Antibacterial Activity of Rose Geranium (Pelargonium graveolens) Essential Oil Against Clinical Isolates of Staphylococcus aureus and Pseudomonas aeruginosa with Different Antimicrobial Resistance Profiles.

Abstract

This research evaluated the antibacterial activity (ABA) of rose geranium (Pelargonium graveolens (L.) L’Hér.) essential oil (EO) against antibiotic-resistant clinical isolates of Staphylococcus aureus and Pseudomonas aeruginosa and assessed its chemical composition. Hydrodistillation was employed to extract EO, and it was analyzed through gas chromatography-mass spectrometry (GC–MS). The agar disc diffusion technique was employed to assess the ABA of the Pelargonium graveolens EO at 50, 100, and 200 mg/mL against the clinical isolates with varying antimicrobial susceptibility profiles. The results of the GC–MS indicated phenylethyl alcohol (74.13%) as the most significant component, then geraniol (10.16), citronellol (7.67), and eugenol (~2). A concentrationdependent ABA of the EO was observed. Against S. aureus, inhibition zones increased from 20.00 ± 0.87 mm (50 mg/mL) to 30.00 ± 1.06 mm (200 mg/mL), while P. aeruginosa showed 24.00 ± 1.25 mm to 30.00 ± 1.61 mm. Geraniol showed the highest activity against S. aureus (up to 50.00 ± 2.76 mm), whereas P. aeruginosa was less susceptible to isolated components. Pelargonium graveolens EO demonstrated a promising potential for ABA against resistant clinical isolates, especially S. aureus. Its potential as a natural antimicrobial agent can be further developed because it has been shown to be possibly associated with the combined contribution of multiple oil constituents.