People

Meet the Principal Investigator

David Hendrixson, Ph.D.

David Hendrixson, Ph.D.

Professor

Email
Faculty Profile

University of Arkansas, B.S.

Washington University, Ph.D. (Mentor: Joe St. Geme III, M.D.)

University of Michigan, Post-doctoral Fellow (Mentor: Vic DiRita, Ph.D.)

Dave’s name is on the lab door, but we know everyone else really does all the work (see below). If something is broken or on fire, Dave probably was responsible. And he is the reigning champion for the last 19 consecutive years of the messiest lab bench in the lab. That’s why we like for him to stay in his office where he can keep the 70’s and 80’s music to himself. Outside of the lab, Dave enjoys spending time with his wife and the lab mascot (see below)… and baking new creations and fantasizing about his bakery... and eating cheese… and discovering new awesome socks to wear (at least he thinks they are cool, we know otherwise).

Current Lab Members

Deb Ribardo, Ph.D.

Deb Ribardo, Ph.D.

Senior Research Scientist

Email

Sam Houston State University, B.S.

University of Texas Medical Branch, Ph.D. (Mentor: Ashok Chopra, Ph.D.)

University of Texas Southwestern Medical Center (Mentor: Kevin McIver, Ph.D.)

Deb’s research activities involve identifying novel components of polar flagellar motors and understanding how they contribute to forming a functional rotary motor….plus exploring any other wild ideas that we come up with in the lab. She has earned the nickname ‘MacGyver’ (that is, the OG MacGyver played by Richard Dean Anderson!) for her ability to fix or rig just about anything in the lab. Deb keeps Dave in check and everyone knows that she’s the one who is really in charge.

Sara Peffer, Ph.D.

Sara Peffer, Ph.D.

Post-doctoral Fellow

Email

Texas A&M University, B.S.

University of Texas Health Science Center, Ph.D. (Mentor: Kevin Morano, Ph.D)

After completing her Ph.D. in analyzing the heat shock response in yeast in Houston, Sara made the trek up north to Dallas to join our research program. Sara made quite the change in her research by switching from eukaryotes to prokaryotes by diving into how Campylobacter jejuni recognizes microbiota-generated metabolites in the intestines of avian hosts. When she isn't taking care of the chicken flocks, she is spending time with her ferrets and baking up a storm - her Christmas cookie platters are amazing! 

Angela Freeman

Angela Freeman, Ph.D.

Research Associate

Email

Midwestern State University, B. S.

University of Texas at Arlington, Ph.D. (Mentor: Dr. Cara Boutte)

Angela is performing research that is shedding insight into how cell division of C. jejuni is linked to initiating flagellar biogenesis so that the bacterium maintains its amphitrichous pattern, which is an unusual flagellation pattern in bacteria. She along with Deb help manage the laboratory and keep it running in tip-top shape, which is much appreciated! Angela spends her extracurricular time with her family and dog and doing all the other fun things that come across her path.

Nestor Ruiz

Nestor Ruiz

Graduate Research Assistant 

Email

University of Texas - Austin, B.S.

Nestor has taken over the reins from Kyle (a former student) in understanding how the BumSR two-component system directs a response to intestinal butyrate to promote transcription required for optimal colonization of both the human host (for diarrheal disease) and the avian host (for commensalism). Nestor is always good for a fun, entertaining story about his life - such as his adventures with his roommate or on his family's ranch. He revealed a secret talent by winning Gold in the Javelin Paper Airplane Toss at the 2021 Micro Olympics. Also, he has been rumored to make a mean New York-style cheesecake, but strangely no one in the lab has ever been given a slice to try - so the jury is still out on that!

Alexis Waller

Alexis Waller

Graduate Research Assistant 

Email

University of Maryland - Baltimore County,  B.S.

Alexis is analyzing unusual features of high-torque polar flagellar motors in terms of how they are constructed in comparison to peritrichous flagella. In addition, she is analyzing some uncharacterized proteins that are required for flagellar biosyntheis in C. jejuni. She is spending a lot of time at the microscopes and is becoming a microscopy wizard in the process! She is often on the same trivia team as Nestor or is on a rival team - her trivia superpowers are Pop Culture. She often doesn't think Dave's jokes are funny (but hardly anyone in the lab does either), and she likes to make sure Dave remembers how much older he is than the students.

Amanda Dobbins

Amanda Dobbins

Graduate Research Assistant

Email

University of North Carolina, B. S. 

Amanda is analyzing how the flagellar type III secretion system for the C. jejuni flagellum forms at the poles of bacterial cells. She is analyzing a unique collection of proteins that are important for this process in the bacterium. She has the unfortunate burden of sitting across from Dave and his messy lab bench, but she is a trooper. In her spare time, Amanda enjoys time with her dog and family, listening to classic rock, and traveling and being outdoors.

Fleetwood

Fleetwood

Lab Mascot

Fleetwood is analyzing the caloric requirements for 5 hours of fetching and tug-of-war a day and a long walk, combined with a full day of sleep. He is an expert at finding ANY food anywhere in the immediate vicinity to eat - especially peanut butter. His biggest problems each day are determining which toy will be his favorite and potential target of destruction and making sure everyone around him is paying attention to him.