An immunoinformatics and structural vaccinology study to design a multi-epitope vaccine against Staphylococcus aureus infection.

Staphylococcus aureus has been widely reported to be majorly responsible for causing nosocomial infections worldwide. Due to an increase in antibiotic-resistant strains, the development of an effective vaccine against the bacteria is the most viable alternative. Therefore, in the current work, an effort has been undertaken to develop a novel peptide-based vaccine construct against S aureus that can potentially evoke the B and T cell immune responses. The fibronectin-binding proteins are an attractive target as they play a prominent role in bacterial adherence and host cell invasion and are also well conserved among rapidly mutating pathogens. Therefore, highly immunogenic linear B lymphocytes (LBL), cytotoxic T lymphocytes (CTL), and helper T lymphocytes (HTL) epitopes were identified from the antigenic fibronectin-binding proteins A and B (FnBPA and FnBPB) of S aureus using immunoinformatics approaches. The selected peptides were confirmed to be non-allergenic, non-toxic, and with a high binding affinity to the majority of human leukocyte antigens (HLA) alleles. Consequently, the multi-peptide vaccine construct was developed by fusing the screened epitopes (three LBL, five CTL, and two HTL) together with the suitable adjuvant and linkers. In addition, the tertiary conformation of the peptide construct was modeled and later docked to the Toll-like receptor 2. Subsequently, a molecular dynamics simulation of 100 ns was employed to corroborate the stability of the designed vaccine-receptor complex. Besides exhibiting high immunogenicity and conformational stability, the developed vaccine was observed to possess wide population coverage of 99.51% worldwide. Additional in vivo and in vitro validation studies would certainly corroborate the designed vaccine construct to have improved prophylactic efficacy against S aureus.

Nanotechnological interventions in bacteriocin formulations - advances, and scope for challenging food spoilage bacteria and drug-resistant foodborne pathogens.

Food spoilage bacteria (FSB) and multidrug-resistant (MDR) foodborne pathogens have emerged as one of the principal public health concerns in the twenty first century. The harmful effects of FSB lead to economic losses for the food industries. Similarly, MDR foodborne pathogens are accountable for multiple illnesses and pose a threat to consumers. Therefore, there is an urgent need to establish effective formulations for successful application against such microorganisms. In this context, the fusion of knowledge from biotechnology and nanotechnology can explore endless possibilities in the development of innovative formulations against FSB and foodborne pathogens. The current review critically examines the application of bacteriocins in the food industry and the use of nanomaterials to enhance the antimicrobial activity, stability, and precision in the target delivery of bacteriocins. This review also explores the technologies involved in the development of bacteriocin-based nanoformulations and their action against FSB and MDR foodborne pathogens, offering new possibilities in preservation technologies and addressing food safety issues in the food industry. The review highlights the challenges in the commercialization and technoeconomical feasibility of nanobacteriocin. Overall, it provides essential information and interpretation about nanotechnological advancements in bacteriocin formulation action against FSB and foodborne pathogens and future scopes.

Identification of potential flavonoid compounds as antibacterial therapeutics against Klebsiella pneumoniae infection using structure-based virtual screening and molecular dynamics simulation.

Klebsiella pneumoniae, which is among the top three pathogens on WHO's priority list, is one of the gram-negative bacteria that doctors and researchers around the world have fought for decades. Capsular polysaccharide (CPS) protein is extensively recognized as an important K. pneumoniae virulence factor. Thus, CPS has become the most characterized target for the discovery of novel drug candidates. The ineffectiveness of currently existing antibiotics urges the search for potent antimicrobial compounds. Flavonoids are a group of plant metabolites that have antibacterial potential and can enhance the present medications to elicit improved results against diverse diseases without adverse reactions. Henceforth, the present study aims to illustrate the inhibitory potential of flavonoids with varying pharmacological properties, targeting the CPS protein of K. pneumoniae by in silico approaches. The flavonoid compounds (n = 169) were retrieved from the PubChem database and screened using the structure-based virtual screening approach. Compounds with the highest binding score were estimated through their pharmacokinetic effects by ADMET descriptors. Finally, four potential inhibitors with PubChem CID: (4301534, 5213, 5481948, and 637080) were selected after molecular docking and drug-likeness analysis. All four lead compounds were employed for the MDS analysis of a 100 ns time period. Various studies were undertaken to assess the stability of the protein-ligand complexes. The binding free energy was computed using MM-PBSA, and the outcomes indicated that the molecules are having stable interactions with the binding site of the target protein. The results revealed that all four compounds can be employed as potential therapeutics against K. pneumoniae.

Atmospheric microplastic and nanoplastic: The toxicological paradigm on the cellular system.

The increasing demand for plastic in our daily lives has led to global plastic pollution. The improper disposal of plastic has resulted in a massive amount of atmospheric microplastics (MPs), which has further resulted in the production of atmospheric nanoplastics (NPs). Because of its intimate relationship with the environment and human health, microplastic and nanoplastic contamination is becoming a problem. Because microplastics and nanoplastics are microscopic and light, they may penetrate deep into the human lungs. Despite several studies demonstrating the abundance of microplastics and nanoplastics in the air, the potential risks of atmospheric microplastics and nanoplastics remain unknown. Because of its small size, atmospheric nanoplastic characterization has presented significant challenges. This paper describes sampling and characterization procedures for atmospheric microplastics and nanoplastics. This study also examines the numerous harmful effects of plastic particles on human health and other species. There is a significant void in research on the toxicity of airborne microplastics and nanoplastics upon inhalation, which has significant toxicological potential in the future. Further study is needed to determine the influence of microplastic and nanoplastic on pulmonary diseases.

Exploiting AGPase genes and encoded proteins to prioritize development of optimum engineered strains in microalgae towards sustainable biofuel production.

Although ADP glucose pyrophosphorylase (AGPase), with two large subunits (ls) and two small subunits (ss), is a promising knockout target for increasing the neutral lipid content, the details regarding the sequence-structure features and their distribution within metabolic system in microalgae is rather limited. Against this backdrop, a comprehensive genome-wide comparative analysis on 14 sequenced microalgal genomes was performed. For the first time the heterotetrameric structure of the enzyme and the interaction of the catalytic unit with the substrate was also studied. Novel findings of the present study includes: (i) at the DNA level, the genes controlling the ss are more conserved than those controlling the ls; the variation in both the gene groups is mainly due to exon number, exon length and exon phase distribution; (ii) at protein level, the ss genes are more conserved relative to those for ls; (III) three putative key consensus sequences 'LGGGAGTRLYPLTKNRAKPAV', 'WFQGTADAV' and 'ASMGIYVFRKD' were ubiquitously conserved in all the AGPases; (iv) molecular dynamics investigations revealed that the modeled AGPase heterotetrameric structure, from oleaginous algae Chlamydomonas reinharditii, was completely stable in real time environment; (v) The binding interfaces of catalytic unit, ssAGPase, from C. reinharditii with α-D-glucose 1-phosphate (αGP) was also analyzed. The results of the present study have provided system-based insights into the structure-function of the genes and encoded proteins, which provided clues for exploitation of variability in these genes that, could be further utilized to design site-specific mutagenic experiments for engineering of microalgal strains towards sustainable development of biofuel.

Comparative Analysis of Host Metabolic Alterations in Murine Malaria Models with Uncomplicated or Severe Malaria.

Malaria varies in severity, with complications ranging from uncomplicated to severe malaria. Severe malaria could be attributed to peripheral hyperparasitemia or cerebral malaria. The metabolic interactions between the host and Plasmodium species are yet to be understood during these infections of varied pathology and severity. An untargeted metabolomics approach utilizing the liquid chromatography-mass spectrometry platform has been used to identify the affected host metabolic pathways and associated metabolites in the serum of murine malaria models with uncomplicated malaria, hyperparasitemia, and experimental cerebral malaria. We report that mice with malaria share similar metabolic attributes like higher levels of bile acids, bile pigments, and steroid hormones that have been reported for human malaria infections. Moreover, in severe malaria, upregulated levels of metabolites like phenylalanine, histidine, valine, pipecolate, ornithine, and pantothenate, with decreased levels of arginine and hippurate, were observed. Metabolites of sphingolipid metabolism were upregulated in experimental cerebral malaria. Higher levels of 20-hydroxy-leukotriene B4 and epoxyoctadecamonoenoic acids were found in uncomplicated malaria, with lower levels observed for experimental cerebral malaria. Our study provides insights into host biology during different pathological stages of malaria disease and would be useful for the selection of animal models for evaluating diagnostic and therapeutic interventions against malaria. The raw data files are available via MetaboLights with the identifier MTBLS4387.

The Hha-TomB toxin-antitoxin module in Salmonella enterica serovar Typhimurium limits its intracellular survival profile and regulates host immune response.

The key to bacterial virulence relies on an exquisite balance of signals between microbe and hosts. Bacterial toxin-antitoxin (TA) system is known to play a vital role in response to stress adaptation, drug resistance, biofilm formation, intracellular survival, persistence as well as pathogenesis. In the present study, we investigated the role of Hha-TomB TA system in regulating virulence of Salmonella enterica serovar Typhimurium (S. Typhimurium) in a host model system, where we showed that deletion of hha and tomB genes displayed impaired cell adhesion, invasion, and uptake. The isogenic hha and tomB mutant strain was also found to be deficient in intracellular replication in vitro, with a highly repressed Salmonella Pathogenicity Island-2 (SPI-2) genes and downregulation of Salmonella Pathogenicity Island-1 (SPI-1) genes. In addition, the Δhha and ΔtomB did not show acute colitis in C57BL/6 mice and displayed less dissemination to systemic organs followed by their cecal pathology. The TA mutants also showed reduction in serum cytokine and nitric oxide levels both in vitro and in vivo. However, the inflammation phenotype was restored on complementing strain of TA gene to its mutant strain. In silico studies depicted firm interaction of Hha-TomB complex and the regulatory proteins, namely, SsrA, SsrB, PhoP, and PhoQ. Overall, we demonstrate that this study of Hha-TomB TA system is one of the prime regulating networks essential for S. Typhimurium pathogenesis. 1. Role of Hha-TomB toxin-antitoxin (TA) system in Salmonella pathogenesis was examined. 2. The TA mutants resulted in impaired invasion and intracellular replication in vitro. 3. The TA mutants displayed alteration in SPI-1 and SPI-2 regulatory genes inside host cells. 4. Mutation in TA genes also limited systemic colonization and inflammatory response in vivo.

Hydoxylated ß- and δ-Hexacholorocyclohexane metabolites infer influential intrinsic atomic pathways interaction to elicit oxidative stress-induced apoptosis for bio-toxicity.

Hexachlorocyclohexane (HCH) has been recognized as an effective insecticide to protect crops against grasshoppers, cohort insects, rice insects, wireworms, and other agricultural pests and; for the control of vector-borne diseases such as malaria. It is a cyclic, saturated hydrocarbon, which primarily exists as five different stable isomers in the environment. Though the use of HCH is banned in most countries owing to its adverse effects on the environment, its metabolites still exist in soil and groundwater, because of its indiscriminate applications. In this study, a dose-dependent toxicity assay of the HCH isomers isolated from soil and water samples of different regions of Odisha, India was performed to assess the in vivo developmental effects and oxidative stress in zebrafish embryos. Toxicity analysis revealed a significant reduction in hatching and survivability rate along with morphological deformities (edema, tail malformations, spinal curvature) upon an increase in the concentration of HCH isomers; beta isomer exhibiting maximum toxicity (p < 0.05). Oxidative stress assay showed that ROS and apoptosis were highest in the fish exposed to ß-2 and δ-2 isomers of HCH in comparison to the untreated one. Zebrafish proved to be a useful biological model to assess the biological effects of HCH isomers. In addition, the results suggest the implementation of precautionary measures to control the use of organochlorine compounds that can lead to a decrease in the HCH isomers in the field for a healthier environment.

Emerging trends in the nanomedicine applications of functionalized magnetic nanoparticles as novel therapies for acute and chronic diseases.

High-quality point-of-care is critical for timely decision of disease diagnosis and healthcare management. In this regard, biosensors have revolutionized the field of rapid testing and screening, however, are confounded by several technical challenges including material cost, half-life, stability, site-specific targeting, analytes specificity, and detection sensitivity that affect the overall diagnostic potential and therapeutic profile. Despite their advances in point-of-care testing, very few classical biosensors have proven effective and commercially viable in situations of healthcare emergency including the recent COVID-19 pandemic. To overcome these challenges functionalized magnetic nanoparticles (MNPs) have emerged as key players in advancing the biomedical and healthcare sector with promising applications during the ongoing healthcare crises. This critical review focus on understanding recent developments in theranostic applications of functionalized magnetic nanoparticles (MNPs). Given the profound global economic and health burden, we discuss the therapeutic impact of functionalized MNPs in acute and chronic diseases like small RNA therapeutics, vascular diseases, neurological disorders, and cancer, as well as for COVID-19 testing. Lastly, we culminate with a futuristic perspective on the scope of this field and provide an insight into the emerging opportunities whose impact is anticipated to disrupt the healthcare industry.

In vivo intrinsic atomic interaction infer molecular eco-toxicity of industrial TiO2 nanoparticles via oxidative stress channelized steatosis and apoptosis in Paramecium caudatum.

The ecotoxicological effect of after-usage released TiO2 nanoparticles in aquatic resources has been a major concern owing to their production and utilization in different applications. Addressing the issue, this study investigates the detailed in vivo molecular toxicity of TiO2 nanoparticles with Paramecium caudatum. TiO2 nanoparticles were synthesized at a lab scale using high energy ball milling technique; characterized for their physicochemical properties and investigated for their ecotoxicological impact on oxidative stress, steatosis, and apoptosis of cells through different biochemical analysis, flow cytometry, and fluorescent microscopy. TiO2 nanoparticles; TiO2 (N15); of size 36 ± 12 nm were synthesized with a zeta potential of - 20.2 ± 8.8 mV and bandgap of 4.6 ± 0.3 eV and exhibited a blue shift in UV-spectrum. Compared to the Bulk TiO2, the TiO2 (N15) exhibited higher cytotoxicity with a 24 h LC50 of 202.4 µg/ml with P. Caudatum. The mechanism was elucidated as the size and charge-dependent internalization of nanoparticles leading to abnormal physiological metabolism in oxidative stress, steatosis, and apoptosis because of their influential effect on the activity of metabolic proteins like SOD, GSH, MDA, and catalase. The study emphasized the controlled usage TiO2 nanoparticles in daily activity with a concern for ecological and biomedical aspects.

B and T cell epitope-based peptides predicted from clumping factor protein of Staphylococcus aureus as vaccine targets.

Staphylococcus aureus infection is emerging as a global threat because of the highly debilitating nature of the associated disease's unprecedented magnitude of its spread and growing global resistance to antimicrobial medicines. Recently WHO has categorized these bacteria under the high global priority pathogen list and is one of the six nosocomial pathogens termed as ESKAPE pathogens which have emerged as a serious threat to public health worldwide. The development of a specific vaccine can stimulate an optimal antibody response, thus providing immunity against it. Therefore, in the present study efforts have been made to identify potential vaccine candidates from the Clumping factor surface proteins (ClfA and ClfB) of S. aureus. Employing the immunoinformatics approach, fourteen antigenic peptides including T-cell, B-cell epitopes were identified which were non-toxic, non-allergenic, high antigenicity, strong binding efficiency with commonly occurring MHC alleles. Consequently, a multi-epitope vaccine chimera was designed by connecting these epitopes with suitable linkers an adjuvant to enhance immunogenicity. Further, homology modeling and molecular docking were performed to construct the three-dimensional structure of the vaccine and study the interaction between the modeled structure and immune receptor (TLR-2) present on lymphocyte cells. Consequently, molecular dynamics simulation for 100 ns period confirmed the stability of the interaction and reliability of the structure for further analysis. Finally, codon optimization and in silico cloning were employed to ensure the successful expression of the vaccine candidate. As the targeted protein is highly antigenic and conserved, hence the designed novel vaccine construct holds potential against emerging multi-drug-resistant organisms.

Prevalence and multidrug resistance in Salmonella enterica Typhimurium: an overview in South East Asia.

Acute/chronic gastroenteritis is caused by a few serovars of Salmonella enterica. Among different serovars, S. enterica Typhimurium is a potent pathogen that contributes significantly to self-limiting diarrhea related mortality worldwide. With no successful vaccine in hand against this pathogen, antibiotics are used as for gold standard for treatment against Salmonella induced gastroenteritis. Indispensably, rise in multi drug resistance against Salmonella Typhimurium poses challenge to treatment options. South East Asia, with 11 different countries, stands 3rd as super region for global burden of Salmonella induced gastroenteritis. In this review, we made an attempt to discuss on prevalence and multidrug resistance in Salmonella Typhimurium in 11 countries of South East Asia-the issue that has not been seriously addressed so far. By thorough analysis of reported data, we found varying frequencies for prevalence of Salmonella Typhimurium as well as subtle evidences on resistance of this pathogen to multiple antibiotics in different countries. Vietnam ranked top in terms of reports for prevalence and antimicrobial resistance. However, in countries such as Brunei and Timor Leste, no study has been performed so far to track the frequency of incidence and drug resistance of this pathogen. Our review, the first of its kind, emphasizes that, although the pathogen was not found as dominant serovar in South East Asia in last 20 years unlike sub-Saharan Africa, it may be still considered as a major threat in this region due to available evidences for infection in humans as well as contamination in several animal and food sources. More importantly, the importance as a public threat in this subregion of Asia is also due to resistance of this pathogen to multiple antibiotics. South East Asian countries showing incidence and multi drug resistance of Salmonella enterica Typhimurium in human and non-human sources (1969-2020). -Drug resistant S. enterica Typhimurium.

Genome-based identification and comparative analysis of enzymes for carotenoid biosynthesis in microalgae.

Microalgae are potential feedstocks for the commercial production of carotenoids, however, the metabolic pathways for carotenoid biosynthesis across algal lineage are largely unexplored. This work is the first to provide a comprehensive survey of genes and enzymes associated with the less studied methylerythritol 4-phosphate/1-deoxy-D-xylulose 5-phosphate pathway as well as the carotenoid biosynthetic pathway in microalgae through bioinformatics and comparative genomics approach. Candidate genes/enzymes were subsequently analyzed across 22 microalgae species of lineages Chlorophyta, Rhodophyta, Heterokonta, Haptophyta, Cryptophyta, and known Arabidopsis homologs in order to study the evolutional divergence in terms of sequence-structure properties. A total of 403 enzymes playing a vital role in carotene, lutein, zeaxanthin, violaxanthin, canthaxanthin, and astaxanthin were unraveled. Of these, 85 were hypothetical proteins whose biological roles are not yet experimentally characterized. Putative functions to these hypothetical proteins were successfully assigned through a comprehensive investigation of the protein family, motifs, intrinsic physicochemical features, subcellular localization, pathway analysis, etc. Furthermore, these enzymes were categorized into major classes as per the conserved domain and gene ontology. Functional signature sequences were also identified which were observed conserved across microalgal genomes. Additionally, the structural modeling and active site architecture of three vital enzymes, DXR, PSY, and ZDS catalyzing the vital rate-limiting steps in Dunaliella salina were achieved. The enzymes were confirmed to be stereochemically reliable and stable as revealed during molecular dynamics simulation of 100 ns. The detailed functional information about individual vital enzymes will certainly help to design genetically modified algal strains with enhanced carotenoid contents.

Role of OB-Fold Protein YdeI in Stress Response and Virulence of Salmonella enterica Serovar Enteritidis.

An essential feature of the pathogenesis of the Salmonella enterica serovar Enteritidis wild type (WT) is its ability to survive under diverse microenvironmental stress conditions, such as encountering antimicrobial peptides (AMPs) or glucose and micronutrient starvation. These stress factors trigger virulence genes carried on Salmonella pathogenicity islands (SPIs) and determine the efficiency of enteric infection. Although the oligosaccharide/oligonucleotide binding-fold (OB-fold) family of proteins has been identified as an important stress response and virulence determinant, functional information on members of this family is currently limited. In this study, we decipher the role of YdeI, which belongs to OB-fold family of proteins, in stress response and virulence of S Enteritidis. When ydeI was deleted, the ΔydeI mutant showed reduced survival during exposure to AMPs or glucose and Mg2+ starvation stress compared to the WT. Green fluorescent protein (GFP) reporter and quantitative real-time PCR (qRT-PCR) assays showed ydeI was transcriptionally regulated by PhoP, which is a major regulator of stress and virulence. Furthermore, the ΔydeI mutant displayed ∼89% reduced invasion into HCT116 cells, ∼15-fold-reduced intramacrophage survival, and downregulation of several SPI-1 and SPI-2 genes encoding the type 3 secretion system apparatus and effector proteins. The mutant showed attenuated virulence compared to the WT, confirmed by its reduced bacterial counts in feces, mesenteric lymph node (mLN), spleen, and liver of C57BL/6 mice. qRT-PCR analyses of the ΔydeI mutant displayed differential expression of 45 PhoP-regulated genes, which were majorly involved in metabolism, transport, membrane remodeling, and drug resistance under different stress conditions. YdeI is, therefore, an important protein that modulates S Enteritidis virulence and adaptation to stress during infection.IMPORTANCES Enteritidis during its life cycle encounters diverse stress factors inside the host. These intracellular conditions allow activation of specialized secretion systems to cause infection. We report a conserved membrane protein, YdeI, and elucidate its role in protection against various intracellular stress conditions. A key aspect of the study of a pathogen's stress response mechanism is its clinical relevance during host-pathogen interaction. Bacterial adaptation to stress plays a vital role in evolution of a pathogen's resistance to therapeutic agents. Therefore, investigation of the role of YdeI is vital for understanding the molecular basis of regulation of Salmonella pathogenesis. In conclusion, our findings may contribute to finding potential targets to develop new intervention strategies for treatment and prevention of enteric diseases.

dEMBF v2.0: An Updated Database of Enzymes for Microalgal Biofuel Feedstock.

In light of increasing algal genomics data and knowledge of biosynthetic pathways responsible for biofuel production, an integrated resource for easy access to all information is essential to improve our understanding of algal lipid metabolism. Against this backdrop, dEMBF v2.0, a significantly updated and improved version of our database of microalgae lipid biosynthetic enzymes for biofuel production, has been developed. dEMBF v2.0 now contains a comprehensive annotation of 2018 sequences encoding 35 enzymes, an increase of over 7-fold as compared with the first version. Other improved features include an increase in species coverage to 32 algal genomes, analysis of additional metabolic pathways, expanded annotation thoroughly detailing sequence and structural features, including enzyme-ligand interactions, and integration of supporting experimental evidence to demonstrate the role of enzymes in increasing lipid content. Along with a complete redesign of the interface, the updated database provides several inbuilt tools and user-friendly functionalities for more interactive and dynamic visualization of data.

Selective in vivo molecular and cellular biocompatibility of black peppercorns by piperine-protein intrinsic atomic interaction with elicited oxidative stress and apoptosis in zebrafish eleuthero embryos.

Day to day consumption of black pepper raise concern about the detailed information about their medicinal, pharmaceutical values and knowledge about the biocompatibility with respect to ecosystem. This study investigates the in vivo selective molecular biocompatibility of its seed cover (SC) and seed core (SP) powder extract using embryonic zebrafish model. Gas chromatography mass spectrometry (GCMS) analysis of the extract prepared by grinding showed presence of different components with "piperine" as principle component. Biocompatibility analysis showed dose and time dependent selective effect of SC and SP with LC50 of 30.4 µg/ml and 35.6 µg/ml, respectively on survivability, hatching and heartbeat rate in embryonic zebrafish. Mechanistic investigation elucidated it as effect of accumulation and internalization of black pepper leading to their influence on structure and function of cellular proteins hatching enzyme (he1a), superoxide dismutase (sod1) and tumor protein (tp53) responsible for delayed hatching, oxidative stress induction and apoptosis. The study provided insight to selective biocompatibility of black pepper expedient to produce higher quality spices with respect to pharmaceutical, clinical and environmental aspects.

Biogenic Au@ZnO core-shell nanocomposites kill Staphylococcus aureus without provoking nuclear damage and cytotoxicity in mouse fibroblasts cells under hyperglycemic condition with enhanced wound healing proficiency.

The aim of the present study is focused on the synthesis of Au@ZnO core-shell nanocomposites, where zinc oxide is overlaid on biogenic gold nanoparticles obtained from Hibiscus Sabdariffa plant extract. Optical property of nanocomposites is investigated using UV-visible spectroscopy and crystal structure has been determined using X-ray crystallography (XRD) technique. The presence of functional groups on the surface of Au@ZnO core-shell nanocomposites has been observed by Fourier transforms infrared (FTIR) spectroscopy. Electron microscopy studies revealed the morphology of the above core-shell nanocomposites. The synthesized nanocomposite material has shown antimicrobial and anti-biofilm activity against Staphylococcus aureus and Methicillin Resistant Staphylococcus haemolyticus (MRSH). The microbes are notorious cross contaminant and are known to cause infection in open wounds. The possible antimicrobial mechanism of as synthesized nanomaterials has been investigated against Staphylococcus aureus and obtained data suggests that the antimicrobial activity could be due to release of reactive oxygen species (ROS). Present study has revealed that surface varnishing of biosynthesized gold nanoparticles through zinc oxide has improved its antibacterial proficiency against Staphylococcus aureus, whereas reducing its toxic effect towards mouse fibroblast cells under normal and hyperglycaemic condition. Further studies have been performed in mice model to understand the wound healing efficiency of Au@ZnO nanocomposites. The results obtained suggest the possible and effective use of as synthesized core shell nanocomposites in wound healing.

Ca2+-dependent Focal Exocytosis of Golgi-derived Vesicles Helps Phagocytic Uptake in Macrophages.

The role of Golgi apparatus during phagocytic uptake by macrophages has been ruled out in the past. Notably, all such reports were limited to Fcγ receptor-mediated phagocytosis. Here, we unravel a highly devolved mechanism for recruitment of Golgi-derived secretory vesicles during phagosome biogenesis, which was important for uptake of most cargos, except the IgG-coated ones. We report recruitment of mannosidase-II-positive Golgi-derived vesicles during uptake of diverse targets, including latex beads, Escherichia coli, Salmonella typhimurium, and Mycobacterium tuberculosis in human and mouse macrophages. The recruitment of mannosidase-II vesicles was an early event mediated by focal exocytosis and coincided with the recruitment of transferrin receptor, VAMP3, and dynamin-2. Brefeldin A treatment inhibited mannosidase-II recruitment and phagocytic uptake of serum-coated or -uncoated latex beads and E. coli However, consistent with previous studies, brefeldin A treatment did not affect uptake of IgG-coated latex beads. Mechanistically, recruitment of mannosidase-II vesicles during phagocytic uptake required Ca2+ from both extra- and intracellular sources apart from PI3K, microtubules, and dynamin-2. Extracellular Ca2+ via voltage-gated Ca2+ channels established a Ca2+-dependent local phosphatidylinositol 1,4,5-trisphosphate gradient, which guides the focal movement of Golgi-derived vesicles to the site of uptake. We confirmed Golgi-derived vesicles recruited during phagocytosis were secretory vesicles as their recruitment was sensitive to depletion of VAMP2 or NCS1, whereas recruitment of the recycling endosome marker VAMP3 was unaffected. Depletion of both VAMP2 and NCS1 individually resulted in the reduced uptake by macrophages. Together, the study provides a previously unprecedented role of Golgi-derived secretory vesicles in phagocytic uptake, the key innate defense function.

In Vivo Molecular Toxicity Profile of Dental Bioceramics in Embryonic Zebrafish ( Danio rerio).

The investigation of the biocompatibility of potential and commercially available dental material is a major challenge in dental science. This study demonstrates that the zebrafish model is a novel in vivo model for investigating the biocompatibility of dental materials. Two commercially available dental materials, mineral trioxide aggregate (MTA) and Biodentine, were assessed for their biocompatibility. The biocompatibility analysis was performed in embryonic zebrafish with the help of standard toxicity assays measuring essential parameters such as survivability and hatching. The mechanistic and comparative analysis of toxicity was performed by oxidative stress analysis by measuring ROS induction and apoptosis in zebrafish exposed to dental materials at different concentrations. The molecular investigation at the protein level was done by a computational approach using in silico molecular docking and pathway analysis. The toxicity analysis showed a significant reduction in hatching and survivability rates along with morphological malformations with an increase in the concentration of exposed materials. ROS and apoptosis assay results revealed a greater biocompatibility of Biodentine as compared to that of MTA which was concentration-dependent. In silico analysis showed the significant role of the tricalcium silicate-protein ( Sod1, tp53, RUNX2B) interaction in an exhibition of toxicity. The study provides a new vision and standard in dental material sciences for assessing the biocompatibility of potential novel and commercially available dental materials.

Quantitative Proteomic and Phosphoproteomic Analysis of H37Ra and H37Rv Strains of Mycobacterium tuberculosis.

Mycobacterium tuberculosis, the causative agent of tuberculosis, accounts for 1.5 million human deaths annually worldwide. Despite efforts to eradicate tuberculosis, it still remains a deadly disease. The two best characterized strains of M. tuberculosis, virulent H37Rv and avirulent H37Ra, provide a unique platform to investigate biochemical and signaling pathways associated with pathogenicity. To delineate the biomolecular dynamics that may account for pathogenicity and attenuation of virulence in M. tuberculosis, we compared the proteome and phosphoproteome profiles of H37Rv and H37Ra strains. Quantitative phosphoproteomic analysis was performed using high-resolution Fourier transform mass spectrometry. Analysis of exponential and stationary phases of these strains resulted in identification and quantitation of 2709 proteins along with 512 phosphorylation sites derived from 257 proteins. In addition to confirming the presence of previously described M. tuberculosis phosphorylated proteins, we identified 265 novel phosphorylation sites. Quantitative proteomic analysis revealed more than five-fold upregulation of proteins belonging to virulence associated type VII bacterial secretion system in H37Rv when compared to those in H37Ra. We also identified 84 proteins, which exhibited changes in phosphorylation levels between the virulent and avirulent strains. Bioinformatics analysis of the proteins altered in their level of expression or phosphorylation revealed enrichment of pathways involved in fatty acid biosynthesis and two-component regulatory system. Our data provides a resource for further exploration of functional differences at molecular level between H37Rv and H37Ra, which will ultimately explain the molecular underpinnings that determine virulence in tuberculosis.