determination of the antimicrobial effects of hydro-alcoholic extract ‎of cannabis sativa on multiple drug resistant bacteria isolated from ‎nosocomial infections

background: the science of identification and employment of medicinal plants dates ‎back to the early days of man on earth. cannabis (hashish) is the most common illegal ‎substance used in the united states and was subjected to extensive research as a ‎powerful local disinfecting agent for mouth cavity and skin and an anti-tubercular agent ‎in 1950.‎ methods: clinical strains were isolated from hospitalized patients in vali-e-asr hospital ‎of arak. the hydro-alcoholic extract of cannabis (5 g) was prepared following liquid-‎liquid method and drying in 45˚c. the antimicrobial properties of the extract were ‎determined through disk diffusion and determination of mic (minimum inhibitory ‎concentration).‎ results: first, the sensitivity of bacteria was detected based on disk diffusion method ‎and the zone of inhibition was obtained for mrsa (12 mm), s.aureus 25923 (14 mm), e. ‎coli esbl+: (10 mm), and klebsiella pneumoniae (7 mm). disk diffusion for ‎pseudomonas and acinetobacter demonstrated no inhibitory zones. through broth ‎dilution method, mic of cannabis extract on the bacteria was determined: e.coli 25922: ‎‎50µg/ml, e.coli esbl+:100 µg/ml, s.aureus 25923:25 µg/ml, mrsa: 50 µg/ml, ‎pseudomona aeroginosaesbl+> 100 µg/ml, pseudomonas: 100 µg/ml, klebsiella ‎pneumoniae: 100 µg/ml, and acinetobacter baumannii> 1000.‎ conclusion: the maximum anti-microbial effect of the hydro-alcoholic extract of ‎cannabis was seen for gram positive cocci, especially s. aureus, whereas non-‎fermentative gram negatives presented resistance to the extract. this extract had ‎intermediate effect on enterobacteriacae family. cannabis components extracted ‎through chemical analysis can perhaps be effective in treatment of nosocomial ‎infections.‎