نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Introduction: The rise in antibiotic resistance, especially in pathogens like Pseudomonas aeruginosa (PA), highlights the need for alternatives. Lavandula angustifolia has shown promising antimicrobial activity, offering potential for infection control strategies.Methods: The essential oil extracted from L. angustifolia (Zardband Pharmaceutical Co., Iran) was evaluated for its antibacterial activity using well diffusion agar (WDA) and microdilution-based minimum inhibitory concentration (MIC) assays, with concentrations ranging from 16 to 0.031 mg/mL. Antibacterial activity was assessed against Escherichia coli ATCC 25922 and 11 clinical isolates of PA (Gram-negative bacteria), as well as Bacillus cereus ATCC 11778 and Staphylococcus aureus ATCC 23235 (Gram-positive bacteria). The bacterial strains were tested using both the WDM and MIC. After incubation, bacterial growth was quantified by measuring the optical density (OD) using an ELISA reader.
Results: In Gram-negative bacteria, no inhibition zones were observed in the WDA assay, except for one clinical isolate of PA, which exhibited a 10 mm inhibition zone at 100% essential oil concentration. In contrast, Gram-positive bacteria showed clear inhibitory zones in the WDA assay. The MIC for six clinical isolates of PA was 16 mg/mL, while three isolates exhibited MICs of 32 mg/mL, and one isolate had an MIC of 64 mg/mL. One clinical isolate showed a significantly lower MIC of 2 mg/mL. The MIC for E. coli and the tested Gram-positive strains was uniformly 16 mg/mL.
Conclusion: L. angustifolia essential oil showed limited Gram-negative activity, stronger Gram-positive effects, and concentration-dependent inhibition, especially against pathogenic strains like PA
کلیدواژهها English
