Treatment of fresh produce with a Salmonella‐targeted bacteriophage cocktail is compatible with chlorine or peracetic acid and more consistently preserves the microbial community on produce

Abstract

Diets rich in minimally processed foods are associated with numerous health benefits, in part, due to their diverse, natural microbiota. However, antimicrobials, such as chlorine and peracetic acid (PAA), that are used to address food safety concerns may damage the natural microflora of fresh produce. One promising approach for targeting pathogenic bacteria in foods without impacting the normal food microbiota are bacteriophages. In this study, we observed that combinational treatment of conventional antimicrobials (PAA and chlorine) and bacteriophages, specifically the Salmonella‐targeted preparation SalmoFresh, retained the bactericidal effectiveness of individual interventions, and in some cases, achieved substantially increased efficacy. Additionally, the bacterial microbiomes of farm fresh and organic produce were less affected after phage treatment compared to PAA and chlorine. Finally, our study revealed that resistance rates against SalmoFresh were relatively minor and unaffected by the stresses introduced after chemical washes and/or bacteriophage treatment.

Characterization of a T4-like Bacteriophage vB_EcoM-Sa45lw as a Potential Biocontrol Agent for Shiga Toxin-Producing Escherichia coli O45 Contaminated on Mung Bean Seeds

“…Ever since FDA granted the first phage product as GRAS in 2006 ( 17 ), phage application used as a microbial intervention alternative became an attractive but underdeveloped technology to be used in the food industry, specifically for produce production. Because of the features of lytic phage application, including host specificity, cost efficiency, and reduction of antimicrobial-resistant bacteria, as novel and alternative antimicrobial interventions ( 24 ), there are several commercial phage products available on the market for the control of foodborne pathogens, such as Listeria monocytogenes , Salmonella spp., and E. coli O157:H7 ( 17 ). Primary efforts toward antimicrobial intervention development focus on E. coli O157:H7, frequently associated with STEC-related infection and foodborne outbreaks, even though the top six non-O157 STEC have also contributed to a similar scale of foodborne outbreaks as well as the severity of illness ( 19 , 25 ).…”

Phage Biocontrol Applications in Food Production and Processing

“…For instance, in the presence of high organic loads, pretreatment of fruits and vegetables with a bacteriophage preparation boosted the efficacy of a produce wash by up to 2 logs (Magnone et al, 2013). Similarly, studies suggest an additive effect also occurs when phages are applied after chemical treatments, as higher reductions were observed in the combined treatments than when the interventions were used alone on apples, cantaloupes, lettuce, and chicken breast (Moye et al, 2020;Sukumaran et al, 2015). Phage biocontrol has also been shown to be effective when combined with modified atmospheric conditions, having better reductions in bacterial counts on chicken breast compared to their storage under aerobic conditions (Sukumaran et al, 2016).…”

“…For example, the traditional decontamination methods are broad-spectrum, killing not only the pathogen of concern but also the natural microflora of the foods, which are often beneficial. In contrast, phage biocontrol, due to the specificity of bacteriophages, enables targeted elimination of the foodborne bacteria in the foods, while maintaining the natural microbial population and preserving the nutritional composition/value of those foods (Moye et al, 2020).…”

Phage Biocontrol Applications in Food Production and Processing

“…For instance, in the presence of high organic loads, pretreatment of fruits and vegetables with a bacteriophage preparation boosted the efficacy of a produce wash by up to 2 logs (Magnone et al, 2013). Similarly, studies suggest an additive effect also occurs when phages are applied after chemical treatments, as higher reductions were observed in the combined treatments than when the interventions were used alone on apples, cantaloupes, lettuce, and chicken breast (Moye et al, 2020;Sukumaran et al, 2015). Phage biocontrol has also been shown to be effective when combined with modified atmospheric conditions, having better reductions in bacterial counts on chicken breast compared to their storage under aerobic conditions (Sukumaran et al, 2016).…”

“…For example, the traditional decontamination methods are broad-spectrum, killing not only the pathogen of concern but also the natural microflora of the foods, which are often beneficial. In contrast, phage biocontrol, due to the specificity of bacteriophages, enables targeted elimination of the foodborne bacteria in the foods, while maintaining the natural microbial population and preserving the nutritional composition/value of those foods (Moye et al, 2020). C. jejuni levels were decreased ∼2 logs on experimentally-contaminated chicken skin after application of phage at an MOI of 100:1 or 1,000:1.…”