Antimicrobial activity of the aqueous, methanol and chloroform leaf extracts of Cissus multistriata

摘要

Antimicrobial activity of aqueous, methanol and chloroform leaf extracts of?Cissusmultistriata?were investigated against 8 bacterial and 2 fungal test organisms, using the tube dilution and agar ditch diffusion methods. Aqueous leaf extract had no activity against both the bacterial and fungal test organisms. Both the methanol and chloroform leaf extracts inhibited all the test organisms with chloroform leaf extract showing the highest zone of inhibition against?Escherichia coli?(diameter 25 mm) and least against?Staphylococcus?aureus? (diameter 13 mm). The methanol leaf extract was least inhibitory against?Salmonella typhi?(diameter 8 mm) and most inhibitory against?S.?aureus?(diameter 15 mm). The methanol leaf extract of?C. multistriata?show more antifungal activity compared with chloroform leaf extract, with?Candida?albicans?being more susceptible than?Aspergillus?niger?to both methanol and chloroform leaf extracts. The minimum inhibitory concentration (MIC) of methanol leaf extract show least activity against?Yersinia?enterocolitica?andPseudomonas?aeruginosa?(MIC = 100 mg/ml) and higher activity of MIC at 50 mg/ml against the other bacterial test organisms. The chloroform leaf extract MIC of 100 mg/ml had least activity against?Proteus?mirabilis?and?P.?aeruginosa?and MIC of 20 mg/ml most inhibitory against?E. coli,?Klebsiella?pneumonia?and?S.?typhi. The antimicrobial activity of the heated extracts persisted after exposure to various temperatures between 30oC to 121oC for 15 to 30 min. However, the extract activity decreased as the temperature increased. The killing rate of the MBC of chloroform extract on?E. coli?was 1 cfu/3 min while on?S. ?typhi?was 1 cfu/3.8 min.