Our work was supported financially by a grant from the “Dead Sea Research Center”, a nonprofit organization recognized by the Israel Ministry of Science, which promotes scientific exploration of the Dead Sea area under the auspices of the Ben Gurion University of the Negev Report.
Antimicrobial properties of Dead Sea black mineral mud
Version of Record online: 20 JUL 2005
International Journal of Dermatology
Volume 45, Issue 5, pages 504–511, May 2006
How to Cite
Ma’or, Z., Henis, Y., Alon, Y., Orlov, E., Sørensen, K. B. and Oren, A. (2006), Antimicrobial properties of Dead Sea black mineral mud. International Journal of Dermatology, 45: 504–511. doi: 10.1111/j.1365-4632.2005.02621.x
- Issue online: 20 JUL 2005
- Version of Record online: 20 JUL 2005
Background The unique, black, hypersaline mud mined from the Dead Sea shores is extensively used in mud packs, masks, and topical body and facial treatments in spas surrounding the lake, and in cosmetic preparations marketed worldwide, but little is known about its antimicrobiological properties.
Methods We performed detailed microbial and chemical analysis of Dead Sea mineral mud compounded in dermatological and cosmetic preparations.
Results Using conventional bacteriological media (with or without salt augmentation), we found surprisingly low numbers of colony-forming microorganisms in the mud. The highest counts (up to 20,000 colonies per gram, mostly consisting of endospore-forming bacteria) were obtained on sheep blood agar. Test microorganisms (i.e. Escherichia coli, Staphylococcus aureus, Propionibacterium acnes, Candida albicans) rapidly lost their viability when added to the mud. Zones of growth inhibition were observed around discs of Dead Sea mud placed on agar plates inoculated with Candida or with Propionibacterium, but not with Staphylococcus or Escherichia. The effect was also found when the mud was sterilized by gamma irradiation. Using 35S-labeled sulfate as a tracer, bacterial dissimilatory sulfate reduction could be demonstrated at a low rate (0.13 ± 0.03 nmol/cm3.d).
Conclusion The antibacterial properties of Dead Sea mud are probably owing to chemical and/or physical phenomena. Possible modes of antimicrobial action of the mud in relation to its therapeutic properties are discussed.