Antibacterial Effect of Different Herbal Extracts Against Listeria monocytogenes Strains Isolated from Foods

Abstract

Listeria monocytogenes is a foodborne pathogen frequently isolated from food that causes different public health problems. In recent years, antibiotic resistance of pathogens has become an important problem affecting human health. For this reason, it is crucial to develop an alternative to antibiotics. Thus, the antibacterial effects of herbal extracts and essential oils are frequently investigated. In this article, the antibacterial activity of extracts obtained from 16 different herbs using ethanol, chloroform, acetone, and distilled water was evaluated against L. monocytogenes strains. The extract showing the highest antibacterial effect against L. monocytogenes was St. John‘s Wort extracted in ethanol (31.72 ±0.52 mm). In addition, Myrtus leaf extracted in ethanol (27.2 ±0.52 mm) and St. John‘s Wort extracted in acetone (25.6 ±0.52 mm) showed a high antibacterial effect against L. monocytogenes compared to other extracts. In the study, the solvent ethanol in which St. John‘s Wort and Myrtus leaf were extracted showed the highest antibacterial activity. In contrast, the solvent that rosemary extract showed the highest antibacterial effect was acetone. However, the most antibacterial herb extracted in distilled water was peppermint (7.03 ±0.52 mm). The extracts of marjoram and yarrow did not show any antibacterial effect in any solvent used in the study. In conclusion, more studies are needed to determine the antibacterial effects of herbal extracts against pathogens in foods and their use.