Paul Johnson, Ph.D.
Area(s) of Expertise: Microbiology, Antimicrobial Chemotherapy, Molecular Genetics, Microbial Population Genetics (Advising Area of Expertise: Biology, Pre-Medicine)
Area(s) of Expertise: Microbiology, Antimicrobial Chemotherapy, Molecular Genetics, Microbial Population Genetics (Advising Area of Expertise: Biology, Pre-Medicine)
The ability of bacteria to evade killing by antimicrobial agents can be broken down into two broad mechanistic categories: antibiotic resistance and antibiotic tolerance (persistence). Antibiotic resistance can be defined as the ability of an organism to resist the action of, and grow in the presence of, antimicrobial agents due to a heritable genetic mechanism. Contrary to resistance, persistence can be defined as the ability of a sub-population of bacteria to survive exposure to antimicrobial agents while being genetically identical to the sensitive sub-population. Taken together, this means that the persistent bacteria have the same sensitivity to antibiotics that the parental strain did upon subculture, whereas resistant bacteria exhibit stable heritable decreased sensitivity. Dr. Johnson's research interests involve trying to understand how these complementary, yet fundamentally different, mechanisms allow bacteria to escape antimicrobial therapy. His current work uses two model organisms, N. gonorrhoeae and S. aureus.
Oesterle M.E., Conner T.A., Bunch M., Fleming A., Johnson P., Bialonska D: ‘Do Kinesio Tapes Increase the Skin Exposure to Disease Causing Bacteria?’ Am J Infect Control. 2022 Jul 20;S0196-6553(22)00547-8.
Kemp CA, McCullough,DK, Bialonska D, Johnson P. Effect of Bromination on the Quorum Sensing-Inhibiting Properties of Indole-3-Carboxaldehydes in Chromobacterium violaceum AHL System. Microbiol. Res. 2021, 12, 376–382.
Moss J, Clouse A, McCullough D, Wloch-Salamon D, Johnson P, Bialonska D. Aplysinopsins Inhibit Growth of Cryptococcus neoformans by Interfering With Inositol Metabolism. The FASEB Journal. 2019 Apr.
Oesterle ME, Wright K, Fidler M, Johnson P, Bialonska D. Are Ball Pits Located in Physical Therapy Clinical Settings a Source of Pathogenic Microorganisms? American Journal of Infection Control. 2018 Nov 21. pii: S0196-6553(18)30985-4.
Johnson PJ, Shafer WM. The Transcriptional Repressor, MtrR, of the mtrCDE Efflux Pump Operon of Neisseria gonorrhoeae Can Also Serve as an Activator of "off Target" Gene (glnE) Expression. Antibiotics. 2015 Jun;4(2):188-197.
Zalucki YM, Mercante AD, Cloward JM, Ohneck EA, Kandler JL, Goytia M, Johnson PJ, Shafer WM. Function and Regulation of Neisseria gonorrhoeae Efflux Pumps. In: Microbial Efflux Pumps Current Research. Norwich: Horizon Scientific and Caister Academic Press, 2013 Jun.
Ankomah P, Johnson PJT, Levin BR. The Pharmaco – Population and Evolutionary Dynamics of Multi-drug Therapy: Experiments with S. aureus and E. coli and Computer Simulations. PLoS Pathogens. 2013 April; 9(4).
Johnson PJT, Levin BR. Pharmacodynamics, Population Dynamics, and the Evolution of Persistence in Staphylococcus aureus. PLoS Genetics. 2013 January; 9(1) e1003123.
Mercante AD, Jackson L, Johnson PJ, Stringer VA, Dyer DW, Shafer WM. MpeR is a negative regulator of genes (mtrF and mtrR) in the mtr antimicrobial efflux locus in Neisseria gonorrhoeae and modulates antimicrobial resistance through an iron-responsive mechanism. Antimicrobial Agents and Chemotherapy. 2012 Mar;56(3):1491-501.
Ohneck EA, Zalucki YM, Johnson PJ, Dhulipala V, Golparian D, Unemo M, Jerse AE, Shafer WM. A Novel Mechanism of High-Level, Broad-Spectrum Antibiotic Resistance Caused by a Single Base Pair Change in Neisseria gonorrhoeae. MBio. 2011 Sep 20;2(5).
Johnson PJ, Stringer V, Shafer WM. Off-target gene regulation mediated by transcriptional repressors of antimicrobial efflux pump genes in Neisseria gonorrhoeae. Antimicrobial Agents and Chemotherapy. 2011 Jun;55(6):2559-65.
Folster JP*, Johnson PJ*, Jackson L*, Dhulipali V, Dyer DW, Shafer WM. MtrR modulates rpoH expression and levels of antimicrobial resistance in Neisseria gonorrhoeae. Journal of Bacteriology. 2009. Jan;191(1):287-97. *Authors contributed equally to this work.
Shafer WM, Folster JP, Warner DE, Johnson PJ, Rocco J, Balthazar JT, Kamal N, Jerse AE. Expression of the MtrC-MtrD-MtrE Efflux Pump in Neisseria gonorrhoeae and Bacterial Survival in the Presence of Antimicrobials. In: NIAID, NIH: Frontiers in Research. St. Georgiev V, Western KA, McGowan JJ, eds. Totowa: Humana Press, 2008: 55-63.