Screening of solvent dependent antibacterial activity of Prunus domestica

Fruit of Prunus domestica was extracted in ethanol. The ethanol extract was further extracted with two solvents ethyl acetate and chloroform. The crude ethanol extract and two fractions (ethyl acetate and chloroform) were screened for their antibacterial activity using the agar well diffusion method.They were tested against nine bacteria; five Gram positive bacteria (Staphylococcus aureus, Streptococcuc intermedius, Bacillus cereus, Bacillus pumilus) and four Gram negative bacteria (Eschrichia coli, Proteus mirabilis Shigella flexneri, Salmonella typhi and Klebsiela pneumoniae). The susceptibility of microorganisms to all three fractions was compared with each other and with standard antibiotic (Ampicillin) Among all fractions ethyl acetate exhibited highest antibacterial activity (average zone of inhibition 34.57mm +/- 1.3)while ethyl alcohol exhibited least antibacterial activity (average zone of inhibition 17.42mm +/- 3.3). Minimum inhibitory concentration of ethanol, ethyl acetate and chloroform fractions was found in the range of 78ug/ml to 2500ugl/ml against gram positive and gram negative bacteria