The antibacterial activity of thyme water, apple vinegar, grape vinegar, and vB_EcoM-P34 phage against Escherichia coli O157:H7 ATCC 35150 and their potential to be utilized for decontamination on lettuce were examined in this study. Lettuce samples were treated with thyme water, apple or grape vinegar solutions (10, 25, 50%), vB_EcoM-P34 phage (about 108 PFU/mL) or tap water for 30 min after inoculation of lettuce with E. coli O157:H7 at the level of 5.66 log. Depending on the concentration, vinegars and thyme water reduced the bacterial count in lettuce by between 0.78 and 2.69 logs. The most effective reduction was achieved by treatment with vB_EcoM-P34 at 3.23 log. Bacteriophage was the most suitable method for decontamination, followed by grape vinegar, apple vinegar, and thyme water at 50%. However, high concentrations of vinegars and thyme water caused a sharp odor and a slight lightening in the color of the lettuce.

Bacteriophages are considered as alternative antibacterial agents in the food industry and phage therapy due to the widespread of multidrug-resistant pathogen bacteria. The objective of this study was to isolate lytic bacteriophages target to foodborne pathogen Escherichia coli O157:H7. For screening of bacteriophages, 51 samples were collected from sewage, wastewaters of fish farms, slaughterhouses and food factories, and 18 bacteriophages were isolated. The titer of the purified phages samples were changed among 1.7×10 4-1.02×10 8 PFU/ml. All of the isolated phages had lytic activity against E. coli O157:H7 strains and thus formed clear plaques. Four of 18 phages were found to have inhibitory effects against other E. coli strains including CFAI, ATCC 25922 and DSα in addition to E. coli O157:H7. It was observed that only two phages were infective against Salmonella Kentucky DMC35. The Eco-OH-phages were highly infection ability with EOP values from 0.5 to 0.1 against E. coli O157:H7 strains.