Antibacterial Effect of Lemon Grass (Cymbopogon citratus) Extract Oil (LEO) on the Growth of Bacterial Pathogens Collected from Different Sources

Abstract

Lemon grass (Cymbopogon citratus) is a fast-growing perennial tropical grass belonging to the family and is widely recognized for its broad-spectrum antimicrobial properties. Its essential oil, referred to as Lemongrass Extract Oil (LEO), contains high concentrations of citral (geranial and general), which disrupt bacterial cell membrane integrity and inhibit key metabolic enzymes. This review presents a comprehensive investigation into the antibacterial efficacy of LEO against six clinically significant bacterial pathogens: Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Clostridium perfringens. The antibacterial activity was evaluated using the Disc Diffusion Method and the Minimum Inhibitory Concentration (MIC) assay, following NCCLS and CLSI guidelines. Bacterial isolates were collected from both clinical (urine) sources and standardized microbiological laboratory strains to enable direct comparative analysis. Results revealed significant variation in susceptibility depending on the bacterial species and the origin of the isolate. K. pneumoniae and E. coli clinical isolates showed the largest zones of inhibition (29 ± 0.5 mm and 28 ± 1.5 mm, respectively), while C. perfringens demonstrated complete resistance. B. subtilis showed 100% sensitivity when tested on three different strains. MIC values ranged from 1 µg/ml (highly sensitive strains) to 128 µg/ml (resistant strains). These findings confirm the therapeutic potential of LEO as a natural antimicrobial agent and advocate its further clinical exploration, particularly for the management of urinary tract infections (UTIs), hospital-acquired infections, and antibiotic-resistant pathogens.