A5065308776- Bacterial Genetics and Biotechnology
- Bacteriophages and microbial interactions
- Bacterial biofilms and quorum sensing
- Antibiotic Resistance in Bacteria
- Genomics and Phylogenetic Studies
- RNA and protein synthesis mechanisms
- Time Series Analysis and Forecasting
- Anomaly Detection Techniques and Applications
- Glycosylation and Glycoproteins Research
- Pain Management and Placebo Effect
- Fault Detection and Control Systems
- Pain Mechanisms and Treatments
- Pneumonia and Respiratory Infections
- Family Support in Illness
- Carbohydrate Chemistry and Synthesis
- Lipid Membrane Structure and Behavior
- Maternal Mental Health During Pregnancy and Postpartum
- Acupuncture Treatment Research Studies
- Microbial infections and disease research
- Computational Physics and Python Applications
- Vibrio bacteria research studies
- Bacterial Identification and Susceptibility Testing
- Family Caregiving in Mental Illness
- Musculoskeletal pain and rehabilitation
University of Toronto
2018-2025
Brown University
2023-2024
Providence College
2024
Canada Research Chairs
2018
University of Guelph
2010-2016
Lipopolysccharide (LPS) is an integral component of the Pseudomonas aeruginosa cell envelope, occupying outer leaflet membrane in this Gram-negative opportunistic pathogen. It important for bacterium-host interactions and has been shown to be a major virulence factor organism. Structurally, P. LPS composed three domains, namely, lipid A, core oligosaccharide, distal O antigen (O-Ag). Most strains produce two distinct forms O-Ag, one homopolymer D-rhamnose that common polysaccharide (CPA,...
The International Pseudomonas aeruginosa Consortium is sequencing over 1000 genomes and building an analysis pipeline for the study of genome evolution, antibiotic resistance virulence genes. Metadata, including genomic phenotypic data each isolate collection, are available through Database (http://ipcd.ibis.ulaval.ca/). Here, we present our strategy results that emerged from first 389 genomes. With as yet unmatched resolution, confirm P. strains can be divided into three major groups...
ABSTRACT Accurate typing methods are required for efficient infection control. The emergence of whole-genome sequencing (WGS) technologies has enabled the development genome-based applicable routine and surveillance bacterial pathogens. In this study, we developed Pseudomonas aeruginosa serotyper (PAst) program, which in silico serotyping P. isolates using WGS data. PAst been made publically available as a web service aptly facilitates high-throughput analysis. program overcomes critical...
Abstract Bacteria have evolved diverse antiviral defence mechanisms to protect themselves against phage infection. Phages integrated into bacterial chromosomes, known as prophages, also encode defences that the hosts in which they reside. Here, we identify a type of anti-phage interferes with virion assembly pathway invading phages. The protein mediates this defence, call Tab (for ‘Tail blocker’), is constitutively expressed from Pseudomonas aeruginosa prophage. allows replication cycle...
Biosynthesis of B-band lipopolysaccharide (LPS) in Pseudomonas aeruginosa follows the Wzy-dependent pathway, requiring integral inner membrane proteins Wzx (O-antigen [O-Ag] flippase), Wzy (O-Ag polymerase), and WaaL ligase). For an important first step deciphering mechanisms LPS assembly, we set out to map topology these proteins. Random targeted 3'wzx, wzy, waaL truncations were fused a phoA-lacZalpha dual reporter capable displaying both alkaline phosphatase beta-galactosidase activity....
Environmental and clinical isolates of the bacterium Pseudomonas aeruginosa frequently contain viruses known as prophages. These prophages can alter virulence their bacterial hosts through expression nonessential genes “morons.” In this study, we identified morons in a group phages characterized effects on behaviors. We found that many confer selective advantages for host, some which correlate with increased virulence. This work highlights symbiotic relationship between bacteria illustrates...
ABSTRACT The O-specific antigen (OSA) in Pseudomonas aeruginosa lipopolysaccharide is highly varied by sugar identity, side chains, and bond between O-repeats. These differences classified P. into 20 distinct serotypes. In the past few decades, O12 has emerged as predominant serotype clinical settings outbreaks. isolates exhibit high levels of resistance to various classes antibiotics. Here, we explore how OSA biosynthesis gene clusters evolve population investigating association...
Heteropolymeric B-band lipopolysaccharide in Pseudomonas aeruginosa PAO1 is synthesized via the so-called Wzy-dependent pathway, requiring a functional Wzy for polymerization of O-antigen repeat units periplasm. an integral inner membrane protein which detailed topology has been mapped recent investigation (Islam, S. T., Taylor, V. L., Qi, M., and Lam, J. (2010) mBio 1, e00189-10), revealing two principal periplasmic loops (PL), PL3 PL5, each containing RX(10)G motif. Despite considerable...
ABSTRACT Phages have been shown to use diverse strategies commandeer bacterial host cell metabolism during infection. However, for many of the physiological changes in bacteria infection, it is often unclear if they are part a response infection or actively driven by phage itself. Here, we identify two proteins that promote efficient replication reprogramming amino acid metabolism. These proteins, Eht1 and Eht2, expressed early cycle increase levels key acids arginine-derived polyamine...
Summary Heteropolymeric B‐band O‐antigen (O‐Ag) biosynthesis in Pseudomonas aeruginosa PAO1 follows the Wzy‐dependent pathway, beginning with translocation of undecaprenyl pyrophosphate‐linked anionic O‐Ag subunits (O units) from inner to outer leaflets membrane (IM). This is mediated by integral IM flippase Wzx. Through experimentally based and unbiased topological mapping, our group previously observed that Wzx possesses many charged aromatic amino acid residues within its 12 transmembrane...
Quorum sensing, a bacterial signaling system that coordinates group behaviors as function of cell density, plays an important role in regulating viral (phage) defense mechanisms bacteria. The opportunistic pathogen Pseudomonas aeruginosa is model for the study quorum sensing. P. also frequently infected by Pf prophages integrate into host chromosome. Upon induction, phages suppress sensing systems; however, physiological relevance and mechanism suppression are unknown. Here, we identify...
Lysogenic bacteriophage D3 causes seroconversion of Pseudomonas aeruginosa PAO1 from serotype O5 to O16 by inverting the linkage between O-specific antigen (OSA) repeat units α β. The OSA are polymerized Wzy modal lengths regulated Wzz1 and Wzz2. A key component machinery is inhibitor α-polymerase (Iap) peptide, which able solely suppress α-linked long-chain production in P. PAO1. To establish target specificity Iap for Wzyα, changes phenotypes were examined via Western immunoblotting wzz1...
Summary In microbial communities, viruses compete for host cells to infect, and thus evolved diverse ways inhibit their competitors. One mechanism is Superinfection exclusion (Sie), whereby a virus that has established an infection prevents secondary infection. We identified Pseudomonas prophage Sie protein alters pilus dynamics through the assembly chaperone, PilZ. This protein, known as Zip Pil Z i nteracting p rotein, does not abrogate activity, but fine tunes it, providing strong phage...
Pseudomonas aeruginosa is a Gram-negative bacterium that produces highly varied lipopolysaccharide (LPS) structures. The O antigen (O-Ag) in the LPS synthesized through Wzx/Wzy-dependent pathway where lipid-linked O-Ag repeats are polymerized by Wzy. Horizontal-gene transfer has been associated with diversity. present on surface of serotypes O5 and O16, differ intra-molecular bonds, α β, respectively; latter arose from action three genes serotype converting unit acquired bacteriophage D3,...
Quorum sensing, a bacterial signaling system that coordinates group behaviors as function of cell density, plays an important role in regulating viral (phage) defense mechanisms bacteria. The opportunistic pathogen
Pain perception and its modulation are fundamental to human learning adaptive behavior. This study investigated the hypothesis that pain is tied pain's function. Thirty-one participants performed a threat conditioning task where certain cues were associated with possibility of receiving painful electric shock. The signaled potential or safety regularly changed, requiring continually establish new associations. Using computational models, we quantified participants' expectations prediction...
The arms race between bacteria and phages led to the evolution of a wide range anti-phage defences, several which are controlled by host cell quorum sensing. In this work we characterize novel sensing anti-activator protein, known as anti-quorum protein 1 (Aqs1), found in Pseudomonas phage DMS3. We show that Aqs1 inhibits LasR, master regulator sensing, present X-ray crystal structure Aqs1-LasR complex. 69-residue also PilB, type IV pilus assembly ATPase protein. This study highlights...
Real world signal acquisition through sensors, is at the heart of modern digital revolution. However, almost every systems are contaminated with noise and outliers. Precise detection, curation data an essential step to reveal true-nature uncorrupted observations. With exploding volumes sources, there a critical need for robust but easy-to-operate, low-latency, generic yet highly customizable, outlier detection tool, easily accessible, adaptable diverse types sources. Existing methods often...
Real world signal acquisition through sensors, is at the heart of modern digital revolution. However, almost every systems are contaminated with noise and outliers. Precise detection, curation data an essential step to reveal true-nature uncorrupted observations. With exploding volumes sources, there a critical need for robust but easy-to-operate, low-latency, generic yet highly customizable, outlier detection tool, easily accessible, adaptable diverse types sources. Existing methods often...
Abstract Pain perception and its modulation are fundamental to human learning adaptive behavior. This study investigated the hypothesis that pain is tied pain’s function. Thirty-one participants performed a threat conditioning task where certain cues were associated with possibility of receiving painful electric shock. The signalled potential or safety regularly changed, requiring continually establish new associations. Using computational models, we quantified participants’ expectations...