Chemoprophylactic Antimicrobial Activity of Gallium Maltolate against Intracellular Rhodococcus equi

Martens, Ronald J.; Miller, Nicole A.; Cohen, Noah D.; Harrington, Jessica R.; Bernstein, Lawrence R.

doi:10.1016/j.jevs.2007.06.007

« Previous Next »Journal of Equine Veterinary Science
Volume 27, Issue 8 , Pages 341-345, August 2007

Chemoprophylactic Antimicrobial Activity of Gallium Maltolate against Intracellular Rhodococcus equi

Ronald J. Martens, DVM
- From the Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas
- Reprint requests: Ronald J. Martens, Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843-4475.
Nicole A. Miller
- From the Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas
Noah D. Cohen, VMD, MPH, PhD, DACVIM
- From the Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas
Jessica R. Harrington, BS
- From the Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas
Lawrence R. Bernstein, PhD
- Terrametrix, Menlo Park, California

Abstract

The objective of this study was to assess the ability of prophylactically administered gallium maltolate (GaM) to inhibit growth or kill Rhodococcus equi within murine macrophage-like (J774A.1) cells. Cells were treated with three different doses of GaM or a single dose of maltol (equivalent to the concentration present in the highest dose of GaM studied); they were then infected with virulent R. equi and incubated. Quantitative cultures of R. equi from lysed macrophages were obtained at 0, 24, 48, and 72 hours. All GaM dosages resulted in significant reductions of intracellular R. equi compared with untreated control cells, and a dose–response effect was evident. Maltol treatment alone had no significant effect on intracellular R. equi concentrations compared with untreated control cells. Results suggest the potential usefulness of gallium maltolate for the prevention or control of R. equi infections.

Keywords: Rhodococcus equi, Gallium, Chemoprophylaxis, Antimicrobial, Intracellular bacteria