Inhibitory effect of five essential oils as antimicrobial agents against two disease-causing bacteria in local chicken

Objectives: In response to the propagation of bacteria resistant to many antibiotics, the discovery of new and more efficient antibacterial agents is Inevitable. The present study was designed to evaluate the antimicrobial activity of five essential oil of medical plants.Materials Methods: The method for extraction of essential oil is called Hydrodistillation by Clevenger apparatus. Pre hepatitis and Cloacal samples were spread onto MacConkey agar plates and incubated overnight at 37°C. One of the single colonies from each plate was picked, spread onto Eosin Methylene Blue agar plates, and incubated overnight at 37°C. For isolation of these Bactria from infected chicken using a panel of biochemical tests were performed. Susceptibility of two bacteria to the essential oil was determined by the disc diffusion assay. The culture media was TSAseeded with these bacteria. Paper discs (5mm in diameter) impregnated with essential oils were placed on the surface of the culture plates and incubated at 37°C for 24 hrs and diameter of zone of inhibition were measured in mm.In this study tetracycline disc diffusion was used as control group.Results Conclusion:Three tested essential oilsin the present study displayed significant antibacterial activity against salmonella sp and Escherichia coli but Trachyspermumammi and Pulicariadysentericadid not show any antibacterial effect. The essential oil disc diffusion ofOriganummajorana showed maximum inhibitory effect against salmonella spthat was 20 mm inhibition zone in diameter. The inhibition zone of Foeniculumvulgaredisc was 16 mm against Escherichia coli and 10 mm on salmonella sp culture. Tetracycline disc diffusion inhibition zone about salmonella sp was 14 mm in diameter and 14 mm about the Escherichia coli.Their antibacterial properties indicate that they can be introduced as replacement antibiotics to treatment and complementary therapy.