Ngoc Pham and Astha Verma
Fighting malaria
Two Virginia Tech graduate students are working from opposite ends to combat malaria, which is a vector-borne infectious disease transmitted through the bite of an infected female mosquito of the genus Anopheles.
In 2010, an estimated 216 million cases of malaria occurred worldwide and 655,000 people died, according to the Centers for Disease Control and Prevention. Although the majority of the cases occur in the African region, where a child dies every 30 seconds from the disease, about 1,500 malaria cases are diagnosed in the United States each year.
Astha Verma, a fifth-year Ph.D. student in the lab of Paul Carlier, professor of chemistry in the College of Science, is working to develop an insecticide that will combat mosquitoes more efficiently without harming humans.
Currently, the pyrethroid-based insecticides used to coat mosquito nets are having a decreasing effect, as mosquitoes evolve and become resistant to the chemical. Because this is the only class of insecticide approved by the World Health Organization to be used on nets, and the most common used in spraying, “there is an urgent need to explore a new class of insecticides,” Verma said.
To tackle this problem, Verma and her lab mates are studying another class of insecticides known as acetylcholinesterase inhibitors, specifically, organic compounds known as carbamates. While carbamates are currently used as agricultural pesticides and pest sprays, the resistance to carbamates is not as extensive as in the case of pyrethroids, according to Verma. They may prove to be a valuable alternative.
“I am lucky that Dr. Carlier gave me the opportunity to work on this project,” Verma said. “I am loving every bit of the contribution I am making. I come from a country which faces the problem of malaria. Through this research I feel I am giving back not only to my people but also to the rest of the world where the problem of malaria is severe.”
"Astha has poured herself into this project, persistently and creatively overcoming many scientific hurdles,” Carlier said. “She even learned how to raise Anopheles mosquitoes from eggs to fully emerged adults, a skill that is rare among chemists!"
Meanwhile, Ngoc Pham, a master’s student in the lab of Troy Anderson, assistant professor of entomology, studies how mosquitos are biologically able to resist insecticides.
Specifically, Pham researches P-glycoproteins, which transport compounds out of the cell and are also thought to be a cell’s first line of defense when exposed to insecticide. Most insecticides attempt to attack the mosquito’s central nervous system, at the blood-brain barrier interface.
While P-glycoproteins are widely studied in other medically and agriculturally important insects, their interference with insecticides in mosquitoes has not been as thoroughly explored. Pham is attempting to shed light on the field by examining interactions in lab mosquitoes. Ultimately, clarification of these interactions could help prevent mosquito resistance to insecticides.
“I feel exceptionally fortunate to be involved in such an important project,” Pham said. “Knowing that my research can lead to a possible identification of a new resistance mechanism for mosquitoes is beyond anything I could have asked.”
"Ngoc has significantly contributed to our examination of insecticide delivery and control of vector mosquitoes,” Anderson said. “She is an essential member of our research team, and an exceptional student and researcher."
This semester, both Verma and Pham received awards from the Division of Agrochemicals at a recent American Chemical Society meeting in Philadelphia, Pa. Verma was awarded first place for her poster presentation titled "Five-membered ring heterocyclic carbamates and carboxamides: The quest for resistance-breaking, species-selective acetylcholinesterase inhibitors against the malaria mosquito." Pham was awarded third place for her poster presentation titled "Evidence for P-glycoprotein modification of insecticide toxicity in vector mosquitoes." There were a total of 20 students participating in the award competition.
Q&A: Meet Astha
Hometown:
Ropar, Punjab, India
Major:
Chemistry, fifth-year
Fralin Advisor:
Dr. Paul Carlier
Other Degrees:
M.S. Chemistry, Panjab University, Chandigarh
Why do you want to be a scientist?
In the beginning I wasn’t quite sure of what I wanted to be in life. Sometimes I thought I would make a good engineer at other times it would be a doctor. But one thing I was sure of since beginning that I loved studying chemistry. I think it was just a matter of getting hands on experience in the lab during college that I realized that this is what I wanted to do. The thrill of exploring the unexplored with a goal to serve the society is the driving force for me to be in this profession.
What attracted you to your particular field?
Academically, I have always been inclined towards the applied part of my subject particularly synthetic chemistry. The very idea of synthesizing a new compound and adding to the existing ones was fascinating. Lot of hard work, permutations and combinations go into the synthesis of a new compound and to see it work as in my case; as an insecticide for mosquitoes- I feel the whole experience becomes thrilling andrewarding.
Your best Eureka! Moment (when something cool happened in your research):
My Eureka moment!!!!. When serendipitously isoxazole carboxamides got synthesized along with the expected product isoxazole carbamates. Now, these carboxamides have an equal share in my thesis as they have turned out to be equally and sometimes more toxic towards the mosquitoes than the isoxazole carbamates.
What are your ultimate career goals?
My ultimate career goal is to work in a major pharmaceutical industry in the field of Drug Discovery. After completion of my PhD, I plan to pursue postdoctoral research in academia, which will allow me to build new skills like computational modeling and other expertise that are required to excel in this field.
Favorite hobby outside of school?
In my spare time I love to travel and explore nature mostly with friends. I love to watch movies especially thrillers.
What’s so great about the Fralin Life Science Institute?
I have regularly participated in the VBID symposium poster sessions organized by Fralin. I feel Fralin provides a great platform for students to interact and learn from experts in interdisciplinary science through symposiums and seminar series.
Q&A: Meet Ngoc
Hometown:
Roanoke, VA
Major/Year:
Entomology, 2nd year master's student
Fralin Advisor:
Dr. Troy Anderson
Other Degrees/Schools:
B.S. Biological Sciences, 2010
Why do you want to be a scientist? When did you know?
I don’t remember a time that I definitively decided that I wanted to be a scientist. However, the feeling of being ecstatic because your experiment works after spending long hours is why I want to be a scientist. I enjoy being able to work in a field that allows me to explore and learn about a topic that enhances my solving abilities every day.
What attracted you to your particular field of science?
In my junior year of college, I was taking drug chemistry where I met Dr. Jeffrey Bloomquist. Through his guidance and the opportunity to do undergraduate research, I realized that I was interested in the toxicological, biochemical, and molecular aspect for insecticide mechanism of action. After a couple of month, I wanted to pursue a career in insect toxicology and pharmacology.
Your best Eureka! Moment (when something cool happened in your research):
My best Eureka moment was probably the first moment when I first saw a difference in mortality of my mosquitoes and knew that my experiment worked. After long hours of doing my experiment, I wanted to continue doing more experiments to see what would happen next. I felt a sense of purpose.
What are your ultimate career goals?
My ultimate career goal is to work as a researcher focusing on the toxicology and pharmacology of insecticide interactions in industry or with the government.
Favorite hobby outside of school?
My favorite hobby outside of school would be hiking. It is a great stress reliever and an excellent place to collect insects.
What’s so great about the Fralin Life Science Institute?
I would say the best part about Fralin is the people. If you ever get a chance to talk to anyone in Fralin, you will find out that everyone is exceptionally intelligent and doing amazing research.