A COMPARATIVE STUDY ON THE EFFECT OF PLANT EXTRACTS WITH THE ANTIBIOTICS ON ORGANISMS OF HOSPITAL ORIGIN

Thirty five plants belonging to twenty families were studied for their antimicrobial activity. Among the plants tested, 43 % showed antimicrobial activity. Fifteen plants belonging to 10 families exhibited activity against gram positive bacteria and gram negative bacteria. Four plants namely Azadirachta indica, Garadenia jasminoides, Magnifera indica, and Wrightia tinctora showed an appreciable activity against the gram positive bacteria and seven plants against gram negative organisms. Leaf extract of Tabermontana coronaria showed a maximum zone of inhibition (24 mm) against Staphylococcus aureus and the leaf extract of Sida cordifolia showed a maximum zone (20 mm) against Corynebacteriun diphtheriae. Mentha piperanta gave a maximum zone size against E,coli (22 mm) and Vibrio cholerae (20mm). The inhibitory percentage of the leaf extracts against various pathogens were observed to be Staphylococcus aureus (40%), E.coli (28%), Shigella sp (25%), Salmonella sp (22%), Pseudomonas aeruginosa and Bacillus subtilis (20%), Klebsiella pneumoniae and Proteus vulgaris (17%), Vibrio cholera (14%) and Corynebacterium diphtheriae (11%). The results suggested that the leaf extracts of various plants has significant antibacterial activity against the tested microorganisms. The present study is done to compare the activity of the plant extracts with the activity of currently used antibiotics against the selected organisms.