Abstract: AIM: To study the in vitro interaction of Allicin combined with Cefazolin or Oxacillin against clinical isolates of staphylococcus aureus and staphylococcus epidermidis.METHODS: The protocol was designed by checkerboard method and the MICs of Allicin combined with Cefazolin or Oxacillin against the 40 strains of staphylococci spp.were determined by broth dilution method,the FIC index was calculated according to MIC results.The combined effects were confirmed by FIC index.RESULTS: The percentage of the FIC index less than 0.5,from 0.5 to 1, from 1 to 2, more than 2 was 55%-75%, 20%-40%, 0%-5.88%, 0% respectively.CONCLUSION: The results suggested that synergism and additivity of Allicin combined with Cefazolin or Oxacillinagainst 40 strains of staphylococci were main reaction,and there were little autonomy and no antagonism.

Key words: allicin, Cefazolin, Oxacillin, Gram positive staphylococci, FIC