Using lytic bacteriophages as a biocontrol intervention to eliminate Salmonella in romaine lettuce, mung bean sprouts, mung bean seeds and mung bean germinated sprouts and to prevent shiga-toxigenic Escherichia coli biofilm formation on romaine lettuce

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Zhang, Xuan
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Bacteriophage as a novel biocontrol intervention has been successfully applied in foods to control Salmonella and STEC. This study is to assess the effect of two virulent lytic bacteriophage preparation reducing Salmonella on produce and mung bean seeds, and preventing E. coli O157:H7 biofilm formation on lettuce. Produce and seeds were washed and inoculated with bacteria before treated by bacteriophage. Salmonella population on produce, seeds, and germinated sprouts was determined by total plate count. Lettuce coupons were pretreated with STEC bacteriophage before E. coli O157:H7 biofilm grew on the surfaces. A 2-4 logs Salmonella reduction achieved on produce after treated by phage. SalmoFresh™ combined with STEC phage did not improve phage efficacy compared to SalmoFresh™ alone on produce. The effect of phage was negligible when applying to mung bean seeds and germinated sprouts. Pre-treatment with STEC bacteriophage and cofactors reduced E. coli O157:H7 biofilm formation on lettuce by 1.31 logs. But the reduction was negligible without cofactors.
Bacteriophage, Lettuce, Mung bean sprouts, Mung bean seeds, Germinated sprouts, Biocontrol intervention, Salmonella, E. coli O157:H7, SalmoFresh, Biofilm, STEC bacteriophage