Allium sativum and Group B Streptococcus: antimicrobial and synergistic activity

Abstract Maternal colonization by Streptococcus agalactiae or Group B Streptococcus (GBS) during pregnancy increases the risk of neonatal infection due to vertical transmission from mother to fetus before or during labor. The study aimed to evaluate the antimicrobial activity of the SP80 fraction (obtained from Allium sativum ) and its synergism associated with the antibiotic against strains of GBS. The broth microdilution was used to determine the antimicrobial activity of the SP80 and to establish the MIC of SP80 (2.40 mg/mL). By using, the disk diffusion method, fifty-five clinical isolates and 1 ATCC of GBS were tested against the association of the SP80 fraction with antibiotic PEN and AMP, respectively, for synergistic assessment. The results showed that the association of SP80 + PEN did not alter the response of PEN alone. In contrast, the association of SP80 + AMP caused the mean inhibition halos to increase with a p<0.001 . The SP80 fraction has antimicrobial activity against GBS, and the association with the antibiotic AMP showed a synergistic effect, which did not occur when in association with PEN.