Kristi Frank Ph.D.

Education

2002 B.S., Microbiology, B.S., Medical Technology, The University of Montana, Missoula, MT
2007 Ph.D., Biomedical Sciences-Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN

Biography

Dr. Kristi L. Frank is an Associate Professor in the Department of Microbiology and Immunology at Uniformed Services University of the Health Sciences (USU) in Bethesda, MD. A native of Great Falls, MT, she earned her Bachelor of Science degrees in Microbiology and Medical Technology from The University of Montana in Missoula, MT, in 2002. Dr. Frank attended Mayo Graduate School, Mayo Clinic College of Medicine, in Rochester, MN, where she earned her Ph.D. in Biomedical Sciences-Biochemistry and Molecular Biology in 2007. She carried out her dissertation research on Staphylococcus lugdunesis biofilm formation in the laboratory of Dr. Robin Patel. Dr. Frank completed her postdoctoral research in the Department of Microbiology and Immunology at the University of Minnesota in Minneapolis, MN, where she worked with Drs. Gary Dunny and Patrick Schlievert. She joined the faculty at USU in January 2016.

Dr. Frank's lab studies relationships between bacterial pathogens and their hosts in biofilm-associated infections. Biofilms are organized communities of microbes attached to a surface, or to each other, and are encased in a self-produced extracellular matrix. Biofilm growth provides protection from adverse environmental conditions, enables evasion of the host immune defenses, and confers resistance to remarkably high concentrations of antimicrobial agents. Pathogenic bacteria can form biofilms on surfaces throughout a host and on virtually any implantable medical device. Biofilm infections pose a significant challenge to human health because of their chronic nature and the difficulty associated with treating them.

The Frank Lab's current efforts focus in two major areas: 1. Enterococcus faecalis biofilm formation, stress, and adaptation, and 2. treatment and prevention of biofilm infections.

1. Enterococcus faecalis is a Gram-positive bacterium that is both a human commensal and an opportunistic pathogen. Enterococci are exceptionally robust, recalcitrant to many classes of antimicrobial agents, and highly proficient at acquiring virulence factors via horizontal gene transfer. These characteristics have enabled E. faecalis and other enterococci to emerge as leading causes of healthcare-associated infections. In immunosuppressed patients, E. faecalis can cause a myriad of infections with biofilm etiology, including endocarditis, surgical site infections, and catheter-associated urinary tract infections. The Frank Lab pairs animal models of biofilm formation with genetic, molecular, and biochemical approaches to (1) define sensing pathways and regulatory circuits that are involved in triggering stress and adaptive responses in the host environment and (2) identify biofilm-associated virulence factors in E. faecalis and determine how they affect interactions between the bacterium and its host.

2. We also devise new methods to remove biofilms and prevent their formation in multidrug resistant Gram positive and Gram negative bacteria, including Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter cloacae.

Career Highlights: Positions, Projects, Deployements, Awards and Additional Publications

Smith, W. A., C. A. Hutchison, R. V. Scott, S. E. Hinman, N. H. Osborne, N. J. Hamlin, and K. L. Frank. 2023. Evaluation of the risk of Enterococcus faecalis cross-contamination of gutta-percha cartridges. JADA Foundational Science. 2:100021. doi.org/10.1016/j.jfscie.2023.100021

Schaffer, S. D., C. A. Hutchison, C. N. Rouchon, N. V. Mdluli, A. J. Weinstein, D. McDaniel, and K. L. Frank. 2023. Diverse Enterococcus faecalis strains show heterogeneity in biofilm properties. Research in Microbiology. 174:103986. doi: 10.1016/j.resmic.2022.103986

Rouchon, C. N., A. J. Weinstein, C. A. Hutchison, Z. B. Zubair-Nizami, P. L. Kohler, and K. L. Frank. 2022. Disruption of the tagF orthologue in the epa locus variable region of Enterococcus faecalis causes cell surface changes and suppresses an eep-dependent lysozyme resistance phenotype. Journal of Bacteriology. 18:e0024722. doi: 10.1128/jb.00247-22

Rouchon, C. N., J. Harris, Z. Zubair-Nizami, A. J. Weinstein, M. Roky, and K. L. Frank. 2022. The cationic antimicrobial peptide activity of lysozyme reduces viable Enterococcus faecalis cells in biofilms. Antimicrobial Agents and Chemotherapy. 17:e0233921. doi: 10.1128/aac.02339-21

Barnes, A. M. T.*, K. L. Frank*, J. L. Dale, D. A. Manias, J. L. Powers, and G. M. Dunny. 2021. Enterococcus faecalis colonizes and forms persistent biofilm microcolonies on undamaged endothelial surfaces in a rabbit endovascular infection model. FEMS Microbes. 2:xtab014. doi: 10.1093/femsmc/xtab014 *Authors contributed equally.

Barnes, A. M. T., K. L. Frank, and G. M. Dunny. 2021. Enterococcal endocarditis: Hiding in plain sight. Frontiers in Infection and Cellular Microbiology. 11:722482. doi: 10.3389/fcimb.2021.722482

Fleming, D., W. Redman. G. S. Welch., N. V. Mdluli, C. N. Rouchon, K. L. Frank, and K. P. Rumbaugh. 2020. Utilizing glycoside hydrolases to improve the quantitation and visualization of biofilm bacteria. Biofilm. 2:100037. doi: 10.1016/j.bioflm.2020.100037

Colomer-Winter, C. A. O. Gaca, O. N. Chuang-Smith, J. A. Lemos, and K. L. Frank. 2018. Basal levels of (p)ppGpp differentially affect the pathogenesis of infective endocarditis in Enterococcus faecalis. Microbiology (Reading). 164:1254-1265. doi: 10.1099/mic.0.000703

Representative Bibliography