eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2015-04-28 6 2 133 136 10.13005/bpj/395 2652 article Iraj Pakzad 1,2 Reza Azizian 1 Farid Azizi Jalilian 1,2 Morovat Taherikalani 1,2 Nourkhoda Sadeghifard 1, 2 Mojdeh Mahdi Kartalaie3 3 Deparment of Microbiology , Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran. Research Committee, Ilam University of Medical Sciences. Deparment of Epidemiology, Faculty of Medicine, Ilam University of Medical Sciences. Antibacterial resistant microorganisms as agents which cause infection diseases are fourth cause of mortality throughout the world, therefore there is a huge attempt to deal with this issue. New antimicrobial agents design based on high bactericidal potential, high specificity and low cross-reaction. Herbal remedy as an ancient treatment is considerable. Previously, herbal extract were exploited to treat infections such as; Aloa vera, Thymus vulgaris, Allium sativum. This study is aimed to investigate the effect of Pistacia atlantica on bacteria and compare its effect with routine antibiotics. Sample size was determined 30 numbers per each bacteria by STATCALC software (EPI-Info). Hydro-extract prepared from Pistacia atlantica that collected from Zagros mountains. Disck diffusion and well embedding method recruited to investigate antibacterial effect. MIC test done for hydro-extract and antibiotics. Statistic analysis done by Square Chi test, t independent test, t-test and fisher test. MIC of Pistacia atlantica extract were 163µg/ml, 104.16µg/ml and 204.67µg/ml for E.coli, Pseudomonas aeruginosa and Staphylococcus aureus, respectively. These funding shown inhibition effect of this herbal extract but it indicate no affect on H.pylori. Funding indicate inhibit effect of hydro-extract on recruited bacteria except H.pylori thereby, it is suggested that phenol/chloroform-extracion could be have inhibit affect on H.pylori. https://biomedpharmajournal.org/vol6no2/antibacterial-effect-of-hydro-extract-of-pistacia-atlantica-on-bacteria-in-in-vitro/ H.pylori Staphylococcus aureus Pseudomonas aeruginosa E.coli Pistacia atlantica Hydro-extraction