Maria E. Fichera, Ph.D.
B.S., Manhattan College
Ph.D. University of Pennsylvania
At Eastern Since 1998
I have been teaching in the Department of Biology at Eastern University since 1998 and have been department chair since 2008. I was always fascinated by the way in which God intricately designed all living creatures. As an undergraduate biology major, I became interested in research and spent a summer at SUNY Buffalo School of Medicine investigating agents that affect insulin secretion under a fellowship from the Juvenile Diabetes Foundation. At the University of Pennsylvania where I received my Ph.D., I studied the molecular mechanisms of drug action against the intracellular parasite, Toxoplasma gondii.
I love teaching and working with undergraduates and have worked with over 30 students over the years on my Toxoplasma research project. I am also the premed advisor and enjoy assisting students as they apply to medical school and other professional programs (dental, veterinary, physician assistant, and podiatric medicine).
I am blessed with a wonderful family. My husband and I are team leaders for Worldwide Marriage Encounter (www.wwme-philly.org) – a unique weekend experience that revitalizes Christian marriages. We have two loving daughters. Our family attends Mother of Divine Providence Catholic Church in King of Prussia, and we also lead the Respect Life committee.
BIOL 152 (General Biology II), BIOL 310 (Animal Physiology), BIOL 311 (Cell Biology), BIOL 344 (Molecular Biology), BIOL 426, 427 (Senior Thesis Directed Research) and BIOL 495 (Internship).
Why I Teach at Eastern:
I teach at Eastern because it is my second home. Besides the fact that my brother, Dr. Joe Modica, is here, my colleagues and students are like family to me. This dynamic Christian environment is a place I enjoy working in each day. The rigorous science program, coupled with students and professors who work well together and learn from one another, makes Eastern a community that thrives.
My current research explores herbicide action and resistance in Toxoplasma gondii. This parasite, which can infect all vertebrate animal hosts including humans, is a close relative of the parasite that causes malaria. Toxoplasma infection is quite common and goes unnoticed in a large portion of the adult population where a healthy immune system keeps the parasite at bay. However, this parasite can cause disastrous consequences for those with compromised immune systems, such as AIDS patients or the unborn. Infection is controlled through extensive drug treatment protocols, which often yield allergic side effects for the patient. Therefore, alternative treatments to kill Toxoplasma without harming the host are currently being investigated.
In an effort to search for novel chemotherapeutic agents, my research examines herbicide resistance in Toxoplasma gondii. Dinitroaniline herbicides, commercially utilized weed-killers since the 1960’s, have been shown to kill Toxoplasma and other related parasites while exhibiting very low toxicity in mammalian cells. These agents are thought to affect tubulin proteins – cellular building blocks that are necessary to construct microtubules. Microtubules play a role in essential cell activities such as cell division, movement, and intracellular transport. Studies on herbicide action in plants and green algae identified specific mutations in tubulin DNA that correlated with dinitroaniline resistance. To assess the nature of herbicide resistance in Toxoplasma, dinitroaniline-resistant mutants were generated in the laboratory through chemical mutagenesis, and the tubulin genes from mutant parasites were isolated and sequenced.
Parasites resistant to the dinitroaniline herbicide benfluralin exhibited a point mutation in nucleotide position 1801 of α-tubulin (guanine to adenine substitution) which, when translated, revealed a substitution of valine with methionine at amino acid 252. Likewise, parasites resistant to the dinitroaniline herbicide trifluralin exhibited a point mutation in nucleotide position 1850 of α-tubulin resulting in a thymine to cytosine substitution. Translation of this mutated sequence revealed a substitution of methionine with threonine at amino acid 268. These mutations are similar to known mutations that confer resistance to oryzalin (another dinitroaniline) in Toxoplasma or goosegrass.
Electron crystallography data of bovine tubulin dimers was employed to display the mutations on the tubulin protein structure. The amino acid substitutions for the benfluralin and trifluralin mutants are in close proximity of each other in the core of α-tubulin.
To confirm that the identified mutations in the tubulin DNA are responsible for the parasites’ resistance to dinitroaniline herbicides, the mutant tubulin DNA gene will be placed into wild type, non-resistant parasites through transformation, and their conversion into dinitroaniline-resistant parasites will be studied. This aspect of the project is already in progress.
Selected Scholarly Accomplishments:
- Provost Fellowship from Eastern University ($3,000) -May 2007
- Academic Research Enhancement Award from NIH, 1 R15 AI49962-01 “Dinitroaniline herbicide resistance in Toxoplasma gondii” $107,500 (7/15/01-6/30/04)
- The 24th, 21st, 19th and 18th Annual Saint Joseph’s University Sigma Xi Student Research Symposium, St. Joseph’s University, Philadelphia, PA, April 2007-2013. Abstract and poster presentation. Action of dinitroaniline herbicides in the protozoan parasite Toxoplasma gondii (with student presenters).
- “Witnessing God’s creation under the microscope – science as a gift and call to stewardship” – delivered on Jan. 17, 2009 to leaders of First Presbyterian Church of Pottstown on their annual retreat. Invited to speak by Pastor Carter Lester.
- Fichera, M.E. Action of dinitroaniline herbicides in the protozoan parasite Toxoplasma gondii. Annual meeting of the International Society of Protistologists - Providence-Warwick, Rhode Island, 4-9 August 2007. Abstract and oral presentation.
- Mensch, C, Fichera M, and Lawton JA. “Heterologous Expression and Functional Characterization of Secretion and Nuclear Localization Signals in OrfM, a Potential Virulence-Associated Protein from the Plant Pathogen Erwinia amylovora.” 18th Annual Saint Joseph’s University Sigma Xi Student Research Symposium, St. Joseph’s University, Philadelphia, PA, 20 April 2007. Poster presentation.
- Fichera, M.E., Ayana, M., and Heino, A.E. 2005. Action of dinitroaniline herbicides in the protozoan parasite Toxoplasma gondii. Abstract published in Abstract and Index Issue of the Journal of the Pennsylvania Academy of Science, vol. 78, March 2005. Oral presentation.
- Fichera, M.E., Oh, J., Lilley, P., Brown, E. and Roos, D.S. 2003. Dinitroaniline herbicide resistance in Toxoplasma gondii. Abstract published in Abstract Issue: Seventh International Congress on Toxoplasmosis. Oral presentation.
- Fichera, M.E. and D. S. Roos. 1997. The apicoplast: a novel drug target in protozoan parasites. Nature 390: 407-409.
- Tilley, M., M. E. Fichera, M. E. Jerome, D. S. Roos, and M. W. White. 1997. Toxoplasma gondii sporozoites form a transient parasitophorous vacuole that is impermeable and contains only a subset of dense-granule proteins. Infection and Immunity 65: 4598-4605.
- Fichera, M. E., M. K. Bhopale, and D. S. Roos. 1995. In vitro assays elucidate peculiar kinetics of clindamycin action against Toxoplasma gondii. Antimicrob. Agents Chemother. 39(7): 1530-1537.