Antibacterial Activity of Methanol Extract of Red Dragon Fruit Peel ( Hylocereus polyrhizus) against MethicillinSusceptible Staphylococcus aureus ( MSSA) ATCC 25923 and Methicillin Resistant Staphylococcus aureus (MRSA) In Vitro

Abstract

Background: Staphylococcus aureus is one of the most virulent Staphylococcus which could cause systemic
broad-spectrum infections and developed resistant strains. Red dragon fruit (Hylocereus polyrhizus) peel
has a broad antibacterial activity against both gram-negative and positive bacteria, including Staphylococcus
aureus. Objective: To determine and compare the antibacterial activity of methanol extract of red dragon
fruit peel against Methicillin-Susceptible Staphylococcus aureus ATCC 25923 and Methicillin-Resistant
Staphylococcus aureus. Method: Well diffusion test method was performed on 5 concentrations: 100%,
75%, 50%, 25%, and 0%, dissolved in DMSO 10% where at a concentration of 100% contains 1g/mL
extract. The inhibition zone elicited as clear zone around the well then measured and analyzed with SPSS
using One-Way ANOVA and Post Hoc LSD, to determine the significance of each concentration. Results:
The mean diameter of the inhibition zone observed towards Methicillin-Susceptible Staphylococcus aureus
was 9.5333 ± 0.26822 - 15.4167 ± 0.22048, while bigger zone was found in Mueller-Hinton plate with
Methicillin-Resistant Staphylococcus aureus which is 12.30 ± 0.20817 - 17.80 ± 0.25166 mm. Conclusion:
This study showed that methanol extract of red dragon fruit peel has antibacterial activity against S. aureus,
and shows higher antibacterial activity against Methicillin-Resistant Staphylococcus aureus than MethicillinSusceptible Staphylococcus aureus.