Phage Therapy Against Pathogenic Escherichia coli (O104:H4, O157:H7, and O26) Strains in Irrigation Water During Garden Cress (Lepidium sativum Linn.) Vegetation

Fresh produce outbreaks have increased worldwide. Foodborne pathogens are transmitted mostly by contaminated water, and elimination is harder after the transmission. To eliminate pathogens in fresh produce, chemical prevention methods, including chlorine, can be used. However, the usage of chemicals poses a risk to human health, as well as environmental health. Therefore, alternative prevention methods that can be applied in the field should be investigated. This study aims to investigate an alternative method to prevent the pathogenic Escherichia coli strain O26 and Shiga toxin-producing strains O104:H4 and O157:H7 on freshly consumed garden cresses. In this study, garden cresses were treated with bacteriophages after becoming contaminated with pathogenic E. coli strains during growth. After 30 days, the leaves were collected and tested for the presence of E. coli. Its adherence on the leaf surface was investigated with scanning electron microscope (SEM). Although there were significant reductions in both total and biofilm-forming E. coli counts in pathogenic E. coli strain O26 and Shiga toxin-producing strains O104:H4 and O157:H7, which is also confirmed with the SEM images, the counts were not lowered to levels permitted by the EU. Therefore, results showed that phage therapy against pathogenic E. coli strains may be used as a biocontrol agent in combination with additional control measure.