A5008093410- Vibrio bacteria research studies
- Bacterial Genetics and Biotechnology
- Bacterial biofilms and quorum sensing
- Antibiotic Resistance in Bacteria
- Escherichia coli research studies
- Yersinia bacterium, plague, ectoparasites research
- Streptococcal Infections and Treatments
- Enzyme Structure and Function
- Bacteriophages and microbial interactions
- Glycosylation and Glycoproteins Research
- Clostridium difficile and Clostridium perfringens research
- Oral microbiology and periodontitis research
- Neonatal and Maternal Infections
- Probiotics and Fermented Foods
- RNA and protein synthesis mechanisms
- Amino Acid Enzymes and Metabolism
- Lipid Membrane Structure and Behavior
- Immune Response and Inflammation
- Toxin Mechanisms and Immunotoxins
- Infective Endocarditis Diagnosis and Management
- Catalytic Cross-Coupling Reactions
- Cancer Research and Treatments
- Cystic Fibrosis Research Advances
- Protein Tyrosine Phosphatases
- Polysaccharides and Plant Cell Walls
McMaster University
2017-2025
Discovery Centre
2020-2022
University of Toronto
2009-2020
Hospital for Sick Children
2009-2020
University of Washington
2014-2017
Seattle University
2015-2017
Queen's University
2012
Canada Research Chairs
2011-2012
University of Guelph
2008-2009
University of Wisconsin–Madison
1983
Extracellular polysaccharides comprise a major component of the biofilm matrix. Many species that are adept at formation have capacity to produce multiple types polysaccharides. Pseudomonas aeruginosa produces least three extracellular polysaccharides, alginate, Pel and Psl, been implicated in development. Non-mucoid strains can use either or Psl as primary matrix structural polysaccharide. In this study, we evaluated range clinical environmental P.aeruginosa isolates for their dependence on...
The human gut microbiome is a dynamic and densely populated microbial community that can provide important benefits to its host. Cooperation competition for nutrients among constituents only partially explain composition interpersonal variation. Notably, certain human-associated Bacteroidetes--one of two major phyla in the gut--also encode machinery contact-dependent interbacterial antagonism, but impact within communities remains unknown. Here we report prominent symbionts persist through...
Summary Bacterial secretion systems often employ molecular chaperones to recognize and facilitate export of their substrates. Recent work demonstrated that a secreted component the type VI system ( T 6 SS ), haemolysin co‐regulated protein Hcp binds directly effectors, enhancing stability in bacterial cytoplasm. Herein, we describe quantitative cellular proteomics screen for S substrates exploits this chaperone‐like quality . Application approach island I ‐encoded H 1‐ ) P seudomonas...
The Firmicutes are a phylum of bacteria that dominate numerous polymicrobial habitats importance to human health and industry. Although these communities often densely colonized, broadly distributed contact-dependent mechanism interbacterial antagonism utilized by has not been elucidated. Here we show proteins belonging the LXG polymorphic toxin family present in Streptococcus intermedius mediate cell contact- Esx secretion pathway-dependent growth inhibition diverse Firmicute species....
The perception and response to cellular death is an important aspect of multicellular eukaryotic life. For example, damage-associated molecular patterns activate inflammatory cascade that leads removal debris promotion healing. We demonstrate lysis Pseudomonas aeruginosa cells triggers a program in the remaining population confers fitness interspecies co-culture. find this program, termed P. antagonism (PARA), involves rapid deployment antibacterial factors mediated by Gac/Rsm global...
High cellular concentrations of bis-(3',5')-cyclic dimeric guanosine mono-phosphate (c-di-GMP) regulate a diverse range phenotypes in bacteria including biofilm development. The opportunistic pathogen Pseudomonas aeruginosa produces the PEL polysaccharide to form at air-liquid interface standing cultures. Among proteins required for production, PelD has been identified as membrane-bound c-di-GMP-specific receptor. In this work, we present x-ray crystal structure soluble cytoplasmic region...
The type VI secretion system (T6SS) is crucial in interbacterial competition and a virulence determinant of many Gram-negative bacteria. Several T6SS effectors are covalently fused to secreted structural components such as the VgrG spike for delivery into target cells. In Pseudomonas aeruginosa, VgrG2b effector was previously proposed mediate bacterial internalization eukaryotic this work, we find that C-terminal domain (VgrG2bC-ter) elicits toxicity periplasm, counteracted by cognate...
The Pel polysaccharide serves as an intercellular adhesin for the formation and maintenance of biofilms in opportunistic pathogen Pseudomonas aeruginosa. biosynthesis requires products a seven-gene operon, pelA-pelG, all which are necessary Pel-dependent biofilm Pel-related phenotypes. One genes, pelA, encodes protein with predicted deacetylase domain. In this work, role putative domain production was examined. We first established that purified recombinant PelA hydrolyzed pseudosubstrate...
The bacterial type VI secretion system (T6SS) mediates antagonistic cell–cell interactions between competing Gram-negative bacteria. In plant-beneficial bacteria, this pathway has been shown to suppress the growth of pathogens; however, identification and mode action T6SS effector proteins that mediate protective effect remain poorly defined. Here, we identify two previously uncharacterized effectors required for interbacterial antagonism by plant commensal bacterium Pseudomonas protegens....
Type VII secretion systems are membrane-embedded nanomachines used by Gram-positive bacteria to export effector proteins from the cytoplasm extracellular environment. Many of these effectors polymorphic toxins comprised an N-terminal Leu-x-Gly (LXG) domain unknown function and a C-terminal toxin that inhibits growth bacterial competitors. In recent work, it was shown LXG require two cognate Lap for T7SS-dependent export. Here, we present 2.6 Å structure TelA opportunistic pathogen
Pseudomonas aeruginosa is the predominant pathogen associated with chronic lung infection among cystic fibrosis patients. During colonization of lung, P. converts to a mucoid phenotype characterized by overproduction exopolysaccharide alginate. Secretion newly synthesized alginate across outer membrane believed occur through protein AlgE. Here we report 2.3 Å crystal structure AlgE, which reveals monomeric 18-stranded β-barrel highly electropositive pore constriction formed an arginine-rich...
The type VI secretion system (T6SS) is a widespread protein export apparatus found in Gram-negative bacteria. majority of T6SSs deliver toxic effector proteins into competitor Yet, the structure, function, and activation many these effectors remains poorly understood. Here, we present structures T6SS RhsA from Pseudomonas protegens its cognate spike protein, VgrG1, at 3.3 Å resolution. reveal that rearrangement hotspot (Rhs) repeats assemble closed anticlockwise β-barrel spiral similar to...