No abstract

This study addresses the problem of pathogenic bacteria resistant to antibiotics isolated from infected chickens and the use of medicinal plants and their bioactive substances in vitro. On 75 strains isolated from a dead chickens belonging to the three families the Enterobactereaceae; the Staphylococeae; the Pseudomonaceae bacteria. The antibiogram tests were used to select ten resistant bacteria strains in this study. Ethonobotanical study was done to select the most medicinal plants used for the therapy of animals in Algeria. The essential oils of six medicinal plants were extracted by Hydro distillation (Clevenger). The plants with their yields in essential oils are: Thymus vulgaris (2.75%), Salvia officinalis (2.50%), Rosmarinus officinalis (2.43%), Thymus capitatus (1.82%), Ruta chalepensis (0.93%), Artemisia herba alba (0.90%). By measuring the activity of the oils on agar medium, this test has provided the following results: The essential oils of different plants gave the diameters of inhibition zones between 0 mm and 53.33 ± 1.53 mm, for the 5 µl discs, and between 0 mm and 52.33 ± 2.52 mm, for the 10 µl discs, while discs of 15 µl, those diameters vary between 0 mm and 56.67 ± 1.15 mm. The results of MICS of oils studied are encouraging, oils of Thymus capitatus, Rosmarinus officinalis and Salvia officinalis share a minimum inhibitory concentration (MIC) between 1.25 and 20 (μL.mL-1) with an effect bactericidal/ bacteriostatic, except the oil Salvia officinalis presents a bactericidal effect. The oils of Thymus vulgaris, Artemisia herba alba and Ruta chalepensis have a MIC respectively of 1.25 to 10 (μL.mL-1), 5 to 40 (μL.mL-1), 1.25 and 40 (μL.mL-1). The effect is bactericidal effect for these oils.