ABSTRACT
Bacterial resistance to antibiotics and synthetic compounds a increasing continously. The aim of this study was to evaluate the antibacterial effects of Pinuseldarica's gum and its alcoholic extract on Staphylococcus aureus and Escherichia coli which cause some skin infections. After preparing pinus eldarica gum, it was diluted in oleic acid to achieve the concentration of 50% and 75%. The concentration of 50% and 75% of gum's extract ah prepared by soaking the gum in alcoholic solution. Oleic acid and cotrimoxazole were used as control groups. Kirby - bauer method was used as an antibiogram test. Data were analysed by ANOVA variance and Tukey HSD test.In comparison of the effect of 50% and 75% of gum on E-coli, we observed that; there we no remarkable differences between them, but these concentrations of gum were more effective than cotrimoxazole on the inhibition of growth of E-coli. In case of Staphylococcus aureus we observec the negative effect of mentioned concentrations of gum, gum's extract and cotrimoxazole on its growth, but there was no considerable differences between the different concentration of gums, 50% of gum with 50% and 75% of gum's extracts and 75% of gum with 50% of gum's extract o Staphylococci growth.Overall, the study showed that Pinuseldarica's gum has strong inhibitory effect a some microbes. This effect can compete with cotrimoxazole on S. aureus and can be effective on cotrimoxazole resistant E-coli