Kevin Macaluso, MS, PhD, Mary Louise Martin Professor in the Department of Pathobiological Sciences (PBS) at the LSU School of Veterinary Medicine (LSU SVM), has been awarded a Research to STOP Neglected Tropical Disease Transmission (R2STOP) award for his research entitled, “Role of arthropods in transmission of leprosy.” His collaborators on this project are Richard Truman, MS (LSU 1978), PhD (LSU 1985), adjunct professor at the LSU SVM and chief for the Laboratory Research Branch with the National Hansen’s Disease Program (NHDP); Marla Pena, DVM, PhD, NHDP research fellow; and Rahul Sharma, PhD, NHDP research fellow. This award is for $100,000 a year for two years.

Amblyomma americanum image/ CDC
Amblyomma americanum image/ CDC

Dr. Macaluso’s research focuses on the zoonotic transmission of leprosy from wild armadillos to patients with minimal or rare direct contact with these animals, as well as determining the ability of Amblyomma ticks which commonly infest both humans and armadillos in the southern United States to harbor viable M. leprae and transmit the pathogen between vertebrate hosts.

“Our laboratory focuses on the transmission of arthropod – borne bacterial pathogens (via fleas and ticks). We have really advanced the field’s understanding of the specific mechanisms by which emerging and re-emerging bacterial pathogens enter the blood-feeding arthropod vector and then are transmitted to hosts, including humans,” said Dr. Macaluso. “We are one of many laboratories in the Department of Pathobiological Sciences that are teasing apart the arthropod-pathogen-host interactions to identify novel targets for the prevention of pathogen transmission.”

The National Hansen’s Disease Program is housed at the LSU SVM; therefore, researchers will often collaborate with each other when their projects coincide.

Image/skeeze
Image/skeeze

“Because our departments neighbor one another, we often discuss our research activities. One recent discussion concerned the possible role of arthropods in leprosy transmission, which lead to the initiation of this study,” said Dr. Truman.

The R2STOP called for proposals in early 2016 and had 43 submissions. Only six proposals were awarded, including Dr. Macaluso’s. R2STOP’s purpose is to promote and fund research that will close existing knowledge gaps in the relationship between hosts, environment and the pathogens that cause the conditions known as neglected tropical diseases. The R2STOP program is a research initiative jointly sponsored by Effect Hope and The Leprosy Mission.

In 2015, Dr. Macaluso received funding for $1,850,000 for his work investigating an emerging flea-borne rickettsial disease caused 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 grant is Lane Foil, PhD, Pennington Chair for Wildlife Epidemiology and professor of Entomology.

Project Summary

Zoonotic transmission of leprosy from wild armadillos has been well documented. The majority of patients presenting with zoonotic strains of Mycobacterium leprae note extensive outdoor activity; but only rarely report any history of direct contact with wild armadillos. Whether M. leprae transits to new hosts through the environment independently or with the aid of other organisms, is a fundamental question in leprosy transmission. Many NTDs are spread through the aid of arthropod vectors. M. leprae has limited extracellular survival capacity. Intermediary organisms that sustain viability of leprosy bacilli outside the host could play important roles in leprosy transmission. We propose to determine the ability of Amblyommaticks, which commonly infest both humans and armadillos in the southern United States, to harbor viable M. leprae and transmit the pathogen between vertebrate hosts. Additionally, the host-dependent transcriptional activity of M. leprae will be assessed, providing insight into the molecular basis of pathogenesis.

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