E. Fidelma Boyd, Ph.D.


BISC 682 Molecular Mechanisms of Pathogens
BISC 850 Advanced Topics in Microbiology

Research Interests

Vibrio parahaemolyticus a halophile with diverse traits and disease pathology
Vibrio parahaemolyticus is a halophile and salt is an absolute requirement for growth. Vibrio parahaemolyticus is the leading cause of bacterial seafood borne gastroenteritis worldwide and is an important pathogen of fish and shellfish.

In our group, we study the following

1.     The role of quorum sensing regulators in the osmotic stress tolerance response  

2.     Bacterial factors required for host colonization

3.     How bacterial metabolism influences bacterial host interactions

Vibrio cholerae, the causative agent of the dreaded diarrheal disease cholera

For cholera infection, two virulence factors are indispensable; cholera toxin and the toxin corregulated pilus, and both are contained on mobile and integrative genetic elements (MIGEs).

Our group identified a pathogenicity island named Vibrio Pathogenicity Isalnd-2, which encodes the genes required for sialic acid scavenging, uptake and catabolism and showed that these genes were important for host colonization.  

In our group, we study the following;

1.      How pathogenicity islands integrate and excise from the bacterial chromosome

            2.      The evolution of pathogenicity islands among bacteria

            3.      The role of island cargo genes in the physiology of the bacterium

Vibrio vulnificus a marine bacterium and opportunistic pathogen of humans

Vibrio vulnificus is one of the most deadly bacterial pathogens known with a mortality rate of nearly 70% in susceptible individuals. In this species, we study the synthesis of the amino sugar nonulosonic acid, a sialic acid-like molecule. 

In our group, we study the following

1.      Sialylation of the bacterial cell wall

2.      How sialylation influences cell physiology

3.      Bacterial metabolism impact on host competitiveness

Research Group

Gwendolyn Gregory, B.S., -Ph.D/M.B.A. Graduate student program, (B.S.), Osmotic tolerance regulation

Kent Kwah, B.S., -M.S. Graduate student program, (B.S. Montana State University), Diversity and evolution of CRISPR-Cas systems in Vibrio species

Jessica Tague, B.S. -Ph.D Graduate student program, (B.S. Salisbury University), Vibrio parahaemolyticus quorum sensing regulators LuxO, OpaR and AphA functions.

Nathan McDonald, B.S., Ph.D./M.B.A. Graduate student in Chemistry Biology Interface Program, (B.S. University of Delaware).  Sialic acid and sialic acid-like molecules in Vibrio species

Abish Regmi, B.S.Ph.D./M.B.A. Graduate student (B.S. Towson State University). Vibrio parahaemolyticus carbohydrate utilization and metabolic fitness

Daniel Morreale, Undergraduate Researcher, University of Delaware

John Vaile, III, Undergraduate Researcher, University of Delaware

Selected Publications

Regmi, A., Kalburge, S.S., Whitaker, W.B., and E.F. Boyd. 2017. Genomic and phenotypic comparisons among Vibrio parahaemolyticus  isolates uncover diverse carbohydrate utilization patterns . In Preparation.

Richards, G.P., M. A. Watson, D. S. Needleman, J. Uknalis, E. F. Boyd, and J. P. Fay. 2017. Mechanisms for Pseudoalteromonas piscicida-induced killing of Vibrios and other bacterial pathogens. Applied and Environmental Microbiology, AEM.00175-17.

Carpenter, M.R., Kalburge, S.S., Borowski, M.R. Peters, R.R. Colwell, and E.F. Boyd. 2017. CRISPR-Cas and contact dependent secretion systems on excisable pathogencity islands with conserved recombination modules. J. Bacteriology, JB.00842-16.

Kalburge, S.S., Carpenter, M.R., Rozovsky, S., and E.F. Boyd. 2017. Quorum sensing regulators required for metabolic fitness in Vibrio parahaemolyticus. Infection and Immunity, 23;85(3).

McDonald, N.D., J.B. Lubin, N.Chowdhury, and E.F. Boyd.  2016. Host-derived sailic acids are an important nutrient source required for opitimal bacterial fitness in vivo. MBio. 2016 Apr 12;7(2):e02237-15.

Carpenter, M.R., Rozovsky, S., and E.F. Boyd. 2016. Pathogenicity island cross-talk mediated by recombination directionality factors can facilitate excision and spread of virulence genes in bacteria. J. Bacteriol. 14;198(5):766-76   

Lubin, J.B., W.G. Lewis, N.M Gilbert, S. Almagro-Moreno, E.F. Boyd, and A.L. Lewis. 2015. Host-like carbohydrates promote bloodstream survival of Vibrio vulnificus in vivo. Infection and Immunity. 10.1128/IAI.00345-15.

Boyd, E.F., M.R. Carpenter, N. Chowdhury, A.L. Cohen, B.L. Haines-Menges, J.J. Kingston, S. S. Kalburge, J.B. Lubin, S.Y. Ongagna-Yhombi, and W.B. Whitaker. 2015. Postgenomic analysis of the evolutionary history of Vibrio.  Microbiology Spectrum, 3(5).

Ongagna-Yhombi, S.Y., N.D. McDonald, and E.F. Boyd. 2015. Deciphering the role of multiple betaine choline carnitine transporters in the halophile Vibrio parahaemolyticus. Applied and Environmental Microbiology, 81(1):351-63.

Haines-Menges, B.L., Whitaker, W.B., J.B. Lubin, and E.F. Boyd. 2015. Host Sialic Acids: A delicacy for the pathogen with discerning taste. In Metabolism and Bacterial Virulence. Edited T. Conway and P. Cohen, ASM Press. Microbiology Spectrum, 3(4).

Haines-Menges, B.L., Whitaker, W.B., and E.F. Boyd. 2014. The alternative sigma factor RpoE is essential for Vibrio parahaemolyticus cell envelope stress response and intestinal colonization. Infection and Immunity, 82:3667-77.


Interim Chair

Phone: (302) 831-1088

Fax: (302) 831-2281

Email: fboyd@udel.edu

Office: 328 Wolf Hall

Lab: 353 Wolf Hall

Department of Biological Sciences
Wolf Hall
University of Delaware
Newark, DE 19716


  • B.S. -National University of Ireland (Galway, Ireland)
  • Ph.D. - National University of Ireland (Galway, Ireland)
  • Postdoctoral - The Pennsylvania State University
  • Postdoctoral - Harvard University
  • Postdoctoral - Tufts University School of Medicine