Cath Rees
Associate Professor in Microbiology, Faculty of Science
Contact
- workRoom B23 Food Sciences
Sutton Bonington Campus
Sutton Bonington
Leicestershire
LE12 5RD
UK - work0115 951 6167
- fax0115 951 6162
- cath.rees@nottingham.ac.uk
Expertise Summary
Focus of research is the application of molecular biology to fundamental research on micro-organisms of importance to the food industry. As a specialist in bacterial genetics and molecular biology I have focussed on understanding the adaptive response of micro-organisms to environmental conditions of relevance to the Food Industry, such as low temperature stress and osmotic stress. However the study of the physiology of a bacterial pathogen cannot be divorced from an understanding of its pathogenicity mechanisms and I have also focused on how environmental factors can influence the expression of virulence genes. Specifically I have tried to concentrate my research on the Gram-positive bacterium Listeria monocytogenes. Experience gained in the manipulation of this organism has also lead to collaborations with my colleagues working in other Gram-positive bacteria, such as Staphylococcus aureus. Current areas of interest are partial DNA methylation system which produces stable patterns of chromosomal DNA methylation much like those seen in eukaryotic DNA and relevance to pathogenicity; molecular analysis of growth and survival at low temperature, focussing on regulatory DNA binding proteins; interaction of virulence and motility gene regulatory networks.
Second area of expertise is in bacteriophage biology and genetics. Prior to my appointment as a lecturer I was involved in an industrially funded programme to genetically engineer phage as a rapid detection method for Listeria. This work culminated in the successful creation of such a phage, but the climate of suspicion which currently surrounds GM organisms means that this work will not be commercially developed. However these studies also lead to the patenting of a new method of bacterial detection using non-engineered phage called the Phage Amplification Assay. This project continues to develop and have recently developed new tests for the detection of Mycobacterium paratuberculosis, I have also been involved in three projects to investigate the use of phage as natural biocontrol agents for specific pathogens within the food processing environment, and latterly in live birds prior to slaughter. Thus my fundamental knowledge of phage biology and genetics has allowed me to contribute to more practically oriented research projects involving a diverse range of micro-organisms.
For last 18 months have been part of an interdisciplinary research project with Physics and Astronomy to use magnetic levitation as a model for 0g growth conditions. Expertise in bacterial physiology has lead to the design of experiments to investigate the effects of levitation on bacterial growth stimulation.
Research Summary
Trained as a bacterial molecular geneticist, my research interest lies in the areas of adaptive bacterial gene expression and biotechnology. The underlying link between these two is, on the one hand,… read more
Selected Publications
Current Research
Trained as a bacterial molecular geneticist, my research interest lies in the areas of adaptive bacterial gene expression and biotechnology. The underlying link between these two is, on the one hand, a study of patterns of gene expression in food borne pathogenic bacteria and, on the other, the application of bacterial gene expression systems for use in the applied microbiology field. Outlined below are some examples of research programmes which are currently being pursued. Environmental adaptation of Listeria monocytogenes The incidence of food borne listeriosis showed a marked increase in the last 10 years. This rise occurred in parallel with an increase in the production and distribution of processed chilled foods. The trend has been attributed to the ability of the causative agent, Listeria monocytogenes, to grow and proliferate at low temperatures which inhibit the growth of many food borne pathogens. Research now centres on several aspects of the physiology of this organism, for instance the factors that allow it to grow at low temperatures, environmental regulation of virulence and the regulation of motility and links with virulence (with Dr R E Sockett, Life Sciences Department). Evidence that the stress conditions prevailing in foods - which are designed to limit microbial growth - may in fact cause the bacteria to induce the expression of virulence genes, thereby making the few surviving cells intrinsically more pathogenic, emphasises the timely nature of this research (for a review see Rees et al., 1995, Int. J. Food Microbiol. 28:263-275). Production of bacteriophage lysins for bacterial detection Through a MAFF-funded project and links with collaborators in the Dairy Research Institute in Freising, Germany, we are currently developing the use of lysin proteins which specifically attack and lyse listerial cells. The ultimate goal is to produce a readily purified and stable recombinant protein which can be used in a variety of ways to either eradicate, or detect the presence of, this pathogen in food or clinical environments. The detection system under development utilises the wealth of expertise that exists in the Department in the detection and quantification of bioluminescence.