Determination of antimicrobial activity
Antimicrobial activity of the aqueous and organic
extracts of the plant sample was evaluated by
the paper disc diffusion method4. For
determination of antibacterial activity, bacterial
cultures were adjusted to 0.5 McFarland turbidity
standard and inoculated onto Nutrient agar
(oxoid) plates (diameter: 15cm). For the
determination of antimycotic activity, all the
fungal isolates and Candida albicans were first
adjusted to the concentration of 106 cfu/ml.
Cultures of Candida albicans were suspended in
sterile solution of 0.9% normal saline and the
spores of the other filamentous fungi were
suspended in Tanquay buffer and all the
cultures were inoculated onto Sabroud Dextrose
Agar plates. Sterile filter paper discs (diameter
6mm for bacteria and 13mm for fungi)
impregnated with 100μl of extract dilutions
reconstituted in minimum amount of solvent at
concentrations of 50 and 100mg/ml were applied
over each of the culture plates previously
seeded with the 0.5 McFarland and 106 cfu/ml
cultures of bacteria and fungi respectively.
Bacterial cultures and those of Candida albicans
were then incubated at 37oC for 18 h while the
other fungal cultures were incubated at room
temperature (30 – 32oC) for 48 h. Paper discs
impregnated with 20μl of a solution of 10mg/ml
of ciprofloxacin and cotrimoxazole (for bacteria)
and nystatin and amphoteracin B (for fungi) as
standard antimicrobials were used for
comparison. Antimicrobial activity was
determined by measurement of zone of
inhibition around each paper disc. For each
extract three replicate trials were conducted
against each organism.