FACULTY SPOTLIGHT

Photo by Derrick Turner Leonel Mendoza, associate professor of medical technology, works in his lab.

Q: You have recently succeeded in using DNA sequences of the parasite Rhinosporidium to show it is not the fungus most have assumed it was. How did your career become entwined with disease-causing organisms that everyone else gave up on long ago?

A: I would say partly by destiny, I guess. I was working at the veterinary school in Costa Rica, when someone asked me to see some horses with a strange skin disease. I went to see these horses, and since then I have been working with this strange disease, pythiosis. We found a vaccine to cure the disease, and named its etiologic agent - Pythium insidiosum. We also developed a complete series of serological diagnostic tests. This work has a lot of similarities to my involvement with Rhino-sporidium. My mentor, Dr. Libero Ajello, called one day and suggested an idea to determine the enigmatic relationship of this pathogen to other living things, a project we concluded three years later. I think it was destiny and a little luck.

Q: You have had to create a new class designation, the Mesomycetozoea, to house the menagerie of organisms you have explored near the animal/fungal boundary. What do you hope to reveal about this part of the tree of life?

A: When my graduate student, Roger Herr, accepted the challenge to use his master’s project to solve the mysterious relationships of Rhinosporidium seeberi, we could not have predicted the outcome of his project. Thus, when he called me at home one night to announce the discovery, I was very surprised to learn that R. seeberi was not only distant from the fungi, but was closely related to a newly discovered (at that time) group of unique organisms located at the point where fungi and animals diverged. We knew that the group needed a new name and we explored several names until we finally came with Mesomycetozoea, which means ‘between fungi and animals.’

Q: Your work with orphan organisms has lead to a vastly increased understanding of the dangerous water mold Pythium and even to a possible treatment vaccine for use in pythiosis cases. How did your vaccine enter the cycle of new medicines, and where is it now?

A: The immunotherapeutic properties of the Pythium insidiosum vaccine were found by serendipity. I was trying to develop a skin test for pythiosis when we found that many horses with the disease were cured after the application of the skin test. In the following 15 years, we further investigated these antigens and confirmed their therapeutic features. The vaccine has been patented. The commercial rights to produce the vaccine have been licensed to a small Texas company. I think the idea of immunotherapy can easily be extrapolated to other diseases with immunological responses similar to that elicited by Pythium insidiosum.

Q: You seem to enjoy tackling problem organisms that have stumped others for decades. Are there any other uncultured species that attract your attention?

A: Yes, we have been working with orphan organisms studied in medical mycology, including Lacazia loboi, the causative agent of lobomycosis. Our team found that this uncultivated fungus was close to other dimorphic fungal pathogens, a taxonomic puzzle that took 70 years to solve. That is in addition to Pythium insidiosum, the fungal-like microbe mentioned above that turned out to be closely related to algae and plants, but very distant from fungi, where it has been placed for a long time, and R. seeberi, that required 100 years to unveil its taxonomic mysteries. There are many uncultivated microbes that remain. We hope to use molecular tools to explore these and other elusive microbial entities.

Q: How have your experiences as a researcher influenced how you conduct your own laboratory as you mentor the next generation of medical technology research?

A: I love to teach students the basics of being a researcher and an investigator. It is not a matter of how much you know about something, or how fast you can answer questions, but about how you can use your experiences to change the field and in the process create the next generation of thinkers. Of course you need to know something - that, however, in my opinion, is secondary. What we need are students who are eager to discover things that are not obvious. We need more students who are not afraid of failure, students who see common things and then think about unusual things. This is one of the main reasons I enjoy being a mentor.

Copyright 2001 Michigan State University Division of University Relations.