Staphylococci are a major burden on our society causing significant morbidity, mortality, and increased cost in healthcare. Increasing this disease burden is their ability to form biofilms on biomaterials resulfing in increased tolerance to anfibiofics and action of the immune system. Further study on the development and maturation of staphylococcal biofilms may lead to novel therapeufics that lead to their disruption. Staphylococcal biofilms are known to display spatial heterogeneity containing several physiological states including aerobic and anaerobic regions. Maintenance of these physiological states is imperative to the development of a mature biofilm. It is hypothesized that arginine catabolism is crucial for the development and maturation of anaerobic regions within both a Staphylococcus aureus and S. epidermidis biofilm. In fact, several backgrounds of both S. aureus and S. epidermidis contain two complete copies of the arginine deiminase (ADI) operon, one of which is acquired on a pathogenicity island. The ADI operon synthesizes proteins which catabolize arginine resulfing in ATP and ammonia. Within certain microniches of a biofllm environment, the resulting ATP can be used for metabolic purposes whereas the ammonia may be used for pH homeostasis. Studies demonstrate that arginine metabolism is induced during biofilm development and that the acquired (i.e. from pathogenicity island) ADI operon is most transcriptionally active as the biofilm matures. The importance of arginine metabolism will be studied by first exploring the regulatory role of ArcR, a known regulator of ADI expression, during biofilm growth. It is hypothesized that maximal inducfion of the acquired ADI operon occurs during biofilm growth and that Induction under these conditions is ArcR- dependent Secondly, through the use of fluorescent gene fusions, we will examine the temporal and spafial pattern of ADI gene expression within a S. epidermidis and S. aureus biofilm and compare those data to known anaerobic and aerobic regions of a biofilm. Lasfiy, through a mouse foreign body infection model, the relative virulence of ADI mutants in comparison to wild type S. aureus and S. epidermidis w' be determined. Suscepfibility of ADI mutants to anfibiotics will be tested in a guinea pig fissue cage model.

Public Health Relevance

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Program Projects (P01)
Project #
Application #
Study Section
Special Emphasis Panel (ZAI1-TS-M)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Nebraska Medical Center
United States
Zip Code
Yamada, Kelsey J; Kielian, Tammy (2018) Biofilm-Leukocyte Cross-Talk: Impact on Immune Polarization and Immunometabolism. J Innate Immun :1-9
Bhinderwala, Fatema; Lonergan, Samantha; Woods, Jade et al. (2018) Expanding the Coverage of the Metabolome with Nitrogen-Based NMR. Anal Chem 90:4521-4528
Heim, Cortney E; Vidlak, Debbie; Odvody, Jessica et al. (2018) Human prosthetic joint infections are associated with myeloid-derived suppressor cells (MDSCs): Implications for infection persistence. J Orthop Res 36:1605-1613
Svechkarev, Denis; Sadykov, Marat R; Bayles, Kenneth W et al. (2018) Ratiometric Fluorescent Sensor Array as a Versatile Tool for Bacterial Pathogen Identification and Analysis. ACS Sens 3:700-708
Yamada, Kelsey J; Heim, Cortney E; Aldrich, Amy L et al. (2018) Arginase-1 Expression in Myeloid Cells Regulates Staphylococcus aureus Planktonic but Not Biofilm Infection. Infect Immun 86:
King, Alyssa N; Borkar, Samiksha; Samuels, David J et al. (2018) Guanine limitation results in CodY-dependent and -independent alteration of Staphylococcus aureus physiology and gene expression. J Bacteriol :
Mlynek, Kevin D; Sause, William E; Moormeier, Derek E et al. (2018) Nutritional Regulation of the Sae Two-Component System by CodY in Staphylococcus aureus. J Bacteriol 200:
Gries, Casey M; Kielian, Tammy (2017) Staphylococcal Biofilms and Immune Polarization During Prosthetic Joint Infection. J Am Acad Orthop Surg 25 Suppl 1:S20-S24
Krute, Christina N; Rice, Kelly C; Bose, Jeffrey L (2017) VfrB Is a Key Activator of the Staphylococcus aureus SaeRS Two-Component System. J Bacteriol 199:
Moormeier, Derek E; Bayles, Kenneth W (2017) Staphylococcus aureus biofilm: a complex developmental organism. Mol Microbiol 104:365-376

Showing the most recent 10 out of 105 publications