A5063360595- Monoclonal and Polyclonal Antibodies Research
- RNA and protein synthesis mechanisms
- Radiopharmaceutical Chemistry and Applications
- Salmonella and Campylobacter epidemiology
- Bacteriophages and microbial interactions
- Vibrio bacteria research studies
- Bacterial biofilms and quorum sensing
- Bacterial Genetics and Biotechnology
- Lung Cancer Treatments and Mutations
- Escherichia coli research studies
- Genomics and Phylogenetic Studies
- Antibiotic Resistance in Bacteria
- RNA Research and Splicing
- RNA modifications and cancer
- Computational Drug Discovery Methods
- Viral gastroenteritis research and epidemiology
- Cancer-related gene regulation
- Central Venous Catheters and Hemodialysis
- Yersinia bacterium, plague, ectoparasites research
- Microbial Community Ecology and Physiology
- Listeria monocytogenes in Food Safety
- Gut microbiota and health
- Nosocomial Infections in ICU
- CRISPR and Genetic Engineering
- Probiotics and Fermented Foods
University of Saskatchewan
2015-2024
Saskatchewan Health
2023
University of British Columbia
2022
University Research Co (United States)
2022
University of Arizona
2021
University of Calgary
2003-2011
Teagasc - The Irish Agriculture and Food Development Authority
2006
University of Victoria
1998-2003
Salmonella spp. are environmentally persistent pathogens that have served as one of the important models for understanding how bacteria adapt to stressful conditions. However, it remains poorly understood they survive extreme conditions encountered outside their hosts. Here we show rdar morphotype, a multicellular phenotype characterized by fimbria- and cellulose-mediated colony pattern formation, enhances resistance desiccation. When colonies were stored on plastic several months in absence...
In this study, we show that Salmonella produces an O-antigen capsule coregulated with the fimbria- and cellulose-associated extracellular matrix. Structural analysis of purified polysaccharides yielded predominantly a repeating oligosaccharide unit similar to enterica serovar Enteritidis lipopolysaccharide O antigen some modifications. Putative carbohydrate transport regulatory operons important for assembly translocation, designated yihU-yshA yihVW, were identified by screening random...
The type III secretion system (T3SS) is an important genetic determinant that mediates interactions between Gram-negative bacteria and their eukaryotic hosts. Our understanding of the T3SS continues to expand, yet availability new bacterial genomes prompts questions about its diversity, distribution evolution. Through a comprehensive survey ∼20 000 genomes, we identified 174 non-redundant T3SSs from 109 genera 5 phyla. Many are environmental strains have not been reported interact with...
ABSTRACT Lipopolysaccharide (LPS) O polysaccharide was identified as the principle factor impeding intercellular formation of intact thin aggregative fimbriae (Tafi) in Salmonella enterica serovar Enteritidis. The extracellular nucleation-precipitation assembly pathway for these organelles investigated by quantifying fimbrial between Δ agfA (AgfA recipient) and agfB donor) cells harboring mutations LPS ( galE ::Tn 10 ) and/or cellulose (Δ bcsA synthesis. Intercellular complementation could...
Salmonella thin aggregative fimbriae (Tafi; curli) are important in pathogenesis and biofilm formation; however, less is known of their structure morphogenesis. In the agfBAC Tafi operon, transcription role agfC have been elusive. this study, transcripts were detected using a sensitive reverse transcriptase technique. Native AgfC was not polyclonal antibodies generated against purified hexahistidine-tagged AgfC; trans expression revealed that localized to periplasm as mature form. An...
ABSTRACT The Salmonella rdar ( r ed, d ry, a nd ough) morphotype is an aggregative and resistant physiology that has been linked to survival in nutrient-limited environments. Growth of enterica serovar Typhimurium was analyzed variety nutrient-limiting conditions determine whether aggregation would occur at low cell densities the involved this process. resulting cultures consisted two populations cells, aggregated nonaggregated, with cells preferentially displaying gene expression. groups...
Bacteria can elaborate complex patterns of development that are dictated by temporally ordered gene expression, typically under the control a master regulatory pathway. For some processes, such as biofilm development, regulators initiate process have been identified but subsequent phenotypic changes stress tolerance do not seem to be these same regulators. A hallmark feature biofilms is growth within self-produced extracellular matrix. In this study we used metabolomics compare Salmonella...
ABSTRACT Establishing the risk of human infection is one goals public health. For bacterial pathogens, virulence and zoonotic potential can often be related to their host source. Escherichia coli bacteria are common contaminants water associated with recreation consumption, many strains pathogenic. In this study, we analyzed three promoter-containing intergenic regions from 284 diverse E. isolates in an attempt identify molecular signatures specific types. Promoter sequences controlling...
ABSTRACT Pathogenic bacteria often need to survive in the host and environment, it is not well understood how cells transition between these equally challenging situations. For human animal pathogen Salmonella enterica serovar Typhimurium, biofilm formation correlated with persistence outside a host, but connection virulence unknown. In this study, we analyzed multicellular-aggregate planktonic-cell subpopulations that coexist when S . Typhimurium grown under biofilm-inducing conditions....
Pathogenic Salmonella strains that cause gastroenteritis are able to colonize and replicate within the intestines of multiple host species. In general, these have retained an ability form rdar morphotype, a resistant biofilm physiology hypothesized be important for transmission. contrast, host-adapted or even host-restricted like enterica serovar Typhi, tend systemic infections lost morphotype. Here, we investigated morphotype CsgD-regulated formation in two non-typhoidal (NTS) caused...
Reactive arthritis, an autoimmune disorder, occurs following gastrointestinal infection with invasive enteric pathogens, such as Salmonella enterica. Curli, extracellular, bacterial amyloid cross beta-sheet structure can trigger inflammatory responses by stimulating pattern recognition receptors. Here we show that S. Typhimurium produces curli amyloids in the cecum and colon of mice after natural oral infection, both acute chronic models. Production was associated increase anti-dsDNA...
ABSTRACT The Salmonella rdar morphotype is a distinct, rough and dry colony morphology formed by the extracellular interaction of thin aggregative fimbriae (Tafi or curli), cellulose, other polysaccharides. Cells in colonies are more resistant to desiccation exogenous stresses, which hypothesized aid passage pathogenic spp. between hosts. Here we analyzed genetic phenotypic conservation throughout entire genus. was conserved 90% 80 isolates representing all 7 groups; however, frequency only...
Cases of foodborne disease caused by Salmonella are frequently associated with the consumption minimally processed produce. Bacterial cell surface components known to be important for attachment bacterial pathogens fresh The role these extracellular structures in plant walls has not been investigated detail. We flagella, fimbriae and cellulose on Typhimurium ATCC 14028 a range isogenic deletion mutants (ΔfliC fljB, ΔbcsA, ΔcsgA, ΔcsgA bcsA ΔcsgD) (BC)-based wall models [BC-Pectin (BCP),...
The colonization of catheters by microorganisms often precludes their long-term use, which can be a problem for human patients that have few body sites available new catheters. colonizing organisms form biofilms, and increasingly these are resistant to multiple antibiotics, making them difficult treat. In this article, we taken associated with biofilm formation in from two Canadian hospitals tested tetrasodium EDTA, antimicrobial catheter lock solution. Tetrasodium EDTA was effective at...
Curli, a major component of the bacterial biofilms in intestinal tract, activates pattern recognition receptors and triggers joint inflammation after infection with Salmonella enterica serovar Typhimurium. The factors that allow S. Typhimurium to disperse from invade epithelium establish successful during acute remain unknown. Here, we studied vitro vivo understand how inflammatory environment regulates switch between multicellular motile gut. We discovered nitrate generated by host is an...
Accumulating analyses of pro-oncogenic molecular mechanisms triggered a rapid development targeted cancer therapies. Although many these treatments produce impressive initial responses, eventual resistance onset is practically unavoidable. One the main approaches for preventing this refractory condition relies on implementation combination This includes dual-specificity reagents that affect both their targets with high level selectivity. Unfortunately, selection target combinations often...
Type III Secretion Systems (T3SSs) play important roles in the interaction between gram-negative bacteria and their hosts. T3SSs function by translocating a group of bacterial effector proteins into host cytoplasm. The details specific type secretion process are yet to be clarified. This research focused on comparing amino acid composition within N-terminal 100 acids from (T3S) signal sequences or non-T3S proteins, specifically whether each residue exerts constraint residues found adjacent...
Many Gram-negative bacteria infect hosts and cause diseases by translocating a variety of type III secreted effectors (T3SEs) into the host cell cytoplasm. However, despite dramatic increase in number available whole-genome sequences, it remains challenging for accurate prediction T3SEs. Traditional models have focused on atypical sequence features buried N-terminal peptides T3SEs, but unfortunately, these had high false-positive rates. In this research, we integrated promoter information...
The global poultry industry has grown to the extent that number of chickens now well exceeds humans on Earth. Escherichia coli infections in cause significant morbidity and economic losses for producers each year. We obtained 94 E. isolates from 12 colibacillosis outbreaks Saskatchewan farms screened them antimicrobial resistance biofilm formation. Fifty-six were broilers with confirmed colibacillosis, 38 healthy same flocks (cecal ). Resistance penicillins, tetracyclines, aminoglycosides...