Antimicrobial, antioxidant, and cytotoxic activities of Bixa orellana Linn

Bixa orellana Linn., commonly known as "lipstick plant", is used in folk medicines to treat infections of microbial origin as well as coloring agents in food stuffs in the LDCs like Bangladesh. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the warm water extract of leaves of B. orellana were evaluated against 25 multidrug resistant (MDR) clinical isolates and 6 food-borne pathogens using the micro-dilution broth method modified to comply with the NCCLS standards. The total phenolic content and antioxidant capacity of warm water, ethanol, and methanol extracts of the seeds and leaves of B. orellana were also evaluated. The brine shrimp lethality assay was conducted to assess the toxicity of the extracts. Except Pseudomonas spp., all the MDR isolates and food-borne pathogens tested were susceptible to the warm water extract of the leaves. The MIC and MBC ranged between 8-256 μg/mL and 16 - 256 μg/mL, respectively. Among the test organisms, Streptococcus spp. and Shigella dysenteriae-1 MJ-84 showed highest susceptibility while Escherichia coli exhibited moderate susceptibility to warm water extract of the leaves. The highest total phenolic content (99.99 mg of GAE/g of extractives) and antioxidant capacity (IC50 value 13 μg/mL) were observed in ethanolic extract of seeds of B. orellana, whereas the IC50 of the reference standard BHT (tert-butyl-1-hydroxytoluene) was 59.2 μg/mL. On the other hand, in the brine shrimp lethality bioassay the methanolic extract of the seeds of B. orellana demonstrated strong cytotoxic activity with IC50 value of 19.3 μg/mL. These results suggest that the extracts of B. orellana possess bioactive compoundsColegio de Farmacéuticos de la Provincia de Buenos Aire

Use of Phages to Treat Antimicrobial-Resistant Salmonella Infections in Poultry

Salmonellosis is one of the most common bacterial infections that impacts both human health and poultry production. Although antibiotics are usually recommended for treating Salmonella infections, their misuse results in the evolution and spread of multidrug-resistant (MDR) bacteria. To minimize the health and economic burdens associated with antimicrobial resistance, a novel antibacterial strategy that can obliterate pathogens without any adverse effects on humans and animals is urgently required. Therefore, therapeutic supplementation of phages has gained renewed attention because of their unique ability to lyse specific hosts, cost-effective production, environmentally-friendly properties, and other potential advantages over antibiotics. In addition, the safety and efficacy of phage therapy for controlling poultry-associated Salmonella have already been proven through experimental studies. Phages can be applied at every stage of poultry production, processing, and distribution through different modes of application. Despite having a few limitations, the optimized and regulated use of phage cocktails may prove to be an effective option to combat infections caused by MDR pathogens in the post-antibiotic era. This article mainly focuses on the occurrence of salmonellosis in poultry and its reduction with the aid of bacteriophages. We particularly discuss the prevalence of Salmonella infections in poultry and poultry products; review the trends in antibiotic resistance; and summarize the application, challenges, and prospects of phage therapy in the poultry industry

Saccharification of Sugarcane Bagasse by Enzymatic Treatment for bioethanol production

ABSTRACT Aims: The escalating demands for traditional fossil fuels with unsecured deliverance and issues of climate change compel the researchers to develop alternative fuels like bioethanol. This study examines the prospect of biofuel production from high carbohydrate containing lignocellulosic material, e.g. sugarcane bagasse through biological means. Methodology and Results: Cellulolytic enzymes were collected from the culture filtrate of thermotolerant Trichoderma viride grown on variously pre-treated sugarcane bagasse. CMCase and FPase enzyme activities were determined as a measure of suitable substrate pre-treatment and optimum condition for cellulolytic enzyme production. The highest CMCase and FPase activity was found to be 1.217 U/ml and 0.109 U/ml respectively under the production conditions of 200 rpm, pH 4.0 and 50 °C using steamed NaOH treated bagasse as substrate. SEM was carried out to compare and confirm the activity of cellulolytic enzymes on sugarcane bagasse. Saccharification of pre-treated bagasse was carried out with crude enzymes together using a two-factor experimental design. Under optimized conditions the pre-treated bagasse was saccharified up to 42.7 % in 24 h. The hydrolysate was concentrated by heating to suitable concentration and then used for fermentation by an indigenous isolate of Saccharomyces cerevisiae. With 50 and 80 % brix containing liquor the concentration of alcohol was 0.579 % and 1.15 % respectively. Conclusion, significance and impact of study: This is the first report in Bangladesh for the production of cellulosic ethanol using local isolates. Though the rate of alcohol production was very low, a great impetus in this field can maximize the production thereby meet the demand for fuel in future

Subtractive proteomic analysis for identification of potential drug targets and vaccine candidates against Burkholderia pseudomallei K96243

Burkholderia pseudomallei is regarded as a global threat because of its ability to cause melioidosis, and potential as bioweapon. Intrinsic resistance to frontline antibiotics remains a major challenge in treating melioidosis. The increasing global burden of B. pseudomallei triggers the need to develop effective drugs and vaccine for controlling this pathogen. Therefore, we analyzed the whole proteome of B. pseudomallei K96243 using subtractive proteomic and immune-informatic analysis to find out potential drug target and vaccine candidate. Our analysis revealed 45 essential and non-homologous metabolic proteins, involved in different unique metabolic pathways. 36 out of 45 proteins can serve as novel drug targets and the remaining proteins had already been targeted with experimental drugs. 2 novel targets of cytoplasmic localization, namely dihydroneopterin aldolase and phosphoribosyl transferase were subjected to molecular docking with 14 antibiotics, which revealed the strong binding affinity of cefiderocol and tetracycline to the identified targets. Moreover, 100 ns molecular dynamic simulation and MM-PBSA calculation revealed the stability of drug-protein complexes. On the contrary, highly antigenic, non-allergic and non-toxic epitopes from three essential outer membrane proteins were joined by linkers and adjuvant to construct a chimeric peptide vaccine. The vaccine construct could efficiently bind to TLR-4 and generated robust immune response. The vaccine-receptor complex showed minimum deformability and good stability. Overall, our findings will aid in designing new inhibitors that disrupts the functionality of proposed targets and in the development of subunit vaccine for the therapeutic and prophylactic management of B. pseudomallei

Molecular docking and dynamics simulation study of medicinal fungi derived secondary metabolites as potential inhibitor for COVID-19 treatment

The severity of COVID-19, lack of specific treatment, and controversies on the vaccine's efficacy demand the development of new drugs against SARS-CoV-2. Fungi produce various metabolites with diverse molecular structures that have emerged as promising antiviral drug candidates. Therefore, the present study aimed to investigate medicinal fungi derived secondary metabolites as potential inhibitors of 3 different targets associated with viral entry (human TMPRSS2) and replication (main and papain-like protease) through molecular docking and dynamic simulation studies. Based on our findings, we identified Phelligridin E, Lepiotaprocerine G, and Inoscavin A as the potential blockers of SARS-CoV-2 main protease, papain-like protease, and human TMPRSS2, respectively. These compounds strongly interacted with their corresponding target, passed Lipinski Rule's and had acceptable ADMET properties. Drug-protein complexes showed good stability during MD simulation. Estimation of binding free energy using the MM-GBSA method validated the inhibitor potential of identified compounds. Taken together, we believe that further in vitro and in vivo investigations on our proposed molecules may contribute to expanding the therapeutic arsenal in our fight against COVID-19

Phenotypic characterization and genomic analysis of a Salmonella phage L223 for biocontrol of Salmonella spp. in poultry

Abstract The escalating incidence of foodborne salmonellosis poses a significant global threat to food safety and public health. As antibiotic resistance in Salmonella continues to rise, there is growing interest in bacteriophages as potential alternatives. In this study, we isolated, characterized, and evaluated the biocontrol efficacy of lytic phage L223 in chicken meat. Phage L223 demonstrated robust stability across a broad range of temperatures (20–70 °C) and pH levels (2–11) and exhibited a restricted host range targeting Salmonella spp., notably Salmonella Typhimurium and Salmonella Enteritidis. Characterization of L223 revealed a short latent period of 30 min and a substantial burst size of 515 PFU/cell. Genomic analysis classified L223 within the Caudoviricetes class, Guernseyvirinae subfamily and Jerseyvirus genus, with a dsDNA genome size of 44,321 bp and 47.9% GC content, featuring 72 coding sequences devoid of antimicrobial resistance, virulence factors, toxins, and tRNA genes. Application of L223 significantly (p < 0.005) reduced Salmonella Typhimurium ATCC 14,028 counts by 1.24, 2.17, and 1.55 log CFU/piece after 2, 4, and 6 h of incubation, respectively, in experimentally contaminated chicken breast samples. These findings highlight the potential of Salmonella phage L223 as a promising biocontrol agent for mitigating Salmonella contamination in food products, emphasizing its relevance for enhancing food safety protocols

Phylogenetic diversity and functional potential of large and cell-associated viruses in the Bay of Bengal

ABSTRACT The Bay of Bengal (BoB) is the world’s largest bay, offering essential services like fishing and recreation while holding significant economic value for coastal communities. However, the BoB faces environmental challenges from monsoons, freshwater inputs, rising sea levels, and intensified cyclones due to climate change. Human activities such as tourism and development also impact the region, necessitating a global change perspective. Despite its importance, microbial diversity and ecology in the BoB remain largely unexplored. We focused on large and cell-associated viruses (i.e., originating from the cellular size fraction), particularly giant viruses and large phages in two BoB coastal sites: Cox’s Bazar, a populated beach with freshwater influences, and Saint Martin Island, a less affected resort island. Metagenomic sequencing reveals a higher abundance and diversity of viruses in Cox’s Bazar and presence of viruses that suggest freshwater intrusion and runoff. We identified 1962 putative phage genomes (10–655 kbp). Notably, 16 “large” phages >100 kbp were found in Saint Martin, and a terminase large subunit marker gene phylogeny revealed substantial diversity of large phages along the BoB coast. The BoB virome encodes diverse functionalities, with a greater presence of auxiliary metabolic genes in the Cox’s Bazar viral community. Additionally, five giant virus genomes (phylum Nucleocytoviricota) encoding various functionalities are reconstructed from Cox’s Bazar (83–876 kbp). This pioneering study revealing the viral diversity and host interactions in coastal BoB lays the foundation for future investigations into viral impact on biogeochemical cycles and the microbial food web in this understudied environment. IMPORTANCE The BoB, the world’s largest bay, is of significant economic importance to surrounding countries, particularly Bangladesh, which heavily relies on its coastal resources. Concurrently, the BoB holds substantial ecological relevance due to the region’s high vulnerability to climate change-induced impacts. Yet, our understanding of the BoB’s microbiome in relation to marine food web and biogeochemical cycling remains limited. Particularly, there are little or no data on the viral diversity and host association in the BoB. We examined the viral community in two distinct BoB coastal regions to reveal a multitude of viral species interacting with a wide range of microbial hosts, some of which play key roles in coastal biogeochemical cycling or potential pathogens. Furthermore, we demonstrate that the BoB coast harbors a diverse community of large and giant viruses, underscoring the importance of investigating understudied environments to discover novel viral lineages with complex metabolic capacities. The BoB, the world’s largest bay, is of significant economic importance to surrounding countries, particularly Bangladesh, which heavily relies on its coastal resources. Concurrently, the BoB holds substantial ecological relevance due to the region’s high vulnerability to climate change-induced impacts. Yet, our understanding of the BoB’s microbiome in relation to marine food web and biogeochemical cycling remains limited. Particularly, there are little or no data on the viral diversity and host association in the BoB. We examined the viral community in two distinct BoB coastal regions to reveal a multitude of viral species interacting with a wide range of microbial hosts, some of which play key roles in coastal biogeochemical cycling or potential pathogens. Furthermore, we demonstrate that the BoB coast harbors a diverse community of large and giant viruses, underscoring the importance of investigating understudied environments to discover novel viral lineages with complex metabolic capacities

Differences in lineage replacement dynamics of G1 and G2 rotavirus strains versus G9 strain over a period of 22 years in Bangladesh

Group A rotaviruses (RVAs) have been a major cause of severe gastroenteritis in Bangladesh, mainly in children below the age of five. At the icddr,b, RVA strains collection and characterization dates back for more than 20years. This sample collection was used to study the molecular evolution of the VP7 gene of G1, G2 and G9 RVA strains, which have been circulating in Bangladesh for most of this study period. The evolutionary rates (95% HPD) for G1, G2 and G9 were calculated to be 0.93×10 (0.68-1.18), 1.45×10 (1.12-1.78) and 1.07×10 (0.78-1.39), respectively, which is in line with previous data for the RVA VP7 outer capsid protein, which is under strong negative selective pressure. Bayesian analyses revealed that for the G1 and G2 genotypes, one or multiple lineages co-circulated for one or a few seasons, frequently followed by replacement with genetically different lineages. This can be explained by the existence of a large variety of G1 and G2 RVA lineages and the rapid dissemination of different lineages across the globe. In contrast, circulating G9 lineages were rather closely related to each other across the study period and they were usually derived from variants circulating in the previous season(s). This is consistent with the fact that G9 RVAs have circulated in the human population for less than 20years, and therefore their genetic diversity is much smaller, not resulting in the replacement of circulating G9 strains by highly divergent G9 lineages from abroad. Such different evolutionary dynamics for different RVA genotypes may alter their response to the selective pressure that might be exerted by the introduction of RVA vaccines and therefore a continued close monitoring is warranted

Differences in lineage replacement dynamics of G1 and G2 rotavirus strains versus G9 strain over a period of 22years in Bangladesh

Group A rotaviruses (RVAs) have been a major cause of severe gastroenteritis in Bangladesh, mainly in children below the age of five. At the icddr,b, RVA strains collection and characterization dates back for more than 20years. This sample collection was used to study the molecular evolution of the VP7 gene of G1, G2 and G9 RVA strains, which have been circulating in Bangladesh for most of this study period. The evolutionary rates (95% HPD) for G1, G2 and G9 were calculated to be 0.93×10(-)(3) (0.68-1.18), 1.45×10(-)(3) (1.12-1.78) and 1.07×10(-)(3) (0.78-1.39), respectively, which is in line with previous data for the RVA VP7 outer capsid protein, which is under strong negative selective pressure. Bayesian analyses revealed that for the G1 and G2 genotypes, one or multiple lineages co-circulated for one or a few seasons, frequently followed by replacement with genetically different lineages. This can be explained by the existence of a large variety of G1 and G2 RVA lineages and the rapid dissemination of different lineages across the globe. In contrast, circulating G9 lineages were rather closely related to each other across the study period and they were usually derived from variants circulating in the previous season(s). This is consistent with the fact that G9 RVAs have circulated in the human population for less than 20years, and therefore their genetic diversity is much smaller, not resulting in the replacement of circulating G9 strains by highly divergent G9 lineages from abroad. Such different evolutionary dynamics for different RVA genotypes may alter their response to the selective pressure that might be exerted by the introduction of RVA vaccines and therefore a continued close monitoring is warranted.publisher: Elsevier articletitle: Differences in lineage replacement dynamics of G1 and G2 rotavirus strains versus G9 strain over a period of 22years in Bangladesh journaltitle: Infection, Genetics and Evolution articlelink: http://dx.doi.org/10.1016/j.meegid.2014.10.002 content_type: article copyright: Copyright © 2014 Elsevier B.V. All rights reserved.status: publishe

Phylogenetic diversity and functional potential of the microbial communities along the Bay of Bengal coast

Abstract The Bay of Bengal, the world's largest bay, is bordered by populous countries and rich in resources like fisheries, oil, gas, and minerals, while also hosting diverse marine ecosystems such as coral reefs, mangroves, and seagrass beds; regrettably, its microbial diversity and ecological significance have received limited research attention. Here, we present amplicon (16S and 18S) profiling and shotgun metagenomics data regarding microbial communities from BoB’s eastern coast, viz., Saint Martin and Cox’s Bazar, Bangladesh. From the 16S barcoding data, Proteobacteria appeared to be the dominant phylum in both locations, with Alteromonas, Methylophaga, Anaerospora, Marivita, and Vibrio dominating in Cox’s Bazar and Pseudoalteromonas, Nautella, Marinomonas, Vibrio, and Alteromonas dominating the Saint Martin site. From the 18S barcoding data, Ochrophyta, Chlorophyta, and Protalveolata appeared among the most abundant eukaryotic divisions in both locations, with significantly higher abundance of Choanoflagellida, Florideophycidae, and Dinoflagellata in Cox’s Bazar. The shotgun sequencing data reveals that in both locations, Alteromonas is the most prevalent bacterial genus, closely paralleling the dominance observed in the metabarcoding data, with Methylophaga in Cox’s Bazar and Vibrio in Saint Martin. Functional annotations revealed that the microbial communities in these samples harbor genes for biofilm formation, quorum sensing, xenobiotics degradation, antimicrobial resistance, and a variety of other processes. Together, these results provide the first molecular insight into the functional and phylogenetic diversity of microbes along the BoB coast of Bangladesh. This baseline understanding of microbial community structure and functional potential will be critical for assessing impacts of climate change, pollution, and other anthropogenic disturbances on this ecologically and economically vital bay