Department of Biology, University of Botswana, Gaborone, Botswana.
Int J Environ Health Res. 2010 Feb;20(1):27-41. doi: 10.1080/09603120903254025.
The effects of traditionally used medicinal and cosmetic clays in southern Africa on selected microorganisms were studied using microbiological media. The clay pH, microchemical composition, kind of associated microorganisms and antimicrobial activity of clays against test microorganisms were determined. The clays contained varying numbers of microorganisms which ranged from 0 up to 105 CFU/g. Clay pH ranged from 2.3-8.9. Neither Escherichia coli, nor other faecal coliforms were detected. Clays of pH value of <4 displayed antimicrobial activities. Clays which were active against test microorganisms had Na(2)O, Al(2)O(3), SiO(2), SO(3), CuO or Cl(2)O as major components. Microbial activity of clays was attributed mainly to low pH but cations such as Cu, Al, S or Cl and various anions might have contributed to the microbicidal effects. No antimicrobial activity was established for many of the clays commonly used in the treatment of common ailments of microbial origin.
采用微生物培养基研究了南非传统药用和美容用黏土对选定微生物的影响。测定了黏土的 pH 值、微量化学成分、相关微生物种类和黏土对试验微生物的抗菌活性。黏土中含有数量不等的微生物，范围从 0 到 105 CFU/g。黏土的 pH 值范围为 2.3-8.9。未检测到大肠杆菌或其他粪便大肠菌群。pH 值<4 的黏土显示出抗菌活性。对抗试验微生物有效的黏土含有 Na(2)O、Al(2)O(3)、SiO(2)、SO(3)、CuO 或 Cl(2)O 等主要成分。黏土的微生物活性主要归因于低 pH 值，但 Cu、Al、S 或 Cl 等阳离子和各种阴离子可能对杀菌作用有贡献。在用于治疗微生物源常见疾病的许多常用黏土中，没有确定抗菌活性。
