Biocontrol of Listeria on cantaloupes with lactic acid bacteria

Abstract

Efficacy of lactic acid bacteria (LAB) Lactobacillus plantarum and Pediococcus pentosaceus for reducing Listeria on cantaloupes was investigated. Cantaloupe surfaces inoculated with Listeria innocua and Listeria monocytogenes in preharvest and postharvest studies, respectively, were treated with or without LAB. Listeria populations were enumerated on days 0, 1, 5, and 7. At the preharvest level, treatment with unwashed LAB (cultures grown in De Man, Rogosa, and Sharpe) significantly reduced L. innocua by 2.1 log and 1.5 log CFU/cm2 on cantaloupes harvested on days 5 and 7, respectively. At the postharvest level, both unwashed LAB and washed LAB (cultures resuspended in phosphate buffer saline) significantly reduced L. monocytogenes by >2.0 log CFU/cm2 on cantaloupes after 7 days of storage at 25°C; the unwashed LAB treatment exerted higher anti‐Listeria efficacy than the washed LAB. Results suggest that these LAB strains offer potential application for reducing Listeria contamination on cantaloupes at preharvest and postharvest levels. Practical applications Listeriosis associated with the consumption of cantaloupes have resulted in 153 illnesses, 148 hospitalizations, and 33 deaths in the United States between 2009 and 2013, which highlight the need for effective interventions to improve cantaloupe safety. Cantaloupes may be contaminated with Listeria at the farm level or during wash step at the packing facility. Lactic acid bacteria (LAB) including Lactobacillus plantarum and Pediococcus pentosaceus can be potentially utilized as biocontrol agents on the surface of the cantaloupes at the farm level or during postharvest wash to reduce the populations of Listeria on cantaloupes. Further, LAB may minimize cross‐contamination of Listeria at the postharvest level.

Antimicrobial Potential of Food Lactic Acid Bacteria: Bioactive Peptide Decrypting from Caseins and Bacteriocin Production

“…Twenty-one LAB isolated from brewer’s grains, all belonging to the genera Lactobacillus and Pediococcus were able to inhibit Listeria monocytogenes growth in vitro [ 51 ]. In agreement with this finding, a recent report describes the efficacy of two LAB species, namely Lactobacillus plantarum and Pediococcus pentosaceus in reducing the amount of Listeria monocytogenes on cantaloupes whose consumption is cause of severe illnesses, hospitalization, and deaths [ 10 ]. A bacteriocinogenic strain of Enterococcus has been reported to be able to reduce Listeria monocytogenes contamination of meat especially at the presence of NaCl and ascorbic acid [ 52 ].…”

“…Regarding spoilage, LAB have been employed to extend the shelf-life of food [ 8 ], when suitably tested to avoid reciprocal antagonistic action with starter strains when fermented food is concerned. Attempts were also made to counteract food-borne infections such as those caused by Staphylococcus aureus [ 9 ] and Listeria monocytogenes [ 10 ]. More recently, LAB have attracted researcher’s attention as alternative treatment to antibiotic therapy [ 11 ].…”

Ability of Two Strains of Lactic Acid Bacteria To Inhibit Listeria monocytogenes by Spot Inoculation and in an Environmental Microbiome Context

“…Antilisterial activities have been attributed to (i) the production of secondary metabolites (e.g., bacteriocins), hydrogen peroxide, and organic acids, (ii) competitive exclusion due to competition for the same resources, or (iii) bacteriophage-mediated lysis ( 36 – 45 ). The potential for the use of biocontrol cultures of lactic acid bacteria (LAB) to reduce pathogen levels has been widely explored for use in food preservation and safety applications ( 38 , 42 , 45 – 49 ). LAB have been also shown to significantly inhibit L. monocytogenes in vitro ( 35 , 38 , 49 – 51 ).…”

The Complex Role of Lactic Acid Bacteria in Food Detoxification

“…Among fresh products, Lis. monocytogenes is found to grow on cabbage, potatoes, asparagus, green beans, broccoli, radishes, corn, cauliflower, lettuce [ 90 ], in refrigerated and cooked eggs [ 92 ], and cantaloupe [ 93 ]. Besides food, strains of Lis.…”