A5042586066- Brucella: diagnosis, epidemiology, treatment
- Escherichia coli research studies
- Salmonella and Campylobacter epidemiology
- Bacteriophages and microbial interactions
- Burkholderia infections and melioidosis
- Galectins and Cancer Biology
- Mycobacterium research and diagnosis
- RNA and protein synthesis mechanisms
- Monoclonal and Polyclonal Antibodies Research
- Animal Diversity and Health Studies
- Animal Disease Management and Epidemiology
- Tuberculosis Research and Epidemiology
- Bacterial Genetics and Biotechnology
- Immunotherapy and Immune Responses
- Fungal Infections and Studies
- Vibrio bacteria research studies
- Bacillus and Francisella bacterial research
- Autophagy in Disease and Therapy
- Genomics and Phylogenetic Studies
- Viral gastroenteritis research and epidemiology
- Cancer Research and Treatments
- Endoplasmic Reticulum Stress and Disease
- Prion Diseases and Protein Misfolding
- Invertebrate Immune Response Mechanisms
- Ginseng Biological Effects and Applications
Texas A&M University
2015-2024
Bryan College
2022
Texas College
1990-2018
Texas A&M Health Science Center
2011
Arkansas Agricultural Experiment Station
1990-2008
University of California, Davis
2007
Kitasato University
2003
Wellborn Road Veterinary Medical Center
2003
Irish Equine Centre
2003
University of California, San Diego
1997
ABSTRACT Limited knowledge is available about the virulence mechanisms responsible for diarrheal disease caused by Salmonella typhimurium . To assess contribution to of determinants identified in models infection, we tested a collection S. mutants their ability cause enteritis calves. strains carrying mutations plasmid ( spvR ), pathogenicity island 2 (SPI-2) spiB or SPI-5 sopB ) mortality and acute diarrhea An rfaJ mutant, which defective lipopolysaccharide outer core biosynthesis, was...
ABSTRACT The genetic basis for chronic persistence of Brucella abortus in lymphoid organs mice, cows, and humans is currently unknown. We identified B. genes involved infection, by assessing the ability 178 signature-tagged mutants to establish maintain persistent infection mice. Each mutant was screened its colonize spleens mice at 2 8 weeks after inoculation. Comparison results from both time points two groups attenuated first group not recovered either or postinfection therefore defective...
ABSTRACT The genetic basis for the host adaptation of Salmonella serotypes is currently unknown. We have explored a new strategy to identify enterica serotype Typhimurium ( S. typhimurium ) genes involved in adaptation, by comparing virulence 260 randomly generated signature-tagged mutants during oral infection mice and calves. This screen identified four mutants, which were defective colonization only one two species tested. One mutant, displayed defect mice, was further characterized....
Bacteria of the genus Brucella are facultative intracellular parasites that cause brucellosis, a severe animal and human disease. Recently, group taxonomists merged brucellae with primarily free-living, phylogenetically related
ABSTRACT The O antigen of Brucella abortus has been described as a major virulence determinant based on the attenuated survival fortuitously isolated rough variants. However, lack genetic definition these mutants and naturally occurring species, ovis canis , confused interpretation. To better characterize role in survival, transposon mutagenesis was used to generate B. defective O-antigen presentation. Sequence analysis DNA flanking site Tn 5 insertion verify genes encoding...
The pathogenic role of the spv (Salmonella plasmid virulence) genes Salmonella dublin was determined in natural, bovine host. Since lack overt signs enteritis or enterocolitis due to infections mice has limited development a convenient experimental system study enteric disease, we used calves contribution S. dublin-induced salmonellosis. SpvR transcriptional regulator is required for expression spvABCD operon, constructed an spvR knockout mutation calf-virulent strain dublin. Calves were...
Brucellosis is characterized by abortion in ruminants and a protracted undulant fever humans, which often results severe pathological manifestations. Scant information exists about the molecular mechanisms employed Brucella abortus to combat host defenses or persist replicate within cells. Transposon (Tn5) mutagenesis of B. subsequent screening mutants for sensitivity killing murine macrophages mouse model led identification were severely attenuated intracellular survival. One group was...
Brucella abortus is a facultative, intracellular, pathogenic bacterium that replicates within macrophages and resists macrophage microbicidal mechanisms. To study gene expression to elucidate the defense mechanisms used by B. resist destruction macrophages, protein synthesis was examined pulse-labeling techniques during intracellular growth J774A.1, macrophage-like cell line. Prominent changes observed include increased of proteins with estimated molecular masses 62, 28, 24, 17 kDa. The...
Automated sequence analysis of a 410-bp region the axyR gene in 105 Mycobacterium tuberculosis complex isolates identified polymorphic nucleotide that differentiated bovis from other members. All 29 M. sequenced had an adenine residue at 285, whereas all 76 guanine residue. PCR-restriction fragment length polymorphism oxyR with restriction endonuclease AluI additional 255 widespread intercontinental sources confirmed and extended unique association position 285 isolates.
The facultative intracellular bacterial pathogen Brucella infects a wide range of warm-blooded land and marine vertebrates causes brucellosis. Currently, there are nine recognized species based on host preferences phenotypic differences. availability 10 different genomes consisting two chromosomes representing six the allowed for detailed comparison among themselves relatives in order Rhizobiales. Phylogenomic analysis ortholog families shows limited divergence but distinct radiations,...
Cryptococcus neoformans (Cn), the major causative agent of human fungal meningoencephalitis, replicates within phagolysosomes infected host cells. Despite more than a half-century investigation into host-Cn interactions, factors that mediate infection by this pathogen remain obscure. Here, we describe development system employs Drosophila S2 cells and RNA interference (RNAi) to define characterize Cn factors. The recapitulated salient aspects interactions with mammalian cells, including...
Brucella species are facultative intracellular bacterial pathogens that cause brucellosis, a global zoonosis of profound importance. Although recent studies have demonstrated spp. replicate within an compartment contains endoplasmic reticulum (ER) resident proteins, the molecular mechanisms by which pathogen secures this replicative niche remain obscure. Here, we address issue exploiting Drosophila S2 cells and RNA interference (RNAi) technology to develop genetically tractable system...
Brucella are highly infectious bacterial pathogens responsible for brucellosis, a frequent worldwide zoonosis. The genus has recently expanded from 6 to 11 species, all of which were associated with mammals; natural host range amphibians after some reports atypical strains frogs. Here we describe the first in depth phenotypic and genetic characterization isolated frog. Strain B13-0095 was Pac-Man frog (Ceratophyrus ornate) at veterinary hospital Texas initially misidentified as Ochrobactrum...
ABSTRACT Immunomagnetic bead separation coupled with beating and real-time PCR was found to be a very effective procedure for the isolation, separation, detection of Mycobacterium avium subsp. paratuberculosis from milk and/or fecal samples cattle American bison. Samples were spiked M. organisms, which bound immunomagnetic beads subsequently lysed by beating; then protein cellular contaminants removed phenol-chloroform-isopropanol extraction prior DNA precipitation. purified this sequence...
Penetration of the intestinal mucosa at areas Peyer's patches is an important first step for Salmonella typhimurium to produce lethal systemic disease in mice. However, mutations genes that are invasion result only moderately decreased virulence S. Here we report combining invA and lpfC, two necessary entry into patches, results a much stronger attenuation than inactivation either these alone. An lpfC mutant was 150-fold attenuated by oral route infection but fully virulent when intestine...
The cloning of the gene(s) encoding a 36-kilodalton (kDa) cell envelope protein Brucella abortus has been previously described (T. A. Ficht, S. W. Bearden, B. Sowa, and L. G. Adams, Infect, Immun. 56:2036-2046, 1988). In an attempt to define nature duplication at this locus we have sequenced 3,500 base pairs genomic DNA encompassing region. represented two similar open reading frames which shared more than 85% homology nucleotide level but differed primarily because absence 108 nucleotides...
The Brucella abortus virB operon, encoding a type IV secretion system (T4SS), is required for intracellular replication and persistent infection in the mouse model. products of first two genes virB1 virB2, are predicted to be localized at bacterial surface, where they could potentially interact with host cells. Studies date have focused on characterization transposon mutations these genes, which expected exert polar effects downstream operon. In order determine whether VirB1 VirB2 function...