Anti-Pseudomonal Activity of Leaf Extracts of Myrtaceae Plants against β- Lactamase-Producing Strains

Background: Due to occurrence of extended-spectrum β-lactamases (ESBLs) in Pseudomonas aeruginosa, there is a need for a reliable method to treat clinical isolates of P. aeruginosa that increasingly reported from worldwide. Also the prevalence of multidrug-resistant P. aeruginosa producing betalactamase reported from different parts of the world during the last decades. The Eucalyptus contains a number of compounds with antifungal, antiviral and antibacterial properties and used to control several diseases derived from microbial infections.

Materials and Methods: In this experimental study, Eucalyptus camaldulensis (E. camaldulensis) was used to evaluate the antimicrobial effects against lactamase-producing strains of P. aeruginosa methanol extract of the leaves of this plant, with concentrations of 50, 100, 200 and 400 mg/mL were prepared, and antibacterial activities were evaluated by well diffusion method on strains P. aeruginosa isolated from patients. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was determine by the microplate method.The frequency of the gene encoding bla OXA-10 was studied by polymerase chain reaction (PCR).

Results: In this study, methanol extract of eucalyptus leaves at concentrations of 400 mg/mL was high activity against P. aeruginosa. Minimum inhibitory concentration of the extract on the growth of these bacteria was change to 25 mg/mL. Also MBC of extract showed range from 50 mg/mL respectively.

Conclusion: Result from these finding suggest that, eucalyptus extract, has an inhibitory effect on strains that carrier betalactamase. Also, the effect of extract, risesed by increasing the concentration. The results of this study suggest the traditional use of E. camaldulensis leaves as an antibacterial agent.