A5055827609- Nanoparticles: synthesis and applications
- Gut microbiota and health
- Tuberculosis Research and Epidemiology
- Monoclonal and Polyclonal Antibodies Research
- Heavy Metal Exposure and Toxicity
- Viral gastroenteritis research and epidemiology
- Salmonella and Campylobacter epidemiology
- Antibiotic Resistance in Bacteria
- Biochemical and Molecular Research
- HIV Research and Treatment
- Protein purification and stability
- Computational Drug Discovery Methods
- Arsenic contamination and mitigation
- Barrier Structure and Function Studies
- Antimicrobial Peptides and Activities
- Enzyme Structure and Function
- RNA Interference and Gene Delivery
- Graphene and Nanomaterials Applications
- Muscle Physiology and Disorders
- Biochemical Analysis and Sensing Techniques
- RNA and protein synthesis mechanisms
- Pneumocystis jirovecii pneumonia detection and treatment
- Pharmaceutical and Antibiotic Environmental Impacts
- Advanced Drug Delivery Systems
- Bacterial Genetics and Biotechnology
United States Food and Drug Administration
2016-2025
National Center for Toxicological Research
2016-2025
Food and Drug Administration
2020
University of Arkansas for Medical Sciences
2013-2018
Czech Academy of Sciences, Institute of Microbiology
2014
Texas College
2013
Texas A&M University
2000-2011
Mitchell Institute
2003-2006
Lawrence Livermore National Laboratory
2005
All India Institute of Medical Sciences
1996-1999
Silver nanoparticles (AgNP) are widely used for their antibacterial properties. Incorporation of AgNP into food-related products and health supplements represents a potential route oral exposure to AgNP; however, the effects such on gastrointestinal system mostly unknown. This study evaluated changes in populations intestinal-microbiota intestinal-mucosal gene expression Sprague-Dawley rats (both male female) that were gavaged orally with discrete sizes (10, 75 110 nm) silver acetate. Doses...
The antimicrobial activity of silver nanoparticles (AgNP) has led to interest in their use consumer products such as food contact materials, utensils, and storage containers. Incorporation these materials into items intended for processing suggests that could result gastrointestinal exposure AgNP, should the migrate from product. health impact AgNP is unknown, especially effects related intestinal epithelial permeability barrier function. This study examined different sizes (10, 20, 75 110...
Silver nanoparticles (AgNPs) as antibacterial agents are incorporated in many consumer products, while the use antiviral is an ongoing area of research. We evaluated properties AgNPs variable sizes (10, 75, and 110 nm) doses (25, 50, 100 μg/mL) at different contact time points against feline calicivirus (FCV), a surrogate for norovirus.Antiviral effects were determined by comparing infectivity FCV, appearance cytopathic (CPEs), integrity viral capsid protein suspension treated with untreated...
Intestinal microbiota composition and gut-associated immune response can contribute to the toxicity of arsenic. We investigated potential short-term arsenic exposure on gut microbiome composition, intestinal status, microbial resistance gene, metabolic profiles in adult developmental stages CD-1 mice. The arsenite [As(III)] was determined for two life stages: (i) animals at 24 or 48 h after single gavage (0.05 mg/kg body weight [b.w.] [low dose], 0.1 b.w. [medium 0.2 [high dose]) repeated 1...
Salmonella enterica serovar Heidelberg (S. Heidelberg) can cause foodborne illness in humans following the consumption of contaminated meat and poultry products. Recent studies from our laboratory have demonstrated that certain S. isolated food-animal sources harbor multiple transmissible plasmids with genes encode antimicrobial resistance, virulence a VirB4/D4 type-IV secretion system. This study examines potential role these bacterial uptake survival intestinal epithelial cells...
Atherosclerosis related cardiovascular diseases continue to be the primary cause of mortality in developed countries. The elevated level low density lipoprotein (LDL) is generally considered driver atherosclerosis, but recent years have seen a shift this perception that vascular plaque buildup mainly caused by oxidized LDL (ox-LDL) rather than native-LDL. scavenger receptor LOX-1 found endothelial cells binds and internalizes ox-LDL which leads initiation formation arteries. Using virtual...
The Mycobacterium tuberculosis lysAgene encodes the enzyme meso-diaminopimelate decarboxylase (DAPDC), a pyridoxal-5′-phosphate (PLP)-dependent enzyme. catalyzes final step in lysine biosynthetic pathway converting meso-diaminopimelic acid (DAP) tol-lysine. lysA gene of M. H37Rv has been established as essential for bacterial survival immunocompromised mice, demonstrating thatde novo biosynthesis is vivo viability. Drugs targeted against DAPDC could be efficient anti-tuberculosis drugs, and...
S-adenosylhomocysteine hydrolase (SAHH) is a ubiquitous enzyme that plays central role in methylation-based processes by maintaining the intracellular balance between (SAH) and S-adenosylmethionine. We report first prokaryotic crystal structure of SAHH, from Mycobacterium tuberculosis (Mtb), complex with adenosine (ADO) nicotinamide adenine dinucleotide. Structures complexes three inhibitors are also reported: 3'-keto aristeromycin (ARI), 2-fluoroadenosine, 3-deazaadenosine. The ARI reported...
Silver ions from silver nanoparticles (AgNP) or AgNPs themselves itself that are ingested consumer health care products indirectly absorbed food contact material can interact with the gastrointestinal tract (GIT). The permeability of GIT is strictly regulated to maintain barrier function and proper nutrient absorption. single layer intestinal epithelium adheres communicates actively neighboring cells extracellular matrix through different cell junctions. In current study, we hypothesized...
Salmonella enterica serovar Enteritidis is a leading cause of salmonellosis throughout the world and most commonly associated with consumption contaminated poultry egg products. has enhanced ability to colonize persist in extraintestinal sites within chickens. In this study, 54 isolates from human patients (n=28), retail chicken (n=9), broiler farms production facilities (n=8) were characterized by antimicrobial susceptibility testing, plasmid analysis, genetic relatedness using XbaI AvrII...
Abstract Nanomaterial synthesis and handling in a non‐sterile environment can result the final product becoming contaminated with bacterial endotoxin or lipopolysaccharides (LPB). During toxicological testing, effects caused by endotoxin‐contaminated nanomaterials be misinterpreted end‐point analysis (such as cytotoxicity immune responses) could erroneous conclusions. The objective of this study was twofold: (i) to test different carbon‐based (CBNs) [pristine graphene multi‐wall carbon...
Aloe leaf or purified aloin products possess numerous therapeutic and pharmaceutical properties. It is widely used as ingredients in a variety of food, cosmetic products. Animal studies have shown that consumption aloe cause intestinal goblet cell hyperplasia, malignancy. Here, we tested antibacterial effects aloin, against commensal microbiota. Minimum inhibitory concentration for several human bacterial species (Gram-positive Gram-negative) ranged from 1 to 4 mg/ml. Metabolism indicated...
The mitochondrial genome of kinetoplastids, including species Trypanosoma and Leishmania , is an unprecedented DNA structure catenated maxicircles minicircles. Maxicircles represent the typical encoding components respiratory complexes ribosomes. However, most mRNA sequences are cryptic, their maturation requires a unique U insertion/deletion RNA editing. Minicircles encode hundreds small guide RNAs (gRNAs) that partially anneal with unedited mRNAs direct extensive brucei gRNAs transcribed...
Consumer products manufactured with antimicrobial silver nanoparticles (AgNPs) may affect the gastrointestinal (GI) system. The human GI-tract is complex and there are physiological anatomical differences between animal models that limit comparisons species. Thus, assessment of AgNP toxicity on require tools allow for examination subtle changes in inflammatory markers indicators epithelial perturbation. Fresh tissues were excised from male female subjects to evaluate effects AgNPs GI-system....
PKS11 is one of three type III polyketide synthases (PKSs) identified in Mycobacterium tuberculosis. Although many PKSs M. tuberculosis have been implicated producing complex cell wall glycolipids, the biological function unknown. has previously proposed to synthesize alkylpyrones from fatty acid substrates. We solved crystal structure and found overall fold be similar other PKSs. a deep hydrophobic tunnel proximal active site Cys-138 accommodate observed electron density this co-purified...
Cytolethal distending toxin B (cdtB) is a conserved virulence factor in Salmonella enterica serovar Typhi. Here we report the presence and functionality of cdtB some nontyphoidal (NTS) serovars, including Javiana (cdtB+wt S. Javiana), isolated from imported food. To understand role NTS deletion mutant (cdtB(-)ΔS. Javiana) was constructed. Macrophages were infected with cdtB+wt (wild type), cdtB(-)Δ (mutant), cdtB-negative (S. Typhimurium). Cytotoxic activity transcription level genes...
COVID-19, the illness caused by SARS-CoV-2 virus, is now a worldwide pandemic with mortality in hundreds of thousands as infections continue to increase. Containing spread this viral infection and decreasing rate major challenge. Identifying appropriate antigenic epitopes from proteins very important task for vaccine production development diagnostic kits antibody therapy. A novel epitope would be specific virus can distinguish common cold viruses. In study two approaches are employed...
The bacterial leucine-responsive regulatory protein (Lrp) is a global transcriptional regulator that controls the expression of many genes during starvation and transition to stationary phase. Mycobacterium tuberculosis gene Rv3291c encodes 150-amino acid (designated here as Mtb LrpA) with homology Escherichia coli Lrp. crystal structure native form LrpA was solved at 2.1 A. shows an N-terminal DNA-binding domain helix-turn-helix (HTH) motif, C-terminal domain. In comparison complex E. AsnC...