In Vitro Antimicrobial Activity Of Avicennia Marina (Mangrove)Stem Bark

Abstract

Background: There has been a rising global antimicrobial resistance (AMR) pandemic in the recent past with far-reaching health and socio-economic implications.For example, there has been an emergence of Methicillin resistant Staphylococcus aureus (MRSA), Vancomycin resistant Staphylococcus aureus(VRSA) andextended spectrum beta lactamase-(ESBL) producing strains of Klebsiella spp., E. coli, and Pseudomonas spp. which have caused longer hospital stays and higher cost of care. Search for new approaches inthe treatment of infectious diseases is therefore imperative. Africa has a wide unexploited diversity of plants with bioactive molecules that can be used as antibiotics. For instance, local information shows that mangrove trees, were decades ago being used in the treatment of various ailments along the Kenyan coast. In the recent past,mangrove species such as Rhizohphora sp, Avicennia sp, and Sonneratia sp havebeen shown to have anti-Pseudomonas spp. activities based on which more studies on its activities against other important microbial pathogens such asStaph aureus, Vibrio cholerae, Salmonellatyphi, E. coli and Candida albicans need to be carried out. Objective: To determine thein vitro activity of Avicennia marina extracts against Staphylococcus aureus, Vibrio cholerae,Salmonella typhi, E. coli and Candida albicans Methodology: Barks of Avicennia marinawere collected from Gazi bay in Kwale county. They were washed, air dried, milled and weighed. The material was then used to prepare extracts using different organic solvents(methane, ethyl acetate, dichloromethane, and chloroform) throughmaceration. The crude extractswere rotary evaporated, whereof the pure extractsweresubjected toin vitroantimicrobial susceptibility tests. The zones of inhibition were measured and the minimum inhibitory concentration and minimum bactericidal concentration for eachextract determined. Results: The results from this study showed that the bark of Avicennia marina has significant antimicrobial and antifungal activity. The MIC and MBC values also revealed that at lower concentrations, the extracts exhibited bacteriostatic properties and at higher concentrations exhibited bactericidal properties.