Antimicrobial activity of coconut water, oil and palm kernel oils extracted from coconut and palm kernel on some plasmid-mediated multi-drug resistant organisms associated with food spoilage

Abstract

This study is aimed at evaluating the antibacterial and anticandidal activity of coconut oil, fermented and unfermented coconut water and palm kernel oil (PKO) on Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Corynebacterium sp. and Candida albicans. The coconut water was fermented with Saccharomyces cerevisiae and the pH, sugar and alcohol contents were determined before and after fermentation. The plant materials were screened for antimicrobial phytochemicals. The antimicrobial activity of the coconut water, coconut oil and palm kernel oil and the antibiotic susceptibility of the organisms were done on Muiller Hinton agar using disc diffusion method. The plasmids of the organisms were cured using 10% sodium dodecyl sulphate. The pH and ethanol content of the fermented coconut water were higher than the unfermented while the sugar content decreased after fermentation. There were no phytochemicals detected in the coconut water whereas all the phytochemicals were detected in the PKO while only reducing sugar and steroids were absent in the coconut oil. All the bacteria exhibited multi-drug resistance. After plasmid curing, there were reductions in the resistance indicating that the resistance is plasmid mediated. There was a reduction in the percentage antibiotic resistance of Corynebacterium sp. which was 60 and 0% before and after curing respectively. The PKO was more effective in inhibiting the bacteria and Candida sp. than coconut oil but were all resistant to the coconut water. PKO and coconut oil may thus be used as natural substitutes to control E. coli, S. aureus, P. aeruginosa and Candida sp. Key words: Bacteria, antimicrobial, resistance, coconut water, coconut oil, palm kernel oil, phytochemicals.