LSU School of Veterinary Medicine professor receives research grant for $1.85 million

Dr. Kevin Macaluso with one of his graduate students, Lisa Brown, in the LSU School of Veterinary Medicine’s Vector-borne Disease Laboratory.

Funding supports research of flea-borne rickettsial diseases


BATON ROUGE, La.—Kevin Macaluso, PhD, Mary Louise Martin Professor in the Department of Pathobiological Sciences, recently received research funding for his work investigating an emerging flea-borne rickettsial diseasecaused by Rickettsia felis, which was originally identified in the U.S. as a human pathogen in 1991 and is now associated with human infection in North and South America, Europe, Africa, Asia and Oceania. The co-investigator on the new grant is Lane Foil, PhD, Pennington Chair for Wildlife Epidemiology and professor of Entomology. This $1,850,000 grant period is 2015-2020.


“Our ultimate goal for this research is to elucidate the biological and molecular mechanisms that are critical to rickettsial transmission by fleas in order to better understand the epidemiology (i.e., incidence, distribution and possible control of diseases and other factors relating to health) of flea-borne rickettsial diseases and identify novel points of intervention,” said Dr. Macaluso. 


The results of the proposed studies will determine if R. felis uses multiple methods for rapid horizontal transmission between fleas independent of a rickettsemic vertebrate host. This is a new paradigm for vector-borne rickettsial diseases. Also, the probability that rickettsial proteins are somehow associated with arthropod transmission has long been a tenant of vector-borne rickettsial diseases; however, this has never been tested in an actual transmission system.


“The focus of this experiment is to define the of horizontal transmission mechanisms through comparative analyses of three distinct rickettsial strains in two different arthropod vectors—cat fleas and rat fleas,” said Dr. Macaluso. “The rickettsial-derived molecules underlying the transmission of R. felis in flea hosts are not known.”


By accomplishing the specific aims outlined in the proposal, these studies will overcome the hurdles by assessing rickettsial transmission by fleas and through identification of Rickettsia-derived molecular constituents essential to transmission events. Thus, this is a multifaceted approach to better understanding the vector and pathogen-associated factors essential to transmission and will provide a platform to examine other flea-borne bacterial pathogens.