About Us


Jessina C. McGregor (PI)

McGregor, Jessina_16 croppedJessina was born and raised in Oregon.  She graduated from Oregon State University with honors bachelors degrees in both Microbiology and International Studies.  Jessina completed her PhD in Epidemiology at the University of Maryland, Baltimore.  In 2006, Jessina returned to Oregon and joined the OSU College of Pharmacy’s Department of Pharmacy Practice.  Her research interests include appropriate and prudent antimicrobial use, multidrug-resistant organisms, and healthcare-associated infections. Jessina also holds an adjunct appointment with the OHSU-PSU School of Public Health.


Caitlin McCracken (Research Analyst)

CMcCracken2Originally a Montanan, Caitlin has lived on both coasts since graduating from Montana State University in 2009.  After a short stay in Los Angeles, Caitlin moved to Boston to complete her Master’s degree in Sociology from Boston College.  During her graduate work she fell in love with the research process, particularly quantitative methods. After completing her Masters in 2014 she worked as an analyst on a study of former professional football players through the Harvard Clinical and Translational Science Center and then later for the department of Sports Medicine at Boston Children’s Hospital.  She joined the OSU/OHSU College of Pharmacy as a Research Analyst in 2018.


Kendall Tucker, PharmD MS (Clinical Pharmacy Fellow)

Kendall is here as a clinical fellow with our group.  Originally from South Carolina, he completed his PharmD at the South Carolina College of Pharmacy, PGY-1 Residency at University of New Mexico Hospitals, and PGY-2 Residency in Infectious Diseases at Novant Health Forsyth Medical Center.  His areas of professional interest include Antimicrobial Stewardship, Gram-negative resistance, and Information Technology. Outside of work, Kendall enjoys reading, sports, photography, and playing board games.


Michael Ray (Epidemiology PhD Student)

Michael grew up in the Tacoma, Washington area and attended Western Washington University where he earned a degree in biochemistry. After graduation, he spent a year in Soweto, South Africa volunteering at an HIV and AIDS NGO. It was this experience that solidified his desire to work in the field of public health. Michael then moved to the Midwest to attend the University of Illinois at Chicago School of Public Health, where he quickly found his calling in the field of epidemiology. After earning his MPH, Michael completed a national health systems integration fellowship with the Illinois Department of Public Health, and then went on to join the Collaborative Research Unit at the Cook County Health and Hospitals System, where he worked for two years. Michael’s research interests include infectious disease transmission, extensively drug-resistant organisms, and social network analysis.  Michael is currently working on his PhD in Epidemiology at the OHSU-PSU School of Public Health. Michael lives in Portland with his wife, Beckah, and their baby boy, Jonah.


Czarinna Posadas (EXITO Undergraduate Research Intern)

Czarinna was born and raised in Saipan, CNMI. After graduating high school, she decided to explore other opportunities and moved to Portland, OR to attend college. In 2019, she graduated with her Associate of Science at Portland Community College. Czarinna is currently working on completing a bachelor’s degree in Public Health at Portland State University as a BUILD EXITO scholar.



Haley Holmer (Epidemiology PhD Student)

Dr. Holmer recently completed her PhD in Epidemiology at the OHSU-PSU School of Public Health. Dr. Holmer is currently completing a Post Doctoral Fellowship with the Center to Improve Veteran Involvement in Care at the VA in Portland Oregon.

Greg Tallman, PharmD MS (Clinical Pharmacy Fellow)

Dr. Tallman completed his clinical pharmacy fellowship in 2018 and is currently an Assistant Professor at Pacific University’s School of Pharmacy.


Sui Kwong Li, MD

Dr. Li completed his infectious diseases fellowship at OHSU and his research with the McGregor research group in 2018. He is now at the University of Pittsburgh Medical Center


Brittany Morgan, MPH

Brittany Morgan HeadshotMs. Morgan completed her MPH and field experience in the McGregor research group in 2018.  She is now a California-EIS Fellow with the California Department of Public Health Tobacco Control Program.