Extracts from the leaves of
Bryophyllum pinnatum
and
Kalanchoe crenata
were screened for their antimicrobial activities. Solvents used included water, methanol, and local solvents such as palmwine, local gin (Seaman's Schnapps 40% alcoholic drink,) and "omi ekan-ogi" (Sour water from 3 days fermented milled maize). Leaves were dried and powdered before being soaked in solvents for 3 days. Another traditional method of extraction by squeezing raw juice from the leaves was also employed. All extracts were lyophilized. These extracts were tested against some Gram-negative organisms (
Escherichia coli
ATCC 25922,
Escherichia coli,
Pseudomonas aeruginosa
,
Klebsiella pneumoniae
,
Shigella flexneri
,
Salmonella paratyphi
, Citrobacter spp); Gram-positive organisms
Staphylococcus aureus
ATCC 25213,
Staphylococcus aureus,
Enterococcus faecalis
,
Bacillus subtilis
) and a fungus (
Candida albicans
). Agar well diffusion and broth dilution methods were used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) at concentrations of 512mg/ml to 4mg/ml. All the organisms except
Candida albicans were susceptible to the extracts obtained from the traditional method. The squeezed-leaf juice of
Kalanchoe crenata was the most active one with MIC of 8 mg/ml against
Pseudomonas aeruginosa,
Klebsiella pneumoniae and
Bacillus subtilis, 32 mg/ml against
Shigella flexneri, 64 mg/ml against
Escherichia coli and 128 mg/ml against the control strain
Staphylococcus aureus while its MBC is 256 mg/ml against these organisms except
Bacillus subtilis and
Klebsiella pneumoniae. The Gram-positive organisms were more sensitive to the methanol and local gin-extract of
Bryophyllum pinnatum. Extracts from other solvents showed moderate to weak activity.