Blizard Institute - Barts and The London

Dr Olivier Marchès, PhD


Non-Clinical Lecturer in Bacteriology

Telephone: 020 7882 2425


I obtained my PhD in September 2003 from the University Paul Sabatier in Toulouse ( France ) working on molecular and cellular basis of pathogenic Escherichia coli virulence in the team of Dr Eric Oswald (Laboratoire Interactions Hotes-Agents Pathogènes (IHAP)). Then I was awarded a Marie Curie fellowship to conduct post-doctoral research in Pr Gad Frankel's lab at the Imperial College where I have carried on my studies on pathogenic E. coli from December 2003 to September 2007. Since October 2007, I have joined the Centre for Immunology and Infectious Disease within the Blizard Institute, where I have been appointed as a Non-Clinical Lecturer in Bacteriology.


MSc Clinical Microbiology: Molecular biology, microbial pathogenesis and the host immune response – module organizer Bacterial Pathogenicity (lectures and workshops)

Intercalated BSc in Infection and Immunity: module Biology of Bacteria (lectures)

MBBS: PBL facilitator – SSC tutor

Topics for PhD supervision:

  • Type 3 secretion system bacterial pathogens 
  • Escherichia coli pathogens (EPEC and EHEC) 
  • T3SS effectors and manipulation of host cell defences


Research Interests:

Enteropathogenic (EPEC) and enterohaemorrhagic (EHEC) Escherichia coli are important causes of acute gastroenteritis in humans. EPEC is a frequent cause of infantile diarrhoea in the developing world while EHEC causes a wide spectrum of illnesses ranging from mild diarrhoea to severe diseases, such as haemorrhagic colitis and haemolytic uraemic syndrome (HUS). My main research interest is to decipher the molecular cross-talk established between the EPEC or EHEC bacteria and their host with a long term aim being to identify new tracks to follow for development of therapeutics or control strategies for infections . A key element in EPEC and EHEC pathogenic strategy is their use of a type III secretion system to inject virulence proteins called effectors directly into host eukaryotic cells, proteins which subvert normal cellular functions. My research interest is to study the function of the effectors injected into the host tissues by pathogenic E. coli and the cellular pathways they subvert with a focus on the effectors used by the bacteria to manipulate mucosal immunity.

Recent and ongoing research projects:

  • Mode of action of NFkappaB inhibition by the T3SS effector NleE
  • Importance of GAP junction protein connexin 26 in bacterial infection (PhD project C. Simpson)


Vossenkämper A, Marchès O, Fairclough PD, Warnes G, Stagg AJ, Lindsay JO, Evans PC, Luong le A, Croft NM, Naik S, Frankel G, MacDonald TT. Inhibition of NF-kappaB signaling in human dendritic cells by the enteropathogenic Escherichia coli effector protein NleE. J Immunol 2010, 185, 4118-4127.

Vossenkämper A, MacDonald TT and Marchès O. Always one step ahead: How pathogenic bacteria use the type III secretion system to manipulate the intestinal mucosal immune system. J Inflamm (Lond) 2011 May 3;8(1):11

Arbeloa, A., Oates, C.V., Marchès, O., Hartland, E.L. & Frankel, G. Enteropathogenic and enterohemorrhagic Escherichia coli type III secretion effector EspV induces radical morphological changes in eukaryotic cells. Infect Immun 2011, 2079, 1067-1076.

Hemrajani C, Berger CN, Robinson SK,  Marchès O, Mousnier A, Frankel G. NleH effectors interact with Bax inhibitor-1 to block apoptosis during enteropathogenic Escherichia coli infection. Proc. Natl. Acad. Sci. USA 2010 Feb 16;107(7):3129-34.

View all Olivier Marchès's Research Publications at: