A5015950254- Escherichia coli research studies
- Gut microbiota and health
- Clostridium difficile and Clostridium perfringens research
- Bacteriophages and microbial interactions
- Antibiotic Resistance in Bacteria
- Bacterial Infections and Vaccines
- Vibrio bacteria research studies
- Inflammatory Bowel Disease
- Salmonella and Campylobacter epidemiology
- Microscopic Colitis
- Clinical Nutrition and Gastroenterology
- Pneumonia and Respiratory Infections
- Gastrointestinal motility and disorders
- RNA and protein synthesis mechanisms
- Bacterial Genetics and Biotechnology
- Polyamine Metabolism and Applications
- Genomics and Phylogenetic Studies
- Microbial Fuel Cells and Bioremediation
- Influenza Virus Research Studies
- Legume Nitrogen Fixing Symbiosis
- IL-33, ST2, and ILC Pathways
- Neonatal Respiratory Health Research
- Infant Nutrition and Health
- Inflammasome and immune disorders
- Metalloenzymes and iron-sulfur proteins
University of Alberta
2014-2025
Women and Children’s Health Research Institute
2023-2024
University of Calgary
2024
McMaster University
2017-2021
Alberta Glycomics Centre
2014
Outer membrane vesicles (OMV) are spherical membranous structures released from the outer (OM) of Gram-negative bacteria. OMV have been proposed to play several different roles during both pathogenesis and symbiosis. Despite fact that were described decades ago, their biogenesis is a poorly characterized process. Whether produced by an active mechanism or passive disintegration OM still matter controversy. Bacteroides fragilis thetaiotaomicron important members human microbiota. In this...
Hooking into antigen transfer Segmented filamentous bacteria (SFB) are anaerobic, spore-forming, clostridia-like organisms that important immune modulators in the mammalian gut. For some reason, SFB do not provoke inflammatory responses. Ladinsky et al. probed mechanistic basis of this soothing effect mice. attach tightly to intestinal epithelial cells via a hook-like structure. Bacterial material is extruded from hook and enters host cell by endocytosis. An protein called P3340 shuttled...
ABSTRACT Outer membrane vesicles (OMV) are proposed to mediate multiple functions during pathogenesis and symbiosis. However, the mechanisms responsible for OMV formation remain poorly understood. It has been shown in eukaryotic membranes that lipids with an inverted-cone shape favor of positive curvatures. Based on these studies, we formulated hypothesis lipid A deacylation might impose modifications result curvature outer (OM) subsequent formation. We tested effect remodeling biogenesis...
Salmonella Typhimurium (S. Tm) establishes systemic infection in susceptible hosts by evading the innate immune response and replicating within host phagocytes. Here, we sought to identify inhibitors of intracellular S. Tm replication conducting parallel chemical screens against growing macrophage-mimicking media macrophages. We several compounds that inhibit growth environment acidic, ion-limited media. report on antimicrobial activity psychoactive drug metergoline, which is specific Tm....
Abstract Adherent-invasive Escherichia coli (AIEC) are pathogenic bacteria frequently isolated from patients who have Crohn’s disease (CD). Despite the phenotypic differences between AIEC and commensal E. , comparative genomic approaches been unable to differentiate these two groups, making identification of key virulence factors a challenge. Here, we conduct high-resolution, in vivo genetic screen map genes required for intestinal colonization mice. In addition, use RNA-sequencing define...
Abstract Crohn’s disease is an inflammatory of the gastrointestinal tract characterized by aberrant response to microbial and environmental triggers. This includes altered microbiome dominated Enterobacteriaceae in particular adherent-invasive E. coli (AIEC). Clinical evidence implicates periods psychological stress exacerbation, disturbances gut might contribute pathogenic mechanism. Here we show that stress-exposed mice develop ileal dysbiosis, expansion Enterobacteriaceae. In AIEC...
Abstract Background Indole-3-propionic acid (IPA), a tryptophan metabolite produced by microbes, has demonstrated beneficial effects, including reversing dysbiosis, balancing bacterial populations, and reducing inflammation.1,2,3 However, the mechanisms behind these effects their impact on pathogenic microbes remain unclear. This study aimed to evaluate of IPA invasion in vitro, using potential pathobionts (Klebsiella variicola Klebsiella quasipneumoniae) isolated from non-inflamed sections...
Abstract Background Indole-3-propionic acid (IPA), a tryptophan metabolite produced by microbes, has demonstrated beneficial effects, including reversing dysbiosis, balancing bacterial populations, and reducing inflammation. However, the mechanisms behind these effects their impact on pathogenic microbes remain unclear. This study aimed to evaluate of IPA invasion in vitro, using potential pathobionts (Klebsiella variicola Klebsiella quasipneumoniae) isolated from non-inflamed sections colon...
Ralstonia solanacearum is one of the most lethal phytopathogens in world. Due to its broad host range, it can cause wilting disease many plant species economic interest. In this work, we identified O-oligosaccharyltransferase (O-OTase) responsible for protein O-glycosylation R. solanacearum. An analysis glycoproteome revealed that 20 proteins, including type IV pilins are substrates general glycosylation system. Although multiple glycan forms were identified, majority glycopeptides modified...
The peptidoglycan (PG) cell wall is an essential component of the envelope most bacteria. Biogenesis PG involves a lipid-linked disaccharide-pentapeptide intermediate called lipid II, which must be translocated across cytoplasmic membrane after it synthesized in inner leaflet this bilayer. Accordingly, has been demonstrated that MurJ, proposed II flippase Escherichia coli, required for biogenesis, and thereby viability. In contrast, MurJ not Bacillus subtilis because bacterium produces AmJ,...
The human gut is home to trillions of bacteria and provides the scaffold for one most complex microbial ecosystems in nature. Inflammatory bowel diseases, such as Crohn's disease, involve a compositional shift constituents this ecosystem with marked expansion Enterobacteriaceae, particularly Escherichia coli. Adherent-invasive E. coli (AIEC) strains are frequently isolated from biopsies patients, where their ability elicit inflammation suggests possible role pathology. Here, we consider...
Highlights•Horizontal acquisition of SsrB rewired the regulatory landscape S. enterica•SsrB divergently regulates flagellar motility in enterica and bongori•An evolved SsrB-binding region upstream flhDC drives repression promotes evasion host inflammasome during infectionSummaryBacterial two-component systems (TCS) couple detection niche-specific cues with adaptive gene expression to optimize fitness. In Salmonella Typhimurium (STM), SsrA-SsrB TCS virulence genes needed for survival within...
Crohn's disease (CD) is an inflammatory bowel with a complex etiology. Paradoxically, CD associated the use of antibiotics and increased abundance unusual phenotypic group Escherichia coli known as adherent-invasive E. (AIEC). However, impact on AIEC infection has not been well studied in controlled models infection. We infected mice before or after treatment variety different classes antibiotics. assessed levels feces tissues, localization by immunofluorescence microscopy, tissue pathology....
Abstract Background Recent studies indicated that Klebsiella (K) pneumoniae (isolated from the stool of IBD patients) and K. variicola mesenteric tissue Crohn disease have potential to induce inflammation in epithelial preadipocyte cells, exacerbating colitis murine models. We isolated these strains pediatric ulcerative (UC) patients' appendix (relevant UC pathogenesis given protective effects appendectomy) other non-inflamed colon sections. hypothesized isolates are invasive UC. These not...
In adults, liver-resident macrophages, or Kupffer cells (KCs), reside in the sinusoids and sterilize circulating blood by capturing rapidly flowing microbes. We developed quantitative intravital imaging of 1-day-old mice combined with transcriptomics, genetic manipulation, vivo infection assays to interrogate increased susceptibility newborns bloodstream infections. Whereas KCs were better at catching
Importance: Although highly effective in treating recurrent Clostridioides difficile infection (RCDI), the mechanisms of action fecal microbial transplantation (FMT) are not fully understood. Aim: The aim this study was to explore microbially derived products or pathways that could contribute therapeutic efficacy FMT. Methods: Stool shotgun metagenomic sequencing data from 18 FMT-treated RCDI patients at 4 points time were used for taxonomic and functional profiling their gut microbiome....
Abstract Background Recent studies indicated that Klebsiella (K) pneumoniae (isolated from the stool of IBD patients) and K. variicola mesenteric tissue Crohn disease have potential to induce inflammation in epithelial preadipocyte cells, exacerbating colitis murine models. Aims We isolated these strains pediatric ulcerative (UC) patients' appendix (relevant UC pathogenesis given protective effects appendectomy) other non-inflamed colon sections. hypothesized isolates are invasive UC. These...
Bacteria continue to develop resistance against antibiotics, including last-resort ones, reinforcing the urgent need for new antimicrobial strategies. Chemicals at infection sites in host often influence microbial virulence and antibiotic response; such interactions may offer targets. Polyamines are cationic small molecules bacteria encounter sites. They overproduced during infection, modulating immune responses. The ability of detoxify polyamines as by a spermine/spermidine...
The stringent response is an essential mechanism of metabolic reprogramming during environmental stress that mediated by the nucleotide alarmones guanosine tetraphosphate and pentaphosphate [(p)ppGpp]. In addition to physiological adaptations, (p)ppGpp also regulates virulence programs in pathogenic bacteria, including Salmonella enterica serovar Typhimurium. S Typhimurium a common cause acute gastroenteritis, but it may spread systemic tissues, resulting severe clinical outcomes. During...