Molecular Bacteriology

Prof R K Poole - West Riding Chair in Microbiology

Career History

1967-1973: BSc (First Class Hons.), Department of Microbiology, University College Cardiff PhD, Department of Microbiology, University College Cardiff
1973-1974: Personal SRC Post-doctoral Research Fellowship, Department of Biochemistry, Medical Sciences Institute, The University, Dundee
1975-1985: Lecturer, Department of Microbiology, Queen Elizabeth College, London
(now King’s College London, KCL)

1984: DSc, University of Wales
1980-1981: Nuffield Foundation Science Research Fellow, Queen Elizabeth College, London
1984-1985: Royal Society Anglo-Australian Fellow, Australian National University, Canberra
1985: Fellow of the Institute of Biology
1986-1988: Reader in Microbiology, University of London
1988: Head of Department, Queen Elizabeth College
1988-1996: Personal Chair of Microbiology (KCL)
1990-1991: Royal Society-Leverhulme Trust Senior Research Fellow (KCL)
1993: Visiting Fellow, Australian National University, Canberra
1994: Fulbright Scholar, Cornell University
1997 – 2008: Director of Research, Biological Sciences, The University of Sheffield
1996-present: West Riding Chair of Microbiology, The University of Sheffield
2007: Fellow of the Royal Society of Chemistry

Main research interests and approaches

One of the most remarkable properties of bacteria is their ability to survive environmental stresses. Bacteria not only survive, but also flourish in, environments that contain toxic gases and other chemicals, are at extremes of temperature, salinity or that may have vanishingly low or exceedingly high levels of potential nutrients. Not only are these environments hostile, but they may also fluctuate rapidly, requiring fast responses in their occupants. Of particular interest to my laboratory is the ability of bacteria to thrive aerobically and anaerobically, and to resist the stresses caused by CO, and reactive oxidative and nitrosative chemical species. Three main themes underlie our present work.

Microbial respiration. We are trying to obtain a comprehensive understanding of how bacteria respire - aerobically and anaerobically - and how the diverse oxygen-reactive proteins of bacteria are involved in respiratory electron transfer, protection of bacteria from oxidative stress and the sensing of environmental and cellular oxygen levels. Problems of special interest at present are (i) a Systems Biology approach to understanding oxygen metabolism in E. coli (an international consortium involving Sheffield, Amsterdam, Magdeburg and Stuttgart) and (ii) haemoglobins in various bacteria, especially pathogens, that bind oxygen but also allow detoxification of nitric oxide (NO, see below).

Antibacterial activity of the respiratory poison carbon monoxide (CO) and molecules that release CO in physiologically tractable ways (CORMs). This project is a collaborative venture with Dr Roberto Motterlini (INSERM, Paris), Professor Robert Read (Royal Hallamshire Hospital, Sheffield) and Professor Brian Mann (Chemistry, Sheffield) and seeks to understand the balance between CO (derived from the host or by clinical intervention), pathogenic bacteria and the inflammatory response.

Microbial resistance to oxidative and nitrosative stresses. Of particular interest are those mechanisms that allow bacteria to survive the presence of NO - a simple diatomic radical, but which is immensely important throughout biology. NO is not only a physiologically critical signalling molecule involved in cardiovascular function, but also a potent product of the antibacterial activity involved in innate immunity. We have made major advances in understanding the function, regulation and properties of the flavohaemoglobin (Hmp) of Escherichia coli and Salmonella: the major (only?) function of this protein is to enzymically detoxify NO. We are also studying respiratory and NO metabolism in bacteria of clinical and pathogenic significance (especially Campylobacter, Mycobacterium and Salmonella) and this work is often done collaboratively with Professor Robert Read (Royal Hallamshire Hospital).

Work in my laboratory may be described as microbial physiology - the study of how bacteria and other microorganisms work. Although rooted in the tradition of bacterial growth and intermediary metabolism, microbial physiology now embraces molecular biology, genetics, biochemistry, and indeed any discipline that can shed light on bacterial function. Much of our experimental work is conducted with Escherichia coli, the pre-eminent ‘model’ organism with unrivalled ease of genetic and physiological manipulation. We are also work on its close relation, Salmonella (an intracellular pathogen and cause of enteritis), Neisseria meningitidis, Mycobacterium species and Campylobacter jejuni, the most common cause of food-borne disease.

The approaches used to study these problems range from molecular genetics, through microbial biochemistry and biophysics, to physiology and the properties of microbial populations in vitro and in vivo. Consequently, the tools we use are diverse; they include manipulations in vitro and in vivo of nucleic acids, bacterial molecular genetics (e.g. microarray technology, transposon-mediated and site-directed mutagenesis, gene and operon fusions), protein purification, immunochemical methods and characterisation using optical (dual- and multi-wavelength, stopped-flow, and rapid-scan spectrophotometry), fluorescence and magnetic spectroscopic tools.

Recent publications (2010-12)

SHEPHERD M., BARYNIN, V., LU, C., BERNHARDT, P. V., WU, G., YEH, S.-R., EGAWA, T., SEDELNIKOVA, S. E., RICE, D. W., WILSON, J. L. & POOLE , R. K. (2010) The single-domain globin from the pathogenic bacterium Campylobacter jejuni: resolution of the D-helix, influence of proximal hydrogen bonding on ligand binding, and peroxidase-like redox properties. J. Biol. Chem. 285, 12747-12754

McLEAN, S., BOWMAN, L. A. H. & POOLE, R. K. (2010) KatG from Salmonella Typhimurium is a peroxynitritase. FEBS Lett. 584, 1628-1632

SVENSSON, L., POLJAKOVIC, M., SÄVE, S., GILBERTHORPE, N., SCHÖN, T., STRID, S., CORKER, H., POOLE, R. K. & PERSSON, K. (2010) Role of flavohemoglobin in combating nitrosative stress in uropathogenic Escherichia coli – implications for urinary tract infection. Microb. Pathogen. 49, 59-66

SHEPHERD M., SANGUINETTI, G., COOK, G. M. & POOLE, R. K. (2010) Compensations for diminished terminal oxidase activity in Escherichia coli: cytochrome bd-II-mediated respiration and glutamate metabolism. J. Biol. Chem. 285, 18464-18472

McLEAN, S., BOWMAN, L. A. H., SANGUINETTI, G., READ, R. C. & POOLE, R. K. (2010) Peroxynitrite toxicity in Escherichia coli K12 elicits expression of oxidative stress responses and protein nitration and nitrosylation. J. Biol. Chem. 285, 20724-20731

THOMAS, M., SHEPHERD, M., POOLE, R. K., VAN VLIET, A. H. M., KELLY, D. J., & PEARSON, B. M. (2010) Two respiratory enzyme systems in Campylobacter jejuni NCTC 11168 contribute to growth on L-lactate. Environ. Microbiol. doi: 10.1111/j.1462-2920.2010.02307.x

POOLE, R. K. & SHEPHERD, M. (2010) Bacterial globins. In Encyclopedia of Biophysics (Ed. G. C. K. Roberts), Springer-European Biophysical Societies Association (EBSA). Submitted

SHEPHERD, M. & POOLE, R. K. (2010) Bacterial respiratory chains. In Encyclopedia of Biophysics (Ed. G. C. K. Roberts), Springer-European Biophysical Societies Association (EBSA). Submitted

McLEAN, S., BOWMAN, L. A. H. & POOLE, R. K. (2010) Peroxynitrite stress is exacerbated by flavohaemoglobin-derived oxidative stress in Salmonella Typhimurium and is relieved by nitric oxide. Microbiology 156, 35556-3565

SHEPHERD, M. & POOLE, R. K. (2010) Bacterial respiratory chains. In Encyclopedia of Biophysics (Ed. G. C. K. Roberts), Springer-European Biophysical Societies Association (EBSA). Submitted

SHEPHERD, M., BERNHARDT, P. V. & POOLE, R. K. (2011) Globin-mediated nitric oxide detoxification in the foodborne pathogenic bacterium Campylobacter jejuni proceeds via a dioxygenase or denitrosylase mechanism. Nitric Oxide 25, 229-233

TROTTER, E. W., ROLFE, M. D., HOUNSLOW, A. M., CRAVEN, C. J., WILLIAMSON, M. P., SANGUINETTI, G., POOLE, R. K. & GREEN, J. (2011) Reprogramming of Escherichia coli K-12 metabolism during the initial phase of transition from an anaerobic to a micro-aerobic environment. PLOS One 6, e25501

WILSON, J. L., JESSE, H. E., POOLE, R. K. & DAVIDGE, K. S. (2012) Antibacterial effects of carbon monoxide. Curr. Pharmaceut. Biotechnol., in the press

STRAZDINA, I., KRAVALE, Z., GALININA, N., RUTKIS, R., POOLE, R. K. & KALNENIEKS, U. (2012) Electron transport and oxidative stress in Zymomonas mobilis respiratory mutants. Arch. Microbiol. 194, 461-71

GRAHAM, A. I., SANGUINETTI, G., BRAMALL, N., McLEOD, C. W., & POOLE, R. K. (2012) Dynamics of a starvation-to-surfeit shift: a transcriptomic and modelling analysis of the bacterial response to zinc reveals transient behaviour of the Fur and SoxS regulons. Microbiology 158,

HOLCOMBE, M., ADRA, S., BICAK, M. and 18 others (2012) Modelling complex biological systems using an agent-based approach. Integrat. Biol. 4, 53-64

ROLFE, M. D., OCONE, A., STAPLETON, M. R., HALL, S., TROTTER, E. W., POOLE, R. K., SANGUINETTI, G & GREN, J. (2012) Systems analysis of transcription factor activities in environments with stable and dynamic oxygen concentrations. Open Biology 2, 120091

MCLEAN, S., MANN, B. E. & POOLE, R. K. (2012) Sulfite species enhance carbon monoxide release from CO-releasing molecules: implications for the deoxymyoglobin assay of activity. Anal. Biochem. 427, 36-40

LAVER, J. R., MCLEAN, S., BOWMAN, L. A. H., HARRISON, L. J., READ, R. C. & POOLE, R. K. (2012) Nitrosothiols in bacterial pathogens and pathogenesis. Antiox. Redox Signal. ahead of print. doi:10.1089/ars.2012.4767

AVILA-RAMIREZ, C., TINAJERO-TREJO, M., DAVIDGE, K. S., MONK, C. E., KELLY, D. J. & POOLE, R. K. (2012) Do globins in microaerophilic Campylobacter jejuni confer nitrosative stress tolerance under oxygen limitation? Antiox. Redox Signal. ahead of print. doi:10.1089/ars.2012.4750.