Skip to Navigation Skip to Content Skip to Footer

Microbiology Logo Microbiology & Immunology
Te Tari Moromoroiti me te Ārai Mate

Associate Professor Keith Ireton

Research interests:

Medical microbiology and microbial pathogenesis, cellular microbiology

Current research:

My laboratory studies molecular mechanisms of virulence of the food-borne pathogens Listeria monocytogenes, Shigella flexneri, and enteropathogenic E. coli (EPEC). One ongoing project focuses on understanding the process by which Listeria induces its internalization into host human cells. Other projects examine how Listeria, Shigella, or EPEC spreads from infected human cells to surrounding healthy cells.



Ireton Lab 2023



PhD students:
Nicole Lee
Pasan Dahanayake

MSc student:
George Warren

BSc honours student:
Allie Strange

Post doctoral fellows:
Dr. Thilina Herath
Dr. Attika Rehman

Research Assistant:
Thiloma Liyanage

5th floor laboratory manager:
Dr. Antonella Gianfelice


Highly motivated graduate students interested in PhD or MSc studies are encouraged to contact Keith Ireton (  For information on admissions and scholarships visit:


Research projects:

  • Understanding how exploitation of the host process of exocytosis promotes internalization and cell-to-cell spread of Listeria monocytogenes
  • Elucidating the molecular mechanism of cell-to-cell-spread of Shigella flexneri
  • Identification of mechanisms controlling pedestal formation by EPEC



Health Research Council of NZ (project grant 22/296)

Marsden Fund, Royal Society of NZ (project grant 22-UOO-098)

University of Otago Research Committee



Recent publications

Ireton, K., Gyanwali, G.C., Herath, T.U.B., and Lee, N. 2023. Exploitation of the host exocyst complex by bacterial pathogens. Mol. Microbiol. In Press. Link to preprint.

Gyanwali, G.C., Herath, T.U.B., Gianfelice, A., and Ireton, K. 2022. Listeria monocytogenes co-opts the host exocyst complex to promote Internalin A-mediated entry. Infect. Immun. Link to abstract.

Ireton, K., Mortuza, R., Gyanwali, G.C., Gianfelice, A., and Hussain, M. 2021. Role of internalin proteins in pathogenesis of Listeria monocytogenes. Mol Microbiol. 116: 1407-1419. Link to abstract.

Herath, T.U.B., Roy, A., Gianfelice, A., and Ireton, K. 2021. Shigella flexneri subverts host polarized exocytosis to enhance cell-to-cell spread. Mol. Microbiol. 116: 1328-1346.  Link to abstract.

Dowd, G.C., Mortuza, R., and Ireton, K. 2021. Molecular mechanisms of intercellular dissemination of bacterial pathogens. Trends Microbiol. 29: 127-141. Link to abstract.

Dowd, G.C., Mortuza, R., Bhalla, M., Van Ngo, H., Li, Y., Rigano, L.A., and Ireton, K. 2020. Listeria monocytogenes exploits host cell exocytosis to promote cell-to-cell spread. Proc. Natl. Acad. Sci. USA.

Nakatani, Y.; Shimaki, Y., Dutta, D. Muench, S., Ireton, K., Cook, G., Jeuken, L. 2020. Unprecedented mode of action of phenothiazines as ionophores unravelled by an NDH-2 bioelectrochemical assay platform. J. Am. Chem. Soc. 142: 1311-1320. Link to abstract.

Saila, S., Gyanwali, G.C., Husain, M., Gianfelice, A., and Ireton, K. 2019. The host GTPase Arf1 and its effectors AP1 and PICK1 stimulate actin polymerization and exocytosis to promote entry of Listeria monocytogenes. Infect. Immun. 88:e00578-19. Link to abstract.

Bhalla, M., Van Ngo, H., Gyanwali, B., and Ireton, K. 2018. The host scaffolding protein Filamin A and the exocyst complex control exocytosis during InlB-mediated entry of Listeria monocytogenes. Infect. Immun. 87: e00689-18. Link to abstract.

Ireton, K. 2018. A helpful PEST for Listeriolysin O? Cell Host and Microbe. 23: 693-694. Link to article.

Ireton, K., Van Ngo, H., and Bhalla, M. 2017. Interaction of microbial pathogens with host exocytic pathways. Cellular Microbiology. 19: e12768. Link to abstract.

Van Ngo, H., Bhalla, M., Chen, D.Y., and Ireton, K. 2017. A role for host exocytosis in InlB-mediated internalization of Listeria monocytogenes. Cell. Microbiol. 2017:e12768. Link to abstract.

Bhalla, M., Law, D., Dowd, G.C., and Ireton, K. 2017. Host serine/threonine kinases mTOR and PKC-alpha promote inlB-mediated entry of Listeria monocytogenes. Infect. Immun. Jun 20;85: e00087-17. doi: 10.1128/IAI.00087-17. Link to article.

Ireton, K. 2016. Rickettsia evades a tense situation. Cell Host Microbe. 20: 549-550. Link to article.

Dowd, G.C., Bhalla, M., Kean, B., Thomas, R., and Ireton, K. 2016. Role of host type IA phosphoinositide 3-kinase pathway components in invasin-mediated internalization of Yersinia enterocolitica. 2016. Infect. Immun. 84: 1826-1841. Link to abstract.

Gianfelice, A., Le, P.H.B, Rigano, L.A., Saila, S., Dowd, G.C., McDivitt, T., Bhattacharya, H., Hong, W., Stagg, M., and Ireton, K. 2015. Host endoplasmic reticulum COPII proteins control cell-to-cell spread of the bacterial pathogen Listeria monocytogenes. Cell Microbiol. DOI: 10.1111/cmi.12409. Link to abstract.

Ireton, K., Rigano, L.A., and Dowd, G.C. Role of host GTPases in infection by Listeria monocytogenes. 2014.Cell. Microbiol. DOI: 10.1111/cmi.12324. EPub ahead of print. Link to abstract.

Ireton, K., Rigano, L.A., Polle, L., and Schubert, W.D. 2014. Molecular mechanism of protrusion formation during cell-to-cell spread of ListeriaFront. Cell. Infec. MicrobiolLink to abstract.

Rigano, L.A., Dowd, G.C., Wang, Y., and Ireton, K. 2014. Listeria monocytogenes antagonizes the human GTPase Cdc42 to promote bacterial spread. Cell. MicrobiolOnline early version accessed here.

Polle, L., Rigano, L.A., Julian, R., Ireton, K., and Schubert, W.D. 2014. Structural details of human Tuba recruitment by InlC of Listeria monocytogenes elucidate bacterial cell-cell spreading. Structure. 22: 304-314. Link to abstract.

Ireton, K. 2013. Molecular mechanisms of cell-cell spread of intracellular bacterial pathogens. Open Biology. 3: 130079. Link to abstract.

Leung, N., Gianfelice, A., Gray-Owen, S.D., and Ireton, K. 2013. Impact of the Listeria monocytogenes protein InlC on infection in  mice. Infect. Immun. 81: 1334-1240. Link to abstract.

Jiwani, S., Wang, Y., Dowd, G.C., Gianfelice, A., Pichestapong, P., Gavicherla, B., Vanbennekom, N., and Ireton, K. 2012. Identification of components of the host type IA PI 3-kinase pathway that promote internalization of Listeria monocytogenes. Infect. Immun. 80: 1252-1266. Link to abstract.

Ireton, K.  2010.  Anthrax toxins - roadblocks for exocytic trafficking.  Dev. Cell.  19:643-4. Link to abstract.

Gavicherla, B., Ritchey, L., Gianfelice, A., Kolokoltsov, A.A., Davey, R.A., and Ireton, K.  2010.  Critical role for the host GTPase activating protein ARAP2 in InIB-mediated entry of Listeria monocytogenes. Infect. Immun.  78:4532-41. Link to abstract.

Taylor, M., Navarro-Garcia, F., Huerta, J., Burress, H., Massey, S., Ireton, K., and Teter, K. 2010.  Hsp90 is required for transfer of the cholera toxin A1 subunit from the endoplasmic reticulum to the cytosol.  J. Biol. Chem. 285:31261-7. Link to abstract.

Rajabian, T., Gavicherla, B., Heisig, M., Muller-Altrock, S., Goebel, W., Gray-Owen, S.D., and Ireton, K.  2009.  The bacterial virulence factor InIC perturbs apical cell junctions and promotes cell-cell spread of Listeria.  2009.  Nat. Cell Biol. 11:1212-18. Link to abstract.

Goldoni, S., Humphries, A., Mystrom, A., Sattar, S., Owens, R.T., McQuillan, D.J., Ireton, K., and Iozzo, R.V.  2009.  Decorin is a novel antagonistic ligand of the Met receptor.  J. Cell Biol. 185:743-54. Link to abstract.

Gao, X., Lorinczi, M., Hill, K.S., Brooks, N.C., Dokainish, H., Ireton, K., and Elferink, L.A. 2009. Met receptor tyrosine kinase degradation is altered in response to the LRR fragment of the Listeriainvasion protein InlB. J. Biol. Chem. 278: 774-783. Link to abstract.

Selected older Publications 

Dokainish, H., Gavicherla, B., Shen, Y., and Ireton, K.  2007.  The carboxyl-terminal SH3 domain of the mammalian adaptor protein CrkII promotes internalization of Listeria monocytogenes through activation of host phosphoinositide 3-kinase. Cell. Microbiol. 9:2497-616. Link to abstract.

Ireton, K.  Entry of the bacterial pathogen Listeria monocytogenes into mammalian cells.  2007.  Cell. Microbiol. 9 1365-75. Link to abstract.

Basar, T., Shen, Y., and Ireton, K. 2005. Redundant roles for Met docking site tyrosines and the Gab1 pleckstrin homology domain in InlB-mediated entry of Listeria monocytogenes. Infec. Immun. 73: 2061-2074. Link to abstract.

Sun, H., Shen, Y., Dokainish, H., Holgado-Madruga, M., Wong, A., and Ireton, K. 2005. Host adaptor proteins Gab1 and CrkII promote InlB-dependent entry of Listeria monocytogenes. Cell. Microbiol. 7: 443-457. Link to abstract.

Shen, Y., Naujokas, M., Park, M., and Ireton, K. 2000. InlB-dependent internalization of Listeria is mediated by the Met receptor tyrosine kinase. Cell. 103: 501-510. Link to abstract.

PubMed link to all publications

Downloadable publications available at Research Gate


Sources of funding 

Health Research Council, project grant 17/082

University of Otago Research Committee 

Positions available

Former lab members

Tina McDivitt (former PhD student): President of Spindle consulting (Toronto, Canada)

Shahanawaz Jiwani (former PhD student): Associate director, Molecular Diagnostics Laboratory, National Cancer Institute, USA 

Manmeet Bhalla (former PhD student): Post-doctoral fellow, State University of New York- Buffalo, USA

Hoan Van Ngo (former PhD student): Post-doctoral fellow, London Institute of Tropical Medicine and Hygiene, UK

Susan Saila (former PhD student): Microbiologist, Mastoplex Ltd, Dunedin, NZ

Phuong Le (former MSc student): Pharmacist, NZ

Daria Law (former BBioMedSci honours student): Senior Scientist, Apis Assay Technologies Ltd, UK

Bernard Kean (former BBioMedSci honours student): Medical student, University of Otago

Hong Sun (former post-doctoral fellow): Senior Scientist, Sanofi Pasteur, Canada

Luciano Rigano (former post-doctoral fellow): Biosecurity NZ

Georgina Dowd (former post-doctoral fellow): Scientist, Plant and Food Research, NZ

Antonella Gianfelice (former post-doctoral fellow): Assistant Research Fellow, University of Otago, NZ