Korolik Group

Supervisors: Prof Victoria Korolik & Dr Christopher J Day

Molecular Microbiology

The natural habitat of campylobacters is the intestine of warm-blooded animals, and therefore chemotactic motility is an important mechanism involved in the colonisation and pathogenicity of this microorganism. Bacterial motility is subject to sensory control mechanisms that introduce a bias into the swimming direction of the organism towards beneficial environments and away from unfavourable conditions. Although chemotaxis has been demonstrated for Campylobacter the chemical substrates, mechanisms involved in the sensory control of motility and the role of chemotaxis in disease, are poorly understood. We, therefore, hypothesise that the chemosensory receptor proteins play a key role in chemotaxis and are involved in the pathogenicity of this organism as the first line of bacterial – host interaction and thus provide rational targets for the design of novel antimicrobial agents.

This project involves characterisation of interactions of the signaling domain of one of the chemoreceptors of C. jejuni, named Tlp1 with CheW and CheV chemotaxis proteins.  The major aim of this project is to identify which amino acids in the signaling domain of Tlp1 are responsible for binding with CheW and CheV though systematic site-specific mutagenesis followed by analysis of the mutated proteins using yeast 2-hybrid protein-protein interaction system.
This project will further the studies to elucidate the role of Tlp1 chemoreceptor in chemotaxis and pathogenicity of C. jejuni, which can potentially provide a tremendous insight into the mechanisms of chemotaxis of this organism.

Supervisors: Prof Victoria Korolik & Dr Bassam Elgamoudi

Molecular Microbiology

The natural habitat of campylobacters is the intestine of warm-blooded animals, and therefore chemotactic motility is an important mechanism involved in the colonisation and pathogenicity of this microorganism. Bacterial motility is subject to sensory control mechanisms that introduce a bias into the swimming direction of the organism towards beneficial environments and away from unfavourable conditions. Although chemotaxis has been demonstrated for Campylobacter the chemical substrates, mechanisms involved in the sensory control of motility and the role of chemotaxis in disease, are poorly understood. We, therefore, hypothesise that the chemosensory receptor proteins play a key role in chemotaxis and are involved in the pathogenicity of this organism as the first line of bacterial – host interaction and thus provide rational targets for the design of novel antimicrobial agents.

This project involves characterisation of interactions of one of the chemoreceptors of C. jejuni, named Tlp7 with environmental molecules. The major aim of this project is to identify which chemicals are responsible for triggering chemotactic responses governed by Tlp7.  This will be determined using site-specific mutagenesis followed by analysis of the wild type and mutated proteins using small molecule and glycan arrays, chemotaxis assays and mammalian cell culture.

This project will further the studies to elucidate the role of Tlp7 chemoreceptor in chemotaxis and pathogenicity of C. jejuni, which can potentially provide a tremendous insight into the mechanisms of chemotaxis of this organism.

Supervisors: Prof Victoria Korolik & Dr Bassam Elgamoudi

Molecular Microbiology

The natural habitat of campylobacters is the intestine of warm-blooded animals, and therefore chemotactic motility is an important mechanism involved in the colonisation and pathogenicity of this microorganism. Bacterial motility is subject to sensory control mechanisms that introduce a bias into the swimming direction of the organism towards beneficial environments and away from unfavourable conditions. Although chemotaxis has been demonstrated for Campylobacter the chemical substrates, mechanisms involved in the sensory control of motility and the role of chemotaxis in disease, are poorly understood. We, therefore, hypothesise that the chemosensory receptor proteins play a key role in chemotaxis and are involved in the pathogenicity of this organism as the first line of bacterial – host interaction and thus provide rational targets for the design of novel antimicrobial agents.

This project involves characterisation of interactions of the chemoreceptors of C. jejuni, named Tlps, with periplasmic ligand-binding proteins The major aim of this project is to identify how periplasmic ligand binding proteins induce directed bacterial motility to nutrients and host targets though small molecule arrays, chemotaxis assays, systematic mutagenesis followed by analysis of the mutated proteins using yeast 2-hybrid protein-protein interaction system, mammalian cell culture and animal models.

This project will further the studies to elucidate the role of chemosensors in in chemotaxis and pathogenicity of C. jejuni, which can potentially provide a tremendous insight into the mechanisms of chemotaxis of this organism.

Supervisors: Prof Victoria Korolik & Dr Bassam Elgamoudi

Molecular Microbiology

Biofilms and complex multi-species communities are a preferred manner by which bacteria exist within the host or grow on various surfaces. In this mode, the cells exude gelatinous exopolymeric substances that are mostly polysaccharides, proteins and DNA. Progressively, a structured biofilm matrix or a gel, consisting of cells and exuded elements, is formed in which cells are protected from physical trauma, immune clearance mechanisms, desiccation and antimicrobial agents. In nature, most biofilms are complex and are formed by many different microbes in a multi-species community. Campylobacter jejuni, a ubiquitous pathogen, is a known to be associated with complex gel and surface biofilms and is an ideal model for studies of naturally occurring multi-species biofilms. C. jejuni is recognised as one of the most important human food-borne pathogens to date and is the leading cause of acute human bacterial gastroenteritis worldwide. C. jejuni survives in foods, animal products and aquatic environments. We hypothesise that it does so by integration into complex microbial communities and biofilms. The formation of complex multi-species communities involving C. jejuni, and their role in transmission of infection, are poorly understood. We aim to use a comprehensive, biologically valid multidisciplinary approach to quantify the composition, both microbial and host-related, of naturally occurring complex communities involving C. jejuni. We will use transcriptome and mass spectroscopy analysis with wild type and mutated C. jejuni strains contained in chicken caeca and in laboratory created biofilms. This will allow us to understand how this pathogen integrates into complex microbial communities and biofilms, how to break the chain of transmission of C. jejuni from animals and animal food sources, how to reduce incidence of campylobacteriosis in human population, and ultimately, how to develop novel strategies for biological intervention in disease transmission to humans.