Antibacterial effects of Ziziphora clinopodioides and Mentha spicata essential oils against common food-borne pathogen biofilms on stainless steel sur

The aim of the current study was to assess the effects of Ziziphora clinopodioides independently and in combination with Mentha spicata essential oils against biofilms of six food-borne pathogens in-cluding Listeria monocytogenes, Salmonella Typhimurium, Escherichia coli O157:H7, Bacillus sub-tilis, Bacillus cereus and Staphylococcus aureus developed on the surface of stainless steel coupons. The minimum inhibitory concentrations (MICs) of essential oils (EOs) were determined using broth micro-dilution method. The order of adhered cell counts in biofilms on the stainless steel surfaces was as followed: S. Typhimurium (5.75 log CFU/cm2) > E. coli O157:H7 (5.31 log CFU/cm2) > S. aureus (5.21 log CFU/cm2) > L. monocytogenes (4.62 log CFU/cm2) > B. subtilis (4.23 log CFU/cm2) > B. cereus (4.17 log CFU/cm2). There was significant difference between the population of all investi-gated pathogens on the stainless steel coupons treated with ZEO and MEO (P