1. Antimicrob Agents Chemother. 2015
Sep;59(9):5747-60. doi: 10.1128/AAC.00827-15. Epub
2015 Jul 13.
Cellular
pharmacokinetics and intracellular activity of the novel peptide deformylase inhibitor GSK1322322 against Staphylococcus aureus
laboratory and clinical strains with various resistance phenotypes: studies
with human THP-1 monocytes and J774 murine macrophages.
Peyrusson F(1), Butler D(2), Tulkens
PM(1), Van Bambeke F(1).
Author information:
(1)Pharmacologie cellulaire et moléculaire, Louvain
Drug Research Institute, Université catholique de
Louvain, Brussels, Belgium. (2)GlaxoSmithKline, Collegeville, Pennsylvania, USA. francoise.vanbambeke@uclouvain.be.
GSK1322322 is a
peptide deformylase inhibitor active against
Staphylococcus aureus strains resistant to currently marketed antibiotics. Our
aim was to assess the activity of GSK1322322 against intracellular S. aureus
using an in vitro pharmacodynamic model and, in
parallel, to examine its cellular pharmacokinetics and intracellular disposition. For
intracellular activity analysis, we used an established model of human THP-1
monocytes and tested one fully susceptible S. aureus strain (ATCC 25923) and 8
clinical strains with resistance to oxacillin, vancomycin, daptomycin,
macrolides, clindamycin, linezolid, or moxifloxacin. Uptake, accumulation,
release, and subcellular distribution (cell fractionation) of [(14)C]GSK1322322 were examined in uninfected murine J774
macrophages and uninfected and infected THP-1 monocytes. GSK1322322
demonstrated a uniform activity against the intracellular forms of all S.
aureus strains tested, disregarding their resistance phenotypes, with a maximal
relative efficacy (Emax) of a 0.5 to 1 log10 CFU
decrease compared to the original inoculum within 24h and a static
concentration (C s) close to its MIC in broth. Influx and efflux were very fast
(<5 min to equilibrium), and accumulation was about 4-fold, with no or a
minimal effect of the broad-spectrum eukaryotic efflux transporter inhibitors
gemfibrozil and verapamil. GSK1322322 was recovered in the cell-soluble
fraction and was dissociated from the main subcellular organelles and from
bacteria (in infected cells). The results of this study show that GSK1322322,
as a typical novel deformylase inhibitor, may act
against intracellular forms of S. aureus. They also suggest that GSK1322322 has
the ability to freely diffuse into and out of eukaryotic cells as well as
within subcellular compartments.
Copyright © 2015,
American Society for Microbiology. All Rights Reserved.
PMCID: PMC4538490
[Available on 2016-03-01]
PMID: 26169402 [PubMed - in
process]