Antibacterial Activity of Cocoa Husk Liquid Smoke (Theobroma cacao L.) Against Methicillin-Resistant Staphylococcus aureus

Infectious diseases caused by methicillin-resistant Staphylococcus aureus bacteria are categorised as a priority AMR by WHO. This condition is exacerbated by the limited development of antibiotics and other treatment options, and needs an alternative antibacterial. Cocoa husk liquid smoke has long been shown to have antibacterial activity against Staphylococcus aureus, but its efficacy against methicillin-resistant Staphylococcus aureus (MRSA) has not yet been tested. This study aims to determine the inhibitory activity of cocoa husk liquid smoke against MRSA bacteria through in vitro testing. In vitro test used a completely randomized design with three replications. The variations in cocoa husk liquid smoke concentrations were 1%, 2.5%, 5%, 10%, 20%, 40%, 70%, and 100%, as well as the positive control was vancomycin, and the negative control was sterile distilled water. The data obtained were analyzed using one-way ANOVA followed by a Tukey post-hoc test at a 5% significance level. The results showed that the diameter of the inhibition zone increased from 2.5% to 100%. However, treatments at 1% to 20% did not differ significantly from sterile distilled water (p > 0.05). The 100% concentration treatment showed a significant difference (p>0.05) from the other cocoa pod husk liquid smoke concentrations and was categorized as strong, although its inhibition zone remained lower than that of the vancomycin positive control. Under the conditions tested, the 100% treatment produced the largest inhibition zone against the tested isolate. These findings need to be further developed to determine the safety of cocoa pod husk liquid smoke as an MRSA antibacterial and to address the issue of post-harvest cocoa waste.