Background:
Current strategies to overcome the global problem of antimicrobial resistance include research in finding new and innovative antimicrobials from plants. This study was carried out to determine the antibacterial activity of plant extracts of
Olea africana
stem-bark,
Psidium guajava
leaves,
Vernonia amygdalina
leaves,
Lantana camara
leaves and
Mangifera indica
leaves which are used in folklore medicine to treat infections of microbial origin in Longisa region of Bomet District, Kenya.
Methods:
Methanol extracts were derived and screened. Standard cultures of
Escherichia coli
ATCC 25922,
Pseudomonas aeruginosa
ATCC 27853, and
Staphylococcus aureus
ATCC 25923 were used in the study. The antibacterial tests used were the agar well diffusion assays at concentration 1gm/ml. Minimum Inhibition Concentration (MIC) was determined in the plant extract that showed some efficacy against the tested microorganisms. Gentamicin (10µg) was used as a positive control.
Results:
The methanol extracts showed weak antibacterial activity against the study organisms compared to Gentamicin. All extracts exhibited a significant bactericidal activity against
S. aureus while
L. camara and
V. amygdalina lacked efficacy against
P.aeruginosa and
E.coli.
O.africana and
P. guajava presented the lowest MIC against
S.aureus (62.5 mg/ml and 250 mg/ml respectively
P.guajava and
M. indica showed analogous MICs against
P.aeruginosa (250 mg/ml).
P.guajava exhibited a better MIC against
E.coli (500 mg/ml).
Conclusions:
This in-vitro study corroborated the antimicrobial activity of the selected plants used in folklore medicine. The plants could be potential sources of new antimicrobial agent.
