Evaluation of Antibacterial Activity of <i>Zataria multiflora</i> Against the Expression of <i>icaADB</i> and <i>aap</i> Gene and Biofilm Formation in <i>Staphylococcus epidermidis</i>

Abstract

Background: This study aimed at evaluating the effect of the extract and essential oil of Zataria multiflora on reducing phenotypes and genotypes of biofilm formation in clinical isolates of Staphylococcus epidermidis. Methods: The ability to produce biofilm was evaluated by microtiter plate (MtP) for phenotype and through the presence of icaADB and aap by PCR for genotype among the 153 clinical isolates of Staphylococcus epidermidis. The impact of ethanol extract and essential oil of Zataria multiflora were measured on biofilm formation in phenotypic evaluation based on MtP and on the expression of ica operon and aap by real time-PCR. Results: The results showed that 71.2% of isolates were able to produce biofilms. The PCR results showed that 52.2% and 88.9% of the isolates had icaABD and aap, respectively. In addition, the relative mRNA expression of icaA, icaD, and aap genes were significantly reduced compared to the negative control after treating the Staphylococcus epidermidis RP62A with subMIC concentration of essential oil and extract (P < 0.001). Conclusions: Given the significant inhibitory effect of the extract and essential oil of Zataria multiflora on biofilm formation, it seems that these substances are good options for studies related to controlling biofilm formation in Staphylococcus epidermidis