title: Antimicrobial activities of clove and thyme extracts.
abstract: OBJECTIVE
  It has been postulated that geographical locations of the herbs affect the constituents of their essential oils and thus the degree of their antimicrobial action. This study examine two samples of clove obtained from Sri Lanka and Zanzibar and two samples of thyme from Iran and Oman to determine the antimicrobial potential of their extracted oils.
  
  
  METHODS
  The active agents in each plant were extracted by steam distillation and by boiling. The antimicrobial activities of the extracts were determined at neat and by two-fold dilutions in well agar diffusion technique using Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Streptococcus pyogenes, Corynebacterium species, Salmonella species, Bacteroides fragilis and Candida albicans.
  
  
  RESULTS
  All oil extracts possessed antimicrobial activity against all bacteria and yeast tested. Their water extracts exhibited lower antimicrobial activity, though thyme aqueous extract was active only against S. aureus. The lowest concentration of antimicrobial activity (0.1% i.e., 1:1024) was obtained with thyme oil extract using Candida albicans. There was no significant difference in antimicrobial activity between clove obtained from Sri Lanka or Zanzibar or thyme obtained from Iran or Oman.
  
  
  CONCLUSIONS
  Our experiment showed that the country of origin of the herbs has no effect on their antimicrobial activity. However, further work is necessary to ascertain why Candida albicans displayed remarkable degree of sensitivity with the extracts than all the other organisms test.
authors: Department of Microbiology and Immunology, Sultan Qaboos University, College of Medicine and Health Sciences, P.O.Box 35, Al-Khod, Muscat 123, Sultanate of Oman.
authors: B C
authors: BC
authors: Nzeako
authors: Zahra S N
authors: ZS
authors: Al-Kharousi
authors: Zahra
authors: Z
authors: Al-Mahrooqui