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.‎