Biocontrol of the Food-Borne Pathogens Listeria monocytogenes and Salmonella enterica Serovar Poona on Fresh-Cut Apples with Naturally Occurring Bacterial and Yeast Antagonists

Abstract

Fresh-cut apples contaminated with either Listeria monocytogenes or Salmonella enterica serovar Poona, using strains implicated in outbreaks, were treated with one of 17 antagonists originally selected for their ability to inhibit fungal postharvest decay on fruit. While most of the antagonists increased the growth of the food-borne pathogens, four of them, including Gluconobacter asaii (T1-D1), a Candida sp. (T4-E4), Discosphaerina fagi (ST1-C9), and Metschnikowia pulcherrima (T1-E2), proved effective in preventing the growth or survival of food-borne human pathogens on fresh-cut apple tissue. The contaminated apple tissue plugs were stored for up to 7 days at two different temperatures. The four antagonists survived or grew on the apple tissue at 10 or 25°C. These four antagonists reduced the Listeria monocytogenes populations and except for the Candida sp. (T4-E4), also reduced the S. enterica serovar Poona populations. The reduction was higher at 25°C than at 10°C, and the growth of the antagonists, as well as pathogens, increased at the higher temperature.

Effect of a bacteriophage cocktail in combination with modified atmosphere packaging in controlling Listeria monocytogenes on fresh-cut spinach

“…mL nalidixic acid (Nal) (Sigma Aldrich, St. Louis, MO, USA) through a combination of spontaneous mutation and repeated culture methods, in order to distinguish it from the background microflora indigenous to spinach leaves. Similar to the previous reports by other researchers (Leverentz et al, 2003(Leverentz et al, , 2006, L. monocytogenes was found to be resistant to 250 mg/mL Nal. L. monocytogenes grown overnight in TSB supplemented with 250 mg/mL Nal (TSBN250) reached 8 log CFU/mL.…”

“…On average, throughout the course of the study, Lm-Nal R populations on spinach pieces stored under MA and AA were roughly equivalent. The observed reductions in Lm-Nal R populations on fresh-cut spinach treated with ListShield TM are in agreement with results of previous studies (Leverentz et al, 2004(Leverentz et al, , 2006. Supporting the results of this experiment, a recent study concluded that the same MA conditions used in this study in combination with an Escherichia coli O157:H7-specific lytic phage mixture resulted in lower E. coli O157:H7 populations on fresh-cut leafy greens compared to populations on phage-treated, inoculated samples packaged with atmospheric air (Boyacioglu et al, 2013).…”

Development of a nucleic acid lateral flow immunoassay for simultaneous detection of Listeria spp. and Listeria monocytogenes in food

“…Outbreaks caused by L. monocytogenes have been associated with ingestion of a variety of contaminated foods and were reported from many countries, including Australia, Switzerland, France, and the United States [7][8][9][10].…”

Effect of Various Minimal Processing Treatments on Quality Characteristics and Nutritional Value of Spinach

“…In addition to the use of several chemical substances, different bio preservatives are used to prevent the microbial spoilage of minimally processed vegetables. (Haye et al, 2008;Allende et al, 2007;Brown et al, 2011;Leverentz et al, 2006). Minimally processed vegetables are susceptible to microbial growth because they are cut parts of vegetables.…”