ANTIBACTERIAL MECHANISM OF ACTION OF TAXUS CUSPIDATA STEM ESSENTIAL OIL AGAINST SELECTED FOODBORNE PATHOGENS

This study examined the antibacterial mechanism of action of Taxus cuspidata stem essential oil (TCEO) against foodborne pathogenic bacteria. The TCEO (2,000g/disc) showed potential antibacterial effect as diameters of inhibition zones (32.00.47-44.0 +/- 0.59mm) against the tested foodborne pathogens including Bacillus cereusATCC13061, Listeria monocytogenesATCC7644, Staphylococcus aureusATCC12600, Salmonella typhimuriumATCC43174 and Escherichia coliATCC43889. The minimum inhibitory concentration and minimum bactericidal concentration values of TCEO against the tested bacteria were found in the range of 125-500g/mL and 250-1,000g/mL, respectively. Also, the TCEO had potential inhibitory effect on the cell viability of B.cereusATCC 13061 and E.coliATCC 43889. Moreover, the TCEO revealed its mode of action on membrane integrity as confirmed by marked release of extracellular adenosine 5-triphosphate, 260-nm absorbing materials and efflux of potassium ions (K+) against the tested pathogens. Further, scanning electron microscopic analysis also supported the inhibitory effect of TCEO as confirmed by significant morphological alterations on the cell membrane of the tested pathogens, suggesting its potential efficacy as a natural antibacterial agent. Practical ApplicationCurrently, because of frequent foodborne outbreaks and the rising concern of consumers on the use of chemical preservatives in foods, the food industry is emphasizing the use of natural antibacterial agents of plant origin as safe food preservatives. Some selected plant materials are used as natural antimicrobials in food systems to prevent the growth of foodborne pathogens, resulting in the extension of the shelf-life of processed foods. This study confirmed that Taxus cuspidata stem essential oil showed its antibacterial mode of action against foodborne pathogens through membrane permeabilization and can be used to control the growth of several foodborne pathogens. Hence, it is anticipated that T.cuspidata stem essential oil may have greater potential for its practical applications as an affective and natural food preservative against food deterioration caused by foodborne pathogens.