Investigation of antibacterial effects of some medicinal plants and spices on food pathogens

Abstract

In this study, in vitro antimicrobial effectiveness of the water extracts of 26 plants on E. coli O157:H7, L. monocytogenes, Y. enterocolitica and S. aureus was investigated comparatively with that of lactic, citric, salicylic and sorbic acid. While all of the tested acid solutions inactivated Y. enterocolitica and S. aureus completely, sorbic acid just only reduced the counts of E. coli O157:H7 and L. monocytogenes. The growth of S. aureus inhibited by all the plant extracts. E. coli O157:H7 strains were affected by extracts of dog rose, hibiscus, sumach, thyme, clove, lemon balm, Turkish sweetgum, green tea, lime, jasmine, black tea and daisy. Dog rose, hibiscus, sumach, thyme, clove, lemon balm, Turkish sweetgum, safflower, black tea, jasmine, calamus, licorice root, sage, coriander, fennel, ginger, lavender, nettle and mint also inhibited the growth of L. monocytogenes. All of the plant extracts with the exception of daisy, licorice root and sage showed antibacterial activity against Y. enterocolitica at the varying degrees. The findings indicated that the extracts having antimicrobial effect can be used for preservation of food.