Microbiology

Drew Fayram successfully defends MS thesis

Fayram_Allen

Drew Fayram successfully defended his MS thesis, "Characterization of the neutrophil respiratory burst during infection with Francisella novicida," on Thursday, April 25, 2013. Drew is pictured here with his mentor, Dr. Lee-Ann Allen.

Francisella tularensis is a Gram-negative bacterium and the etiological agent of the infectious disease tularemia. This pathogen is extremely infectious and inhalation of as few as 10 organisms can cause potentially fatal pneumonic disease. Due to its extreme virulence and ease of aerosolization, F. tularensis has been weaponized by offensive biological weapons programs since World War II, and consequently has been listed as a tier 1 select agent by the Center for Disease Control and Prevention. Consistent with its ability to cause severe human disease, F. tularensis has developed mechanisms by which it evades detection and killing by the innate immune system. Neutrophils are important contributors to innate host defense, and as such the goal of this thesis was to gain further insight into the interactions between F. tularensis and these cells. Previously, we have shown that this organism employs two mechanisms to inhibit the neutrophil NADPH oxidase, an important enzyme that generates reactive oxygen species used to kill pathogens. In our current study, we demonstrate that the closely related, but avirulent species F. novicida induces activation of the oxidase during phagocytosis by neutrophils. We also show that opsonized F. novicida, but not F. tularensis LVS, engages FcγRIII which can directly induce activation of this enzyme, suggesting that these species interact differently with neutrophils. However, F. novicida is able to inhibit oxidase activity following stimulation of infected neutrophils with diverse heterologous stimuli. Finally, we conclude that two Francisella genes, acpA and katG, do not contribute to NADPH oxidase inhibition by this bacterium. Taken together, these data significantly contribute to our understanding of how Francisella species are able to modulate neutrophil function to evade the killing capabilities of these cells.

ABOUT DREW:

Drew is originally from Anamosa, Iowa. Along with two younger sisters, Keegan and Meredith, Drew was raised by two loving parents, John and Marina, whose encouragement and dedication led to Drew’s participation is a great variety of activities throughout his young life. Following high school graduation in 2005, Drew attended Wartburg College in Waverly, Iowa, where he studied biology and pitched for the varsity baseball team. It was at Wartburg where Drew’s interests in scientific research and microbiology were discovered. He participated in student research in the lab of Dr. Shawn Ellerbroek where he studied the role of RhoG in cell membrane ruffling. It was also during his time at Wartburg that Drew’s attention was caught by an attractive and intelligent biology/nursing student named Lindsay, whom he married in June, 2011.

Upon graduation from Wartburg in 2009 Drew entered the University of Iowa biosciences graduate program. Through his experience in this program, he developed an interest for infectious disease and host-pathogen interactions. Accordingly, he joined the Department of Microbiology and the laboratory of Dr. Lee-Ann Allen where he has spent the last four years studying how the human pathogen Francisella tularensis evades innate immune defense mechanisms. Drew’s time in the Allen lab has been full of new and beneficial experiences, including a trip to Vancouver, BC to present a poster at the 2010 Society for Leukocyte Biology annual meeting, and to St. Louis, MO, to attend the 2011 Midwest Regional Center of Excellence for Biodefense and Emerging Infectious Diseases Research seminar.

Following graduation, Drew plans to pursue a career in public health and is currently awaiting notification of his status for the 2013 CDC/APHL Emerging Infectious Disease Laboratory Training Fellowship. Additionally, Drew’s work with Francisella has fostered an interest in biodefense and biosafety, both of which are aspects of public health he hopes to be involved with in the future.