Plants- Drug Interactions Against Some Multi-drug Resistant Microorganisms Causing Urogenital Tract Infections in Cameroon

Abstract

Background: Multi drug resistance is an increasing phenomenon plaguing the use of antibiotics nowadays. This favors the spread of pathogenic microorganisms causing a major public health problem. Antimicrobial compounds from medicinal plants can be used synergistically to enhance the activity of standard drugs when used concurrently. The aim of this work was to evaluate the ability of extracts from Skirakiopsis elliptica (SE), Rumex abyssinicus (RA), Nauclea pobeguinii (NP) and Picralima nitida (PN) to potentiate the activity of 7 antibiotics against resistant bacteria from urogenital tract infections.

Methods: Using the micro-dilution and the checkerboard methods, the MIC of various agents and the combination effect of extracts and antibiotics were obtained respectively.

Results: A total of 37 additive interactions with Fractional Inhibitory Concentration index (FICI) comprise between 0.56-0.95 and 35 indifferent interactions FICI comprise between 1.03-1.98. No antagonism (FICI >4) was revealed as well as no synergistic effect (FICI <0.5). However, we could notice a decrease at up to 64 fold in MIC of most antibiotics when combined with these extracts. The concentration of Doxycycline was decreased by Nauclea pobeguinii aqueous extracts (NPE) at up to 64-fold on S. saprophiticus.; that of Norfloxacin and Doxycycline was reduced by aqueous extract of Skirakiopsis elliptica (SEE) on E.coli at up to 32 and 16-fold respectively. Conclusion: The results of this study can be exploited to potentiate the antimicrobial activity of antibiotics involved in this study in the bacterial growth inhibition of resistant germs incriminated here.