RESUMEN

Antibiotic resistance has become a major worldwide priority, and identifying natural antimicrobial compounds may help overcome this problem. In this study, ethanolic extracts of 12 plants commonly used in traditional medicine were tested against two strains of methicillin-resistant Staphylococcus aureus (ATCC 33591 and ATCC 43300) in terms of minimum inhibitory concentrations (MICs). Furthermore, the effect of combining plant extracts with clindamycin antibiotic was also investigated using the checkerboard method. Among the tested plants, Camellia sinensis, Thymus vulgaris, Rosmarinus officinalis and Salvia officinalis exhibited potent inhibitory activity against both strains with MICs ranges (125-500 µg ml-1 ). Synergistic activity was confirmed for the four plants combined with clindamycin with fractional inhibitory concentration index <0·5. However, no antagonistic activity was found for these combinations. Our findings suggest that using an antibiotics-plants combination might be a successful technique to reduce antibiotic consumption, which would overcome the antibiotics resistance or delay its onset.

Asunto(s)

Antiinfecciosos , Staphylococcus aureus Resistente a Meticilina , Plantas Medicinales , Antibacterianos/farmacología , Clindamicina/farmacología , Sinergismo Farmacológico , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/farmacología

RESUMEN

Due to their high efficiency and speed of use, alpha scintillation cell is being increasingly utilized for detection of radon (222Rn) in soil gas. The calibration factor of the 110 A active radon cell has been addressed and thoroughly discussed. The sensitivity and the efficiency have been determined. It is found that the sensitivity and the registration efficiency of this scintillation cell (110 A active cell) are equal to 0.015895 cpm/Bq/m3, 59%. Respectively. A nuclear system was adapted to measure the accumulation of radon gas using the active scintillation cell. The growth curves of radon activity have been investigated. Radon emanation, leakage and back diffusion rates from natural occurring radioactive materials has been determined. Compatibility between practical measurements and results based on the theoretical equation were achieved.