Introduction: The most important pathogens in nosocomial infections are Staphylococcus aureus and Staphylococcus epidermidis that are associated with catheters and medical implants. Secretion of toxins and exogenous enzymes by S. aureus causes bacteremia and skin abscesses. S. epidermidis is involved in infections of prosthetic joints, intracardiac devices and artificial heart valves. Eremostachys genus is a member of Lamiaceae family and has 5 endemic species in Iran. The aim of this study was to investigate the possible antibacterial properties of Eremostachys extracts against these bacteria. Materials and methods: methanolic extracts of freeze-dried plant leaf and root were prepared by Perculation method. Then Serial dilution of herbal extracts from 0.19 to 100mg/ml in distilled water and 5%DMSO were prepared, the Minimum Inhibition Concentrations (MICs) and Minimum Bactericidal Concentrations (MBCs) were performed according to the CLSI standard protocols in 96-well microplates. The plates were titrated with TTC (Triphenyl tetrazolium chloride)-dye after 24hours of incubation to determine the MIC value. Results: the outcomes revealed that the MICs of leaf extract for S. aureus and S. epidemidis was 25mg/ml and the MICs of root extract were 50mg/ml and 0.7mg/ml for both bacteria. The MBCs of root extract for S. aureus and S. epidemidis were 25mg/ml and 100mg/ml respectively while there was no bactericidal evidence for leaf extract. Discussion: According to the study, Eremostachys root extract, in addition to the therapeutic use of traditional medicine such as cardiovascular disease, anti-inflammatory, antihepatotoxic, antispasmodic, antitumor and anti-viral, hypoglycemic and hypolipidemic, immunomodulator and purgative activities has the ability to inhibit pathogenic bacterial growth that is a good option for the treatment of Staphylococcal disease.

Keywords