Antimicrobial activity of combined essential oils of Origanum vulgare L. and Houttuynia cordata T. against Salmonella enteritidis and Salmonella Paratyphi β

Abstract

Based on the determination of the chemical composition of essential oils by GC–MS, the antibacterial activities and mechanism of combined essential oils extracted from Origanum vulgare L. and Houttuynia cordata T. (denoted as C-EO hereafter) were investigated. The possibility of using C-EO as a potential substitute for synthetic antiseptics was studied for the first time. C-EO exhibited significant antibacterial and anti-biofilm activities against Salmonella Enteritidis and Salmonella Paratyphi β. The FICI of C-EO against S. Enteritidis and S. Paratyphi β were all within 0.563, it indicates that C-EO demonstrated additive antibacterial effects. Antibacterial mechanism of C-EO against the two strains was determined by analyzing the completeness of the cell membrane and the counteractant for bacterial biofilm. The finding that C-EO plays a bacteriostatic effect by disrupting cell walls and membranes was verified intuitively via scanning electron microscopy. Results showed that C-EO may potentially play an essential role in food preservation. Novelty impact statement The antibacterial mechanism of the combined EOs (C-EO, which were extracted from Origanum vulgare L. and Houttuynia cordataT) against Salmonella enteritidis and Salmonella paratyphi β was determined for the first time. The C-EO exerted additive antimicrobial effect against S. enteritidis and S. paratyphi β. This C-EO is apparently a potential candidate for future food preservatives.