Antibacterial activity of Thymus pallidus Batt. and determination of the chemical composition of its essential oil

This study aims to evaluate extra-and intracellullar antimycobacterial activity of Arbutus unedo L. leaves-extracts. We tested the aqueous and ethanol extracts of Arbutus leaves effect against three mycobacteria growth, and showed that aqueous extract and the part I of ethanol extract have a remarkable extracellular antimycobacterial activity. The MIC (Minimum inhibitory concentration) of the part I of ethanol extract is 5.59 ± 0.69 mg/ml for Mycobacterium aurum A + and 6.02 ± 0.76 mg/ ml for Mycobacterium smegmatis MC 2 and Mycobacterium bovis PPI. The part I of arbutus ethanol-extract, used at 6.02 ± 0.76 mg/ml, has a bactericidal effect on M. smegmatis MC 2 located within the rat peritoneal macrophages.

Despite the declaration of tuberculosis (TB) as a global emergency by the world health organization (WHO) about 20 years ago, the worldwide problem of this disease has worsened due to increased drug resistance of tuberculosis bacilli and acquired immune deficiency syndrome (AIDS) pandemic. Consequently, fight against multidrug and extensively drug-resistant TB is a high priority for public health and research. The present work describes the isolation of a Bacillus pumilus strain secreting a metabolite of protein nature capable of inhibiting mycobacterial growth (Mycobacterium smegmatis, Mycobacterium aurum and Mycobacterium bovis BCG). This metabolite is not toxic, accumulates within the macrophage and inactivates the bacilli with a comparable efficiency to that of the pure commercial antimycobacterial substance Amikacin.