Efektivitas Antibakteri Ekstrak Batang Serai Dapur (Cymbopogon citratus) terhadap Streptococcus pneumoniae dan Pseudomonas aeruginosa: Pendekatan in Vitro

Abstract

Introduction. The uncontrolled use of antibiotics remains a significant public health challenge in Indonesia, contributing to increased mortality from treatmentresistant infections. Cymbopogon citratus (lemongrass) contains bioactive compounds with notable antibacterial, antioxidant, and anti-inflammatory properties, demonstrating efficacy against a range of pathogenic microorganisms. Objective. This study aims to test the antibacterial effectiveness of lemongrass (Cymbopogon citratus) stem extract against Streptococcus pneumoniae and Pseudomonas aeruginosa using in vitro testing methods. Method. This study utilized a true experimental design with a posttest-only control group design. Antibacterial testing was conducted using the well diffusion method, with six treatment groups: positive control (erythromycin 15 μg and ciprofloxacin 5 μg), negative control (DMSO), and lemongrass stem ethanol extracts at concentrations of 25%, 50%, 75%, and 100%, each with 3 replications. Results and Discussion. The average inhibition zones for Streptococcus pneumoniae following treatment with lemongrass stem extract at concentrations of 25%, 50%, 75%, and 100% were 13.76 mm, 17.65 mm, 18.20 mm, and 18.12 mm, respectively. The average inhibition zones for Pseudomonas aeruginosa were 12.16 mm, 12.18 mm, 13.28 mm, and 11.80 mm, respectively. The antibacterial activity observed is attributed to the active compounds in the extract, including flavonoids, alkaloids, tannins, and triterpenes/steroids. Conclusion. Lemongrass stem extract is effective in inhibiting the growth of both Streptococcus pneumoniae and Pseudomonas aeruginosa.