Anti-staphylococcal and antibiotic-potentiating activities of seven Cameroonian edible plants against resistant phenotypes

Abstract

Background: In this study, we evaluated the anti-staphylococcal and antibiotic-potentiating activities against resistant phenotypes of seven Cameroonian dietary plants: Arachis hypogaea; Cola pachycarpa; Curcuma longa; Lycopersicon esculentum; Manihot esculenta; Passiflora edulis and Rubus fellatae. 

Methods: The liquid broth microdilution method was used for the determination of antibacterial activities, while standard methods were used for phytochemical screening to detect the main classes of secondary metabolites in the extracts.

Results: The phytochemical screening revealed that classes of secondary metabolites were selectively detected in extracts. The studied extracts displayed antibacterial activities with minimal inhibitory concentrations (MICs) values ranging from 32 and 2048 µg/mL on the majority of 20 tested staphylococcus strains. Extracts from rhizome of Curcuma longa and leaves of Rubus fellatae presented the broadest spectrum of activity by inhibiting the growth of 95 % and 85 % of tested bacteria strains respectively. The lowest MIC value 32 µg/mL (best activity) was displayed by Curcuma longa. The extracts of Rubus fellatae, Passiflora edulis and Manihot esculenta improved the activity of antibiotics (ceftriaxone, chloramphenicol, tetracycline and erythromycin) towards more than 80 % of tested pathogens.

Conclusion: The present study provides information on the possible use of the tested Cameroonian edible plants in the control of staphylococcal infections including resistant phenotypes. It also indicates that extracts of Rubus fellatae, Passiflora edulis and Manihot esculenta can be used as naturally occurring antibiotic-resistance modulators to tackle MDR (multi-drug resistance) bacteria.