+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Correlation of daptomycin bactericidal activity and membrane depolarization in Staphylococcus aureus

, : Correlation of daptomycin bactericidal activity and membrane depolarization in Staphylococcus aureus. Antimicrobial Agents and ChemoTherapy 47(8): 2538-2544

The objective of this study was to further elucidate the role of membrane potential in the mechanism of action of daptomycin, a novel lipopeptide antibiotic. Membrane depolarization was measured by both fluorimetric and flow cytometric assays. Adding daptomycin (5 micro g/ml) to Staphylococcus aureus gradually dissipated membrane potential. In both assays, cell viability was reduced by >99% and membrane potential was reduced by >90% within 30 min of adding daptomycin. Cell viability decreased in parallel with changes in membrane potential, demonstrating a temporal correlation between bactericidal activity and membrane depolarization. Decreases in viability and potential also showed a dose-dependent correlation. Depolarization is indicative of ion movement across the cytoplasmic membrane. Fluorescent probes were used to demonstrate Ca(2+)-dependent, daptomycin-triggered potassium release from S. aureus. Potassium release was also correlated with bactericidal activity. This study demonstrates a clear correlation between dissipation of membrane potential and the bactericidal activity of daptomycin. A multistep model for daptomycin's mechanism of action is proposed.


PMID: 12878516

DOI: 10.1128/AAC.47.8.2538-2544.2003

Other references

Higginson, J.; Muir, C.S., 1979: Environmental carcinogenesis: misconceptions and limitations to cancer control. Journal of the National Cancer Institute 63(6): 1291-1298

Stocks, I.C.; Lindsey, D.E., 2008: Acute corrosion of the oral mucosa in a dog due to ingestion of Multicolored Asian Lady Beetles (Harmonia axyridis: Coccinellidae). A six-year old mixed-breed dog presented with severe trauma to the oral mucosa suggestive of chemical burn. Sixteen Harmonia axyridis (Coccinellidae) were removed from the oral cavity, which revealed trauma consistent with chemical burn. The beetl...

Anonymous, 1990: Biologically Engineered Polymers 1989. A conference. 31 July-2 August 1989, Cambridge, United Kingdom. Proceedings. International Journal of Biological Macromolecules 12(2): 65-165

Huang, T-Yi.; Liu, Y-Jui.; Stemmer, A.; Poncelet, B.P., 2007: T2 measurement of the human myocardium using a T2-prepared transient-state TrueFISP sequence. fast and motion-insensitive technique suitable for myocardial BOLD contrast imaging is presented. The method, termed TrueFISP, combines T-2 magnetization preparation with steadystate free precession (SSFP) imaging for T-2 relaxation mapping of th...

Anonymous, 1996: Postmenopausal women: HRT today and into the future. Proceedings of the 6th Novo Nordisk International Symposium. Copenhagen, Denmark, 20-30 September 1995. British Journal of Obstetrics and Gynaecology 103 Suppl 13: 1-108

Sallee V.L., 1975: Permeation coefficients for long chain fatty acids in rat intestine. Federation Proceedings 34(3): 310

Flowers R.M.; Royden L.H.; Bowring S.A., 2005: Isostatic constraints on lithospheric thermal evolution; application to the Proterozoic orogen of the Southwestern United States. Geophysical Monograph 154: 125-138

Vianello, F.; Poznansky, M.C., 2007: Generation of a tissue-engineered thymic organoid. The thymic microenvironment provides essential support for the generation of a functional and diverse population of human T cells. In particular, the three-dimensional (3D) thymic architecture contributes to critical cell-cell interactions. We rep...

Shaw, A.Kumar.; Pal, S.Kumar., 2008: Resonance energy transfer and ligand binding studies on pH-induced folded states of human serum albumin. Human serum albumin (HSA) is a very important transporter protein in the circulatory system. It is a multi-domain binding protein, which binds a wide variety of ligands in its multiple binding sites and aids in transport, distribution and metabol...

Zaczek, R.; Schwarcz, R.; Coyle, J.T., 1978: Long-term sequelae of striatal kainate lesion. Brain Research 152(3): 626-632