Antimicrobial Activity of Allicin against Colonizing Group B Streptococci Isolated from Pregnant Women in Ardabil, Iran

Group B streptococci (GBS) are the major cause of neonatal and maternal infections. They are susceptible to penicillin, ampicillin and first-generation cephalosporins. However, resistance to other antibiotics such as erythromycin and clindamycin is common among GBS strains. The aim of this study was to evaluate the antimicrobial activity of allicin against colonizing GBS strains in vitro. Garlic extract was prepared and allicin was purified using semi-preparative HPLC procedure. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of allicin were determined for 52 GBS strains using microdilution method in Todd Hewitt broth medium. MIC of allicin was 64-128 µg/mL (MIC90 = 128) and MBC of allicin was 128 to 512µg/mL (MBC90= 256) for GBS strains. The results of this study showed that allicin can inhibit growth of GBS in vitro. Further studies on allicin might be worthy of evaluation as a therapeutic agent in treatment of GBS infections.