Physicochemical and Antibacterial Screening of Coconut Oil on some Clinical Bacteria Isolates

Abstract

Coconut (Cocos nucifera) is a palm tree found worldwide mainly used as a staple food crop, source of wood and in traditional medicine. This study investigates physicochemical properties and antibacterial screening of coconut oil on some clinically isolated bacteria; Salmonella typhi, Staphylococcus aureus, Streptococcus pyogenes and Escherichia coli from sputum, faeces and urine. The isolates were characterized based on biochemical tests according to standard methods. Coconut oil was extracted using the wet processing method and physicochemical properties involving Colour, pH, Moisture content, free fatty acid and Peroxide values were also determined accordingly. These properties were found to fall with standard range values of the Association of Official Agricultural Chemists (AOAC). Agar-well diffusion assay was used for sensitivity assessment and zones of inhibition diameter were measured in millimetres. Antibacterial activity of coconut oil was minimal at low volumes, but demonstrated significantly appreciable antimicrobial effect on the test organisms with increase in oil volume. The highest antimicrobial activity of 12.10 mm mean zone of inhibition diameter observed for Staphylococcus aureus, followed by Streptococcus pyogenes having 10.13mm, Escherichia coli 6.96mm, whereas, Salmonella typhi had the lowest inhibition zone of 5.05 mm. Salmonella typhi showed relatively low zone of inhibition even at the higher volume. Coconut oil has demonstrated antibacterial activity on bacterial isolates used for this study and a potential source of antimicrobial agent.