Antimicrobial activity of some Teucrium species from Serbia

Abstract

In the Serbian flora, genus Teucrium is represented by six species. In this work, for the first time, antimicrobial properties of methanol, ethyl acetate and acetone extracts of T. scordium L. subsp. scordium, T. scordium L. subsp. scordioides (Schreb.) Arcang. and T. botrys L. were examined [1]. Antimicrobial activity was tested by microdilution method determining minimum inhibitory (MIC) and microbicidal concentration (MMC) against standard and clinical strains of bacteria and fungi: Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans ATCC 10231, Candida albicans and Aspergillus niger [2]. The activity of extracts varied depending on the microorganism species, plant species and type of extract. The extracts of T. scordium subsp. scordium and T. scordium subsp. scordioides showed inhibitory effects towards tested bacteria while T. botrys inhibit only S. aureus ATCC 25923. Antifungal activity was recorded for ethyl acetate extracts of T. scordium subsp. scordium and T. botrys. MIC and MMC values were in range from 0.3mg/ml to >20mg/ml. Among tested extracts, the methanolic showed the greatest inhibitory effects. S. aureus ATCC 25923 was the most sensitive strain. It was inhibited by extracts of tested plants, except ethyl acetate extract of T. botrys. The inhibitory and bactericidal concentrations were lower than 1mg/ml. Susceptibility of S. aureus and P. aeruginosa was moderate with MIC values between 5mg/ml –20mg/ml. E. coli, clinical and standard strain, exhibited susceptibility to the extracts at higher concentration or resistance. Also, tested fungi showed low sensitivity to the extracts.