Biocontrol of Escherichia coli O157

Abstract

The effect of a bacteriophage cocktail (EcoShield) that is specific against Escherichia coli O157:H7 was evaluated against a nalidixic acid-resistant enterohemorrhagic E. coli O157:H7 RM4407 (EHEC) strain on leafy greens stored under either (1) ambient air or (2) modified atmosphere (MA; 5% O2/35% CO2/60% N2). Pieces (~2 x 2 cm2) of leafy greens (lettuce and spinach) inoculated with 4.5 log CFU/cm2 EHEC were sprayed with EcoShield (6.5 log PFU/cm2). Samples were stored at 4 or 10 degrees C for up to 15 d. On spinach, the level of EHEC declined by 2.38 and 2.49 log CFU/cm2 at 4 and 10 degrees C, respectively, 30 min after phage application (p