Graduate Student Profiles


Pranav S.J.B. Rana | Research Interest: Interactions between neutrophils and Staphylococcus aureus biofilms

I am originally from Kathmandu, the capital city of Nepal. My interest in microbes started growing in high school as I began to understand their contributions to the world. I moved to the United States to earn a B.Sc. in microbiology at the University of Idaho. As a freshman, I had the opportunity to work with Dr. Patricia Hartzell who studied phase variation, a phenomenon where a bacterial sub-population undergoes a change in gene expression. For the next two and a half years, I was studying the effects of myxovirescin, an antibiotic, produced by Myxococcus xanthus on phase variation.

As I started developing an interest in pathogens, I joined the lab of Dr. Elizabeth Fortunato in my senior year to study the mechanisms responsible for the development of birth defects due to human cytomegalovirus congenital infection. These experiences solidified my interest in conducting research on host-pathogen interactions, which led me to pursue a Ph.D. in microbiology. I joined the lab of Dr. Daniel Wozniak in 2019 to study the interactions of neutrophils and Staphylococcus aureus biofilms. My current project aims at understanding the alterations in neutrophil responses caused by biofilms in chronic wounds leading to persistent infections.

Andrew Schwieters | Research Interest: Detection and response of Salmonella to the presence of quorum sensing by other bacterial species

I am originally from the Twin Cities region of Minnesota. I started my undergraduate degree at the University of Minnesota, Morris studying psychology before becoming interested in Biology. I graduated with a Bachelor of Arts in Biology and a minor in Chemistry. After graduating, I worked in food safety and medical device microbiology through commercial labs before joining OSU.

I joined the lab of Dr. Brian Ahmer in 2018 to study quorum sensing in Salmonella. Quorum sensing is a strategy used by bacteria to sense their own population density by producing and secreting small molecules. Salmonella is unusual in this regard because it senses other bacterial species producing small molecules rather than itself. My research is focused on identifying where Salmonella senses other bacteria and how Salmonella changes its behavior in response to the presence of these small molecules.

The Department of Microbiology at OSU is a welcoming community that encourages the growth and development of its graduate students. There are many different fields of research being explored within our department, which provides excellent opportunities for collaboration and learning.

Marissa Berry | Research Interest: Diversity and evolution of bacterial chemosensory systems

I am from Connecticut and received my B.S. from Saint Michael’s College in Vermont in 2019. I majored in Biochemistry with minors in Math and Religious Studies. While getting my undergraduate degree, I had the opportunity to participate in research on the math behind selfassembling DNA structures. The goal was to optimize the path for the DNA to take in order for other researchers to design DNA sequences to most efficiently build structures. Through this experience I learned how much I enjoyed the research process, and it solidified my desire to get my PhD. I was drawn to Ohio State’s program because of the diversity of research. Upon coming to Ohio State after rotating in a diverse selection of labs, I joined Dr. Jouline’s lab researching signal transduction with computational methods in 2020. My focus is on bacterial chemosensory systems that control bacterial chemotaxis and other cellular functions. My project looks at the diversity and evolution of these systems.

Yiwei Liu | Research Interest: Interactions between microbial communities

Curious about microbial organisms, I always wonder how they can have such a tremendous impact on humans. So, as an undergraduate student in Henan Province, China’s agricultural powerhouse, I embarked on the journey towards a scientific career by investigating the multidrug resistance of microbial populations in chicken fecal samples collected from the local factory farms.

This early experience offered me a taste of microbiology research, which I then have developed an insatiable appetite for. In 2014, I went on to pursue a master’s degree in the Department of Microbiology at Nankai University, China. I joined Dr. Weihui Wu’s lab and worked on Pseudomonas. aeruginosa because I have always been extremely interested in human pathogens. My projects were to investigate the antibiotic resistance and persister formation in P. aeruginosa.

After graduation from Nankai University, with my unchanged passion for human pathogens, I joined Dr. Daniel Wozniak’s lab at Ohio State University in 2018 to pursue my PhD degree. My current project is investigating the function of exopolysaccharide Psl in P. aeruginosa and Staphylococcus. aureus interaction. A better understanding of how these two pathogens coexist and cooperatively infect Cystic Fibrosis (CF) patients will help us better understand the progression of chronic lung disease in CF patients and provide new strategies for therapeutic exploitation of the CF lung microbiome.

Lauren Johnson | Research Interest: Host-pathogen interactions and transplacental infections

I am from Wichita, Kansas and I completed my B.S. in Organismal Biology at The University of Kansas in Lawrence, Kansas. I was interested in science in high school but I never considered it as a career. My undergraduate microbiology class and a later virology lab helped me decide on a future in microbiology. After graduation, I worked in research and development for a small vet biologics company in the Kansas City area for several years. It was there that I was able to get hands on experience with cell culture, creating research vaccines, vaccinating and challenging chickens, as well as the regulatory aspects of animal vaccine licensure. Although I enjoyed the work, I knew I wanted to be able to contribute to science a larger way and I had a couple of great mentors who encouraged me to further my education. In 2016, I graduated with my MS in Biological Sciences from Wichita State University and I joined the Microbiology department here at OSU the same year. As a member of Dr. Stephanie Seveau’s lab, I study how Listeria monocytogenes in maternal blood can cross the placenta and infect the fetus. I am interested in how the placenta limits this type of infection, how L. monocytogenes overcomes these defenses and, when the infection cannot be limited, what is the placental response to this infection.