Department of Microbiology and Immunology

Hélène Marquis

Dr. MarquisProfessor of Microbiology

Cornell University College of Veterinary Medicine
C4 183 Veterinary Medical Center
Phone: 607-253-3273

DVM (University of Montreal)
PhD (Texas A&M University)


Dr. Marquis is a professor of Microbiology and Immunology. She received a doctorate degree in Veterinary Medicine from the University of Montréal in Canada and was awarded a Ph.D. in Veterinary Microbiology from Texas A&M University for her studies on the outer membrane proteins of Brucella spp. with Dr. Thomas Ficht. She was a postdoctoral fellow in the laboratory of Dr. Daniel Portnoy at the University of Pennsylvania, working on the pathogenesis of Listeria monocytogenes. In 1997, she assumed a position of assistant professor in the Department of Microbiology at the University of Colorado School of Medicine. She moved to Cornell University in July 2001.


Research Interests

The Marquis lab is interested in the pathogenesis of bacterial diseases affecting mammalian and aquatic animals. We are presently working on two research projects:

Role of pili in colonization of equine respiratory epithelium by Streptococcus equi ssp. equi.  One of the major hallmarks of a bacterial pathogen is its ability to attach to host cell surface receptors or extracellular matrix proteins in the initial steps of infection.  In collaboration with Professor Julia Felippe and research scientist Ute Schwab of the Department of Clinical Sciences at Cornell University, we are testing the hypothesis that pili from S. equi serve to anchor bacteria to horse respiratory tract epithelial cells, enabling colonization and tissue invasion.  This project is supported by the Morris Animal Foundation.

Role of bacteriophages and microbiota in the control of bacterial infections in aquaculture.  The skin of fish and its mucus layer play an important role in maintaining homeostasis.  This tissue is populated with communities of bacteria and bacteriophages, identified as the microbiota.  Some of the bacterial species that form the microbiota are likely to modulate the fish susceptibility to bacterial infections, whereas the bacteriophage population has the power of influencing the dynamics of the bacterial communities within the microbiota.  Our lab is interested in (1) defining the effects of specific environmental changes on the composition of the skin mucus microbiota, and the impact of these changes on the fish susceptibility to bacterial infections; and in (2) identifying bacterial species and bacteriophages that have an impact on the growth/survival of bacterial pathogens causing diseases in fish.  We hope that results from this study will lead to the development of sustainable approaches for preventing and controlling outbreaks of bacterial infections in aquaculture.


Graduate Fields

Dr. Marquis is a member of the following Graduate Fields:


Lab Members

Michael Maguire, Postdoctoral Associate
Kelly Sams MPS, Research technician

Lab Alumni


Related Links


Selected References

O’Neil, H.S., B.M. Forster, K.L. Roberts, A.J. Chambers, A.P. Bitar, and H. Marquis. 2009. The propeptide of the metalloprotease of Listeria monocytogenes controls compartmentalization of the zymogen during intracellular infection. J. Bacteriol. 191:3594-3603.

Zemansky, J., B.C. Kline, J.J. Woodward, J.H. Leber, H. Marquis, and D.A. Portnoy. 2009. Development of a mariner-based transposon and identification of Listeria monocytogenes determinants, including the peptidyl-prolyl isomerase PrsA2, that contribute to its hemolytic activity. J. Bacteriol. 191:3950-3964.

Xayarath, B., H. Marquis, G. C. Port, and N. E. Freitag. 2009. Listeria monocytogenes CtaP is a multifunctional cysteine transport-associated protein required for bacterial pathogenesis. Mol Microbiol. 74:956-973.

Slepkov, E.R., A. Pavinski Bitar, and H. Marquis. 2010. Differentiation of propeptide residues regulating the compartmentalization, maturation and activity of the broad-range phospholipase C of Listeria monocytogenes. Biochem. J. 432:557-563.

Forster, B.M., A. Pavinski Bitar, E.R. Slepkov, K.J. Kota, H. Sondermann, and H. Marquis. 2011. The metalloprotease of Listeria monocytogenes is regulated by pH. J. Bacteriol. 193:5090-5097.

Forster, B.M., J. Zemansky, D.A. Portnoy, and H. Marquis. 2011. The post-translocation chaperone PrsA2 regulates the maturation and secretion of Listeria monocytogenes proprotein virulence factors. J. Bacteriol. 193:5961-5970.

Foster, B.M. and H. Marquis. 2012. Protein transport across the cell wall of monoderm Gram-positive bacteria. Mol. Microbiol. 84:405-413.

Forster, B.M., A. Pavinski Bitar, and H. Marquis. 2014. A non-catalytic histidine residue influences the function of the metalloprotease of Listeria monocytogenes. Microbiol. 160:142-148.

Blank, B.S., D.S. Abi Abdallah, J.J. Park, E.V. Nazarova, A. Pavinski Bitar, K.J. Maurer, and H. Marquis. 2014. Misregulation of the broad-range phospholipase C activity increases the susceptibility of Listeria monocytogenes to intracellular killing by neutrophils. Microb. Infect. 16:104-113.

Abi Abdallah, D.S., A. Pavinski Bitar, F. Oliveira, S. Kamhawi, C. Meneses, J.J. Park, S. Mendez, J. Valenzuela, and H. Marquis.  2014. A Listeria monocytogenes-based vaccine that secretes sand fly salivary protein LJM11 confers long-term protection against vector-transmitted Leishmania major. Infect. Immun. 82:2736-2745.