A5033606022- Salmonella and Campylobacter epidemiology
- Bacteriophages and microbial interactions
- Probiotics and Fermented Foods
- Genomics and Phylogenetic Studies
- Yersinia bacterium, plague, ectoparasites research
- Viral gastroenteritis research and epidemiology
- Microbial Metabolites in Food Biotechnology
- Gut microbiota and health
- Microbial Community Ecology and Physiology
- Enzyme Production and Characterization
- Pharmacological Effects of Natural Compounds
- Bacterial Genetics and Biotechnology
- Vibrio bacteria research studies
- Heat shock proteins research
- Escherichia coli research studies
- Microbial infections and disease research
- Cancer Research and Treatments
- Aquaculture disease management and microbiota
- Bacterial biofilms and quorum sensing
- Plant-based Medicinal Research
- Glycosylation and Glycoproteins Research
- Clostridium difficile and Clostridium perfringens research
- RNA and protein synthesis mechanisms
- Enterobacteriaceae and Cronobacter Research
- Helicobacter pylori-related gastroenterology studies
Kingston University
2015-2024
Kingston University
2010-2021
University of London
2001-2014
London School of Hygiene & Tropical Medicine
2001-2014
University of Nottingham
1997-2009
Universidad de Londres
2000
University of Reading
1994-1999
St Bartholomew's Hospital
1998-1999
Institute of Immunological Engineering
1992-1997
State Research Center for Applied Microbiology and Biotechnology
1995
The Gram-negative bacterium Yersinia pestis is the causative agent of systemic invasive infectious disease classically referred to as plague, and has been responsible for three human pandemics: Justinian plague (sixth eighth centuries), Black Death (fourteenth nineteenth centuries) modern (nineteenth century present day). recent identification strains resistant multiple drugs potential use Y. an biological warfare mean that still poses a threat health. Here we report complete genome sequence...
Spent culture supernatants from both Aeromonas hydrophila and salmonicida activate a range of biosensors responsive to N-acylhomoserine lactones (AHLs). The genes for quorum sensing signal generator response regulator were cloned each species termed ahyRI asaRI, respectively. Protein sequence homology analysis places the gene products within growing family LuxRI homologs. ahyR asaR are transcribed divergently ahyI asaI, respectively, in species, downstream have been identified by DNA PCR...
Campylobacter jejuni is the leading cause of bacterial food-borne diarrhoeal disease throughout world, and yet still a poorly understood pathogen. Whole genome microarray comparisons 11 C. strains diverse origin identified genes in up to 30 NCTC 11168 loci ranging from 0.7 18.7 kb that are either absent or highly divergent these isolates. Many regions associated with biosynthesis surface structures including flagella, lipo-oligosaccharide, newly capsule. Other strain-variable known function...
Campylobacter jejuni , a Gram‐negative spiral bacterium, is the most common bacterial cause of acute human gastroenteritis and increasingly recognized for its association with serious post‐infection neurological complications Miller–Fisher Guillain–Barré syndromes. C. lipopolysaccharide (LPS) thought to be involved in pathogenesis both uncomplicated infection more sequelae, yet LPS remains poorly characterized. Current studies on suggest that all strains produce lipooligosaccharide (LOS),...
The major gastrointestinal pathogen Campylobacter jejuni is shown to exist as three forms of monospecies biofilm in liquid culture. It attaches a glass surface; an unattached aggregate (floc); and pellicle at the liquid–gas interface. resemble each other when examined by scanning electron microscopy. mode growth confers protection against environmental stress, microaerobic bacteria flocs surviving up 24 days ambient temperature atmosphere compared 12 survival planktonic bacteria. wild-type...
Summary We describe in this report the characterization of recently discovered N‐linked glycosylation locus human bacterial pathogen Campylobacter jejuni , first such system found a species from domain Bacteria. exploited ability to function Escherichia coli demonstrate through mutational and structural analyses that variant glycan structures can be transferred onto protein indicating relaxed specificity putative oligosaccharyltransferase PglB. Structural data derived these glycans allowed...
It has recently been shown that the enteropathogen Campylobacter jejuni an N -linked general p rotein gl ycosylation pathway (Pgl) modifies many of organism's proteins. To determine role glycosylation in C , authors studied pglH gene, which shows high similarity to a family sugar transferases. mutants were constructed strains 81116 and 11168H. Both be deficient their ability glycosylate number C. proteins, but lipooligosaccharide capsule unaffected. The had significantly reduced adhere...
The genome sequence of the human pathogen Campylobacter jejuni NCTC11168 has been determined recently, but studies on colonization and persistence in chickens have limited due to reports that this strain is a poor colonizer. Experimental were carried out with C. by using 2-week-old Light Sussex possessing an acquired natural gut flora. After inoculation, initially colonized intestine poorly. However, after 5 weeks we observed adaptation high-level colonization, which was maintained vitro...
We recently demonstrated that Campylobacter jejuni produces a capsular polysaccharide (CPS) is the major antigenic component of classical Penner serotyping system distinguishing into >60 groups. Although wide variety C. serotypes are suggestive structural differences in CPS, genetic mechanisms such unknown. In this study we sequenced biosynthetic cps regions, ranging size from 15 to 34 kb, selected strains HS:1, HS:19, HS:23, HS:36, HS:23/36 and HS:41 serotypes. Comparison determined...
Flagella-mediated motility is recognized to be one of the major factors contributing virulence in Campylobacter jejuni . Motility this bacterium known phase variable, although mechanism such variation remains unknown. C. genome sequencing revealed a number genes prone via slipped-strand mispairing mechanism. Many these are hypothetical and clustered regions involved formation three cell surface structures: capsular polysaccharide, lipooligosaccharide flagella. Among unknown function,...
N-acetyl neuraminic acid (NANA) is a common constituent of Campylobacter jejuni lipo-oligosaccharide (LOS). Such structures often mimic human gangliosides and are thought to be involved in the triggering Guillain-Barré syndrome (GBS) Miller-Fisher (MFS) following C. infection. Analysis NCTC 11168 genome sequence identified three putative NANA synthetase genes termed neuB1, neuB2 neuB3. The activity all neuB gene products was confirmed by complementation experiments an Escherichia coli...
Summary It was demonstrated recently that there is a system of general protein glycosylation in the human enteropathogen Campylobacter jejuni . To char‐ acterize such glycoproteins, we identified lectin, Soybean agglutinin (SBA), which binds to multiple C. proteins on Western blots. Binding lectin SBA disrupted by mutagenesis genes within previously locus. This used purify putative glycoproteins selectively and, after sodium dodecyl sulphate‐ polyacrylamide gel electrophoresis (SDS–PAGE),...
ABSTRACT Previously, we identified five genes (Cj1321 to Cj1326, of which Cj1325 and Cj1326 are a single gene) in the O-linked flagellin glycosylation island that highly prevalent Campylobacter jejuni isolates from chickens. We report mutagenesis, functional, structural data confirm this locus, Cj1324 particular, has significant contributory role colonization chickens by C. . A motile ΔCj1324 mutant with intact flagella was considerably less hydrophobic able autoagglutinate form biofilms...
We report that larvae of the wax moth (Galleria mellonella) are susceptible to infection with human enteropathogen Yersinia pseudotuberculosis at 37 degrees C. Confocal microscopy demonstrated in initial stages bacteria were taken up into haemocytes. To evaluate utility this model for screening Y. mutants we constructed and tested a superoxide dismutase C (sodC) mutant. This mutant showed increased susceptibility superoxide, key mechanism killing insect haemocytes mammalian phagocytes. It...
To investigate Yersinia pathogenicity and the evolutionary divergence of genus, effect pathogenic yersiniae on model organism Caenorhabditis elegans was studied. Three strains pestis , including a strain lacking pMT1, caused blockage death C. ; one strain, haemin storage ( hms ) locus, no effect. Similarly, 15 enterocolitica Strains pseudotuberculosis showed different levels pathogenicity. The majority (76 %) discernible effect; 5 % weak infection, 9·5 an intermediate severe infection. There...
ABSTRACT The genetic investigation of Campylobacter jejuni , an important gastrointestinal pathogen, has been hampered by the lack efficient system for introduction exogenous information, as commonly used vectors designed Escherichia coli and other bacteria cannot be maintained in cells. Additionally, gene expression requires presence species-specific promoters. In this study we exploited availability several conserved copies rRNA clusters insertion various genes into chromosome homologous...
In this study we investigated the commonality and biosynthesis of O-methyl phosphoramidate (MeOPN) group found on capsular polysaccharide (CPS) Campylobacter jejuni. High resolution magic angle spinning NMR spectroscopy was used as a rapid, high throughput means to examine multiple isolates, analyze cecal contents colonized chickens, screen library CPS mutants for presence MeOPN. Sixty eight percent C. jejuni strains were express MeOPN with prevalence among isolates from enteritis, Guillain...
Galleria mellonella (wax moth) larvae have elsewhere been shown to be susceptible pathogens such as Francisella tularensis, Burkholderia mallei, and Pseudomonas aeruginosa. We report that the are rapidly killed by Campylobacter jejuni at 37°C. Three strains of C. tested, 11168H (human diarrheal isolate), G1 Guillain-Barré syndrome 81–176 were equally effective killing G. larvae. A panel defined mutants 11168H, in known or putative virulence genes, showed different degrees attenuation mutant...
Helicobacter pylori is considered as the main risk factor in development of gastric cancer. In present study, we performed a detailed characterization probiotic properties and anti-H. activity previously isolated lactobacillus strain — Lactobacillus fermentum UCO-979C obtained from human gut. The tolerated pH 3.0; grew presence 2% bile salts; produced lactic acid hydrogen peroxide; aggregated saline solution; showed high hydrophobicity; adherence to glass; Caco-2 adenocarcinoma cells (AGS)...
Campylobacter jejuni is a major cause of bacterial gastroenteritis worldwide, and the capsular polysaccharide (CPS) this organism required for persistence disease. C. produces over 47 different structures, including unique O-methyl phosphoramidate (MeOPN) modification present on most isolates. Although MeOPN structure rare in nature it has structural similarity to some synthetic pesticides. In study, we have demonstrated, by whole genome comparisons high resolution magic angle spinning NMR,...
ABSTRACT We have recently demonstrated that most strains of Campylobacter jejuni produce capsular polysaccharide (CPS), which can be detected by immunoblotting with homologous Penner antisera on polyvinylidene difluoride membranes (A. V. Karlyshev, D. Linton, N. A. Gregson, J. Lastovica, and B. W. Wren, Mol. Microbiol. 35:529–541, 2000). In this report, we describe a universal rapid staining procedure using Alcian blue for C. CPS, does not rely the availability identifies CPS in untypeable...
ABSTRACT Yersinia pestis , the causative agent of plague, and enteropathogen pseudotuberculosis have nearly identical nucleotide similarity yet cause markedly different diseases. To investigate this conundrum to study pathogenicity, we developed a high-density oligonucleotide array-based modification signature-tagged mutagenesis (STM). Y. YPIII mutants constructed with tagged transposons were evaluated in murine yersiniosis infection model. The DNA tags amplified using biotinylated primers...