A5075730341- Gut microbiota and health
- Probiotics and Fermented Foods
- Bacterial biofilms and quorum sensing
- Redox biology and oxidative stress
- Clostridium difficile and Clostridium perfringens research
- Digestive system and related health
- Cystic Fibrosis Research Advances
- Oral microbiology and periodontitis research
- Bacterial Identification and Susceptibility Testing
- Streptococcal Infections and Treatments
- Corrosion Behavior and Inhibition
- Neutropenia and Cancer Infections
- Endoplasmic Reticulum Stress and Disease
- Inflammatory Bowel Disease
- Epigenetics and DNA Methylation
- Vitamin C and Antioxidants Research
- Diphtheria, Corynebacterium, and Tetanus
- Respiratory viral infections research
- Eating Disorders and Behaviors
- Ginseng Biological Effects and Applications
- Enterobacteriaceae and Cronobacter Research
- Genomics, phytochemicals, and oxidative stress
- Neonatal and Maternal Infections
- Microbial Community Ecology and Physiology
- Hematopoietic Stem Cell Transplantation
University of Victoria
2023-2025
Duke University
2017-2023
Duke University Hospital
2017-2020
Duke Medical Center
2017-2020
Dalhousie University
2013-2019
Izaak Walton Killam Health Centre
2013-2019
Lakehead University
2006-2010
The mucophilic anaerobic bacterium Akkermansia muciniphila is a prominent member of the gastrointestinal (GI) microbiota and only known species Verrucomicrobia phylum in mammalian gut. A high prevalence A. adult humans associated with leanness lower risk for development obesity diabetes. Four distinct phylogenetic groups have been described, but little about their relative abundance or how they impact human metabolic health. In this study, we isolated characterized 71 new strains from cohort...
Not all patients with cancer and severe neutropenia develop fever, the fecal microbiome may play a role. In single-center study of undergoing hematopoietic cell transplant ( n = 119), was characterized at onset neutropenia. A total 63 (53%) developed subsequent their displayed increased relative abundances Akkermansia muciniphila , species mucin-degrading bacteria P 0.006, corrected for multiple comparisons). Two therapies that induce neutropenia, irradiation melphalan, similarly expanded A....
Abstract The human gut microbiome within the gastrointestinal tract continuously adapts to variations in diet, medications, and host physiology. A central strategy for genetic adaptation is epigenetic phase variation (ePV) mediated by bacterial DNA methylation, which can regulate gene expression, enhance clonal heterogeneity, enable a single strain exhibit variable phenotypic states. Genome-wide site-specific ePV have been well characterized pathogens’ antigenic virulence factor production....
are common members of the human gastrointestinal microbiota. The prevalence these mucophilic bacteria, especially
Streptococcus gordonii is a commensal inhabitant of human oral biofilms. Previously, we identified an enzyme called SdbA that played important role in biofilm formation by S. gordonii. thiol-disulfide oxidoreductase catalyzes disulfide bonds secreted proteins. Surprisingly, inactivation results enhanced formation. In this study investigated the basis for ΔsdbA mutant. The revealed was mediated interaction between CiaRH and ComDE two-component signalling systems. Although it did not affect...
The inflammatory bowel diseases (IBD) occur in genetically susceptible individuals who mount inappropriate immune responses to their microbiota leading chronic intestinal inflammation. Whereas IBD clinical presentation is well described, how interactions between and host genotype impact early subclinical stages of the disease remains unclear. transcription factor hepatocyte nuclear 4 alpha (HNF4A) has been associated with human IBD, deletion Hnf4a epithelial cells (IECs) mice (Hnf4aΔIEC)...
Recently, we identified a novel disulfide oxidoreductase, SdbA, in the oral bacterium Streptococcus gordonii. Disulfide oxidoreductases form bonds nascent proteins using CXXC catalytic motif. Typically, N-terminal cysteine interacts with substrates, whereas C-terminal is buried and only reacts first of In this study, investigated SdbA C(86) P(87) D(88) C(89) vitro, single variants at N or position (SdbAC86P SdbAC89A ) were active but displayed different susceptibility to oxidation, was prone...
Biofilm samples collected from inside and outside the press former sections of paper machines in a Northwestern Ontario mill for period 2 years were characterized microbiologically electrochemically. Bacterial community profiling was done using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) selected bacterial isolates identified 16S rDNA analysis. The showed presence Proteobacteria, Firmicutes, Actinobacteria. Sphingomonas sp. found to be most common species,...
730 Background: ICIs are effective in mRCC, but one pertinent clinical need is to identify predictive biomarkers for response. The PD-1 receptor has been implicated regulating gastrointestinal commensal bacteria, with varied immune interactions, thereby impacting response ICIs. We evaluated bacterial taxa and ICI outcomes mRCC pts. Methods: Fecal samples from 22 pts were collected at baseline, week (wk)-4 on ICI, upon disease progression. Pts grouped as responders (R, complete or partial...
Streptococcus gordonii is a commensal inhabitant of the human oral cavity. To maintain its presence as major component biofilms, S. secretes inhibitory molecules such hydrogen peroxide and bacteriocins to inhibit competitors. produces two nonmodified (i.e., Sth1 Sth2) that are regulated by Com two-component regulatory system, which also regulates genetic competence. Previously we found thiol-disulfide oxidoreductase SdbA was required for bacteriocin activity; however, role in signaling not...
We previously identified a novel thiol-disulfide oxidoreductase, SdbA, in Streptococcus gordonii that formed disulfide bonds substrate proteins and played role multiple phenotypes. In this study, we used mutational, phenotypic, biochemical approaches to identify characterize the redox partners of SdbA. Unexpectedly, results showed SdbA has partners, forming complex oxidative protein-folding pathway. The primary maintain its active site an oxidized state are surface-exposed thioredoxin family...
Abstract Akkermansia muciniphila, a prominent member of the gastrointestinal tract (GI) microbiota, uses mucins as sole source carbon and nitrogen. A. muciniphila is considered next-generation probiotic because its abundance in humans positively correlates with protection from metabolic syndrome obesity. However, intractable to genetic analysis thus molecular mechanisms underlying metabolism mucin, colonization GI tract, impact on host physiology are poorly understood. Here, we developed...
Development of the inflammatory bowel diseases (IBD) has been linked to altered homeostatic relationships between intestine and microbiota it harbors. However early preclinical stages IBD remain poorly understood, especially with respect host-microbiota interactions. The nuclear receptor transcription factor Hepatocyte 4 alpha (HNF4A) important roles in intestinal epithelial cell (IEC) physiology, our recent studies zebrafish mice revealed that HNF4A activity IEC is suppressed by microbiota....