assessing the effect of pineapple extract alone and in combination with vancomycin on streptococcus sanguis

background periodontitis is a major problem that affects a large number of patients in the society. various treatment alternatives have been proposed to control this pathologic condition. streptococcus sanguis is one of the countless pathogens involved in periodontitis. objectives the current study aimed to assess the efficacy of pineapple extract per se and in synergy with vancomycin on the growth activity of s. sanguis. materials and methods an experimental study was designed to determine the minimum inhibitory concentration (mic) of pineapple extract per se and in conjunction with vancomycin. the study was carried out in three stages. serial concentrations of the aqueous pineapple extract, vancomycin, and pineapple plus vancomycin were prepared by broth microdilution technique respectively and were exposed to the standard laboratory strain of s. sanguis (10556 atcc). the lowest concentration of the pineapple extract and the mixed pineapple/vancomycin solution which inhibited bacterial growth was recorded as the mic. results the minimum inhibitory concentration of vancomycin was determined 1 µg/ ml. the pineapple extract failed to show any inhibitory effects per se, however, once added to vancomycin, it reduced the mic to 0.5µg/ml. conclusion prescription of pineapple extract along with antibiotics increases the antibacterial effects of the drug, therefore reduces the minimum inhibitory concentration of the antibiotic.