Reduction of Escherichia coli O157:H7 in Biofilms Using Bacteriophage BPECO 19

Abstract

Biofilm formation is a growing concern in the food industry. Escherichia coli O157:H7 is one of the most important foodborne pathogens that can persists in food and food-related environments and subsequently produce biofilms. The efficacy of bacteriophage BPECO 19 was evaluated against three E. coli O157:H7 strains in biofilms. Biofilms of the three E. coli O157:H7 strains were grown on abiotic (stainless steel, rubber, and minimum biofilm eradication concentration [MBECTM] device) and biotic (lettuce) surfaces at different temperatures. The effectiveness of bacteriophage BPECO 19 in reducing preformed biofilms on these surfaces was further evaluated by treating the surfaces with a phage suspension (10(8) PFU/mL) for 2 h. The results indicated that the phage treatment significantly reduced (P <0.05) the number of adhered cells in all the surfaces. Following phage treatment, the viability of adhered cells was reduced by 3 log CFU/cm(2), 2.4 log CFU/cm(2), and 3.1 log CFU/peg in biofilms grown on stainless steel, rubber, and the MBECTM device, respectively. Likewise, the phage treatment reduced cell viability by 2 log CFU/cm(2) in biofilms grown on lettuce. Overall, these results suggested that bacteriophages such as BPECO 19 could be effective in reducing the viability of biofilm-adhered cells. Practical Application Our results suggested that bacteriophages such as BPECO 19 could be effective in reducing the viability of biofilm-adhered cells. Therefore, it could serve as a practical method to control the growth of E. coli O157:H7 in biofilms. In fact, bacteriophages could be part of an ideal, eco-friendly biocontrol intervention strategy to control pathogens in biofilms.