstrated better regeneration of damaged pancreatic and kidney tissues. In vitro antioxidant assay manifested promising IC50 values of 86.17 µg/mL for DPPH, 711.04 µg/mL for superoxide free radical, and 0.48 mg/mL for Iron chelating activity of the polyherbal extract. GC-MS analysis impacted the major volatile compounds of the PH. The data demonstrate that the PH and its nanoparticles could be a novel source of antidiabetic therapeutics through an advanced dose-response study in the type 2 diabetic model.

GC-MS analysis and pharmacological evaluations of Phoenix sylvestris (Roxb.) seeds provide new insights into the management of oxidative stress and hyperglycemia.

Phoenix sylvestris Roxb. (Arecaceae) seeds are used in the treatment of diabetes in the traditional system of medicine. The present study evaluated antihyperglycemic and antioxidant activities as well as the total phenolic and flavonoid content of the methanol extract of P. sylvestris seeds (MEPS). The constituents of the extract were identified by GC-MS analysis. MEPS demonstrated strong antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC50 = 162.70 ± 14.99 µg) and nitric oxide (NO) (IC50 = 101.56 ± 9.46 µg/ml) free radicals. It also possesses a substantial amount of phenolics and flavonoids. It significantly (p < .05) reduced blood glucose levels in glucose-loaded and alloxan-induced diabetic mice at the doses of 150 and 300 mg/kg b.w., respectively. A total of 46 compounds were detected and identified by gas chromatography-mass spectroscopy (GC-MS) analysis, among which 8-methylisoquinoline N-oxide (32.82%) was predominant. The phytochemical study by GC-MS revealed that the MEPS possesses compounds which could be related to its antidiabetic and antioxidant activities. To recapitulate, P. sylvestris seeds can be a very good option for antidiabetic and antioxidant activity though further studies are still recommended to figure out the responsible phytochemicals and establish their exact mechanism of action.

Performance Evaluation of SARS-CoV-2 Viral Transport Medium Produced by Bangladesh Reference Institute for Chemical Measurements.

A viral transport medium (VTM) was developed following the Centers for Disease Control and Prevention, USA (US-CDC) standard operating procedure (SOP) DSR-052-05 with necessary improvisation and was used for storing coronavirus disease 2019 (COVID-19) swab specimens. Considering Bangladesh's supply chain and storage conditions, improvisation was essential for extending sample storage time while retaining efficiency. In-house VTM was produced using Hank's balanced salt solution (HBSS) supplemented with 1% bovine serum albumin V (BSA), 0.5 µg /mL of gentamicin sulfate, and 100 µg/mL of fluconazole. The produced VTM composition, quality, sterility, specificity, and efficiency were verified in-house and through an independent contract research organization (CRO). An accelerated stability study projected that under the recommended temperature (4 °C), it would remain stable for four months and preserve samples for over a month. The real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) test detected the targeted N gene and ORF1ab gene from the VTM stored samples. Our VTM is equally as effective as the Sansure Biotech VTM in keeping SARS-CoV-2 RNA specimens detectable in rRT-PCR (100% sensitivity and specificity in random and blinded samples). In conclusion, the BRiCM VTM will make the battle against pandemics easier by effectively collecting and storing nasopharyngeal and oropharyngeal swabs for COVID-19 detection.

Natural defense against multi-drug resistant Pseudomonas aeruginosa: Cassia occidentalis L. in vitro and in silico antibacterial activity.

Cassia occidentalis L. is widely used in indigenous and traditional medicine, but its impact on multi-drug resistant (MDR) bacterial infections mostly remains unknown. Therefore, this study aimed to evaluate the in vitro antibacterial efficiency of methanol and ethyl acetate extracts of C. occidentalis L. leaves (MECOL and EAECOL) against multi-drug resistant Pseudomonas aeruginosa and to identify potential antibacterial agents through computational studies targeting the LasR protein. Initially, 82 compounds were identified using GC-MS analysis, and the functional groups were determined through FT-IR analysis. Both extracts of the plant exhibited dose-dependent antibacterial activity, with MICs of 104.16 ± 36.08 µg mL-1 for MECOL and 83.33 ± 36.08 µg mL-1 for EAECOL, and an MBC of 125 µg mL-1. Among the 82 compounds, 12 potential compounds were identified based on binding scores using molecular docking with the LasR protein and MM-GBSA analysis. Furthermore, screening for ADME properties, including physicochemical features, water solubility, lipophilicity, RO5 compliance, and toxicity, identified the top three compounds: methyl dihydrojasmonate, methyl benzoate, and 4a-methyl-4,4a,5,6,7,8-hexahydro-2(3H)-naphthalenone, which also demonstrated binding affinity with the active site residues of the LpxC protein of the bacteria. Additionally, molecular dynamics (MD) simulations confirmed the binding reliability of these three phytochemicals to LasR's active pocket, comparable to the protein native inhibitory ligands (C12-HSL). The study offers scientific support for the traditional use of C. occidentalis in treating bacterial infections, highlighting the potential of the three compounds as leads for developing LasR inhibitors to combat multi-drug resistant P. aeruginosa.

Effects of gamma-radiation on microbial, nutritional, and functional properties of Katimon mango peels: A combined biochemical and in silico studies.

Gamma radiation has notable impacts on the flesh of mangoes. In this research, Katimon mangoes were subjected to different levels of irradiation (0.5, 1.0, 1.5, and 2.0 kGy) using a60Co irradiator. The results showed that irradiation significantly reduced the microbial population in the mango peels, with the 1.5 kGy dose showing the most significant reduction. Irradiation also delayed ripening and extended the shelf life of the mango peels. The total fat, protein, ash, moisture, and sugar content of the mango peels were all affected by irradiation. The total protein content, ash content and moisture content increased after irradiation, while the fat content remained relatively unchanged. The sugar content increased in all samples after storage, but the non-irradiated samples had higher sugar levels than the irradiated ones. The dietary fiber content of the mango peels was not significantly affected by irradiation. The vitamin C content decreased in all samples after storage. The titratable acidity and total soluble solids content of the mango peels increased after storage, but there were no significant differences between the irradiated and non-irradiated samples. Antioxidant activity and cytotoxicity assessment highlighted the antioxidant potential and reduced toxicity of irradiated samples. Additionally, the antimicrobial effectiveness of irradiated mango peels was evaluated. The most substantial inhibitory zones (measuring 16.90 ± 0.35) against Pseudomonas sp. were observed at a radiation dose of 1.5 kGy with 150 µg/disc. To identify potential antimicrobial agents, the volatile components of mangoes irradiated with 1.5 kGy were analyzed through GC-MS. Subsequently, these compounds were subjected to in silico studies against a viable protein, TgpA, of Pseudomonas sp. (PDB ID: 6G49). Based on molecular dynamic simulations and ADMET properties, (-)-Carvone (-6.2), p-Cymene (-6.1), and Acetic acid phenylmethyl ester (-6.1) were identified as promising compounds for controlling Pseudomonas sp.

Seropositivity of SARS-CoV-2 IgG Antibody among People in Dhaka City during the Prevaccination Period.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) detection can be an effective complementary tool to the reverse transcription-polymerase chain reaction (RT-PCR) test in estimating the true burden of coronavirus diseases 2019 (COVID-19) and can serve as baseline data, especially after the roll-out of vaccines against SARS-CoV-2. In this study, we aim to determine the seropositivity of SARS-CoV-2 IgG among people in Dhaka, Bangladesh. Volunteers, mostly asymptomatic people from Dhaka, were enrolled between October 2020 and February 2021. After obtaining participants' signed consents, blood samples were tested for SARS-CoV-2 IgG antibody, following the standard protocol of testing within 72 hours of collection. SARS-CoV-2 IgG was positive in 42% (101/239) of the cases. No difference was observed in terms of IgG positivity and IgG levels when stratified by age, gender, and blood group. However, RT-PCR-positive cases presented higher IgG levels compared to RT-PCR-negative/RT-PCR-not performed cases. SARS-CoV-2 IgG was found in 31% (32/102) and 28% (19/67) of RT-PCR-negative and RT-PCR-not performed cases, respectively. For RT-PCR-positive but SARS-CoV-2 IgG-negative cases (n = 13), the average time gap between the RT-PCR and SARS-CoV-2 IgG tests of six months indicates a gradual reduction of IgG. Eight cases for which samples were tested at two time points, three months apart, showed presented a decline in IgG levels with time (median IgG index of 2.55 in the first sample versus 1.22 in the second sample). Our findings reveal that several mild/asymptomatic cases that were RT-PCR-negative/not tested exist in the community, and IgG levels reduce in the human body over time.