Inhibitory Activity of Natural Synergetic Antimicrobial Consortia Against Salmonella enterica on Broiler Chicken Carcasses

Abstract

The currently most utilized antimicrobial agent in poultry processing facilities is peracetic acid, a chemical increasingly recognized as hazardous to human health. We evaluated the efficacy of mixtures of natural antimicrobial compounds, namely reuterin, microcin J25, and lactic acid, for reducing the viability of Salmonella enterica and total aerobes on broiler chicken carcasses. The compounds were compared singly and in combination with water and 0.1% peracetic acid. The minimum inhibitory concentrations of reuterin, lactic acid, and microcin J25 against S. enterica serovar Enteritidis were respectively 2 mM, 0.31%, and 0.03 μM. In vitro, the combinations of reuterin + lactic acid and reuterin + microcin J25 were synergic, making these compounds effective at four times lower concentrations than those used alone. Salmonella viable counts fell to zero within 10 min of contact with reuterin + lactic acid at 10 times the concentrations used in combination, compared to 18 h in the case of reuterin + microcin J25. Sprayed onto chilled chicken carcasses, this reuterin + lactic acid mixture reduced Salmonella spp. counts by 2.02 Log CFU/g, whereas reuterin + microcin J25 and peracetic acid reduced them by respectively 0.83 and 1.13 Log CFU/g. The synergy of reuterin with lactic acid or microcin J25 as inhibitors of bacterial growth was significant. Applied as post-chill spray, these mixtures could contribute to food safety by decreasing Salmonella counts on chicken carcasses.

Effects of drinking water supplementation with Lactobacillus reuteri, and a mixture of reuterin and microcin J25 on the growth performance, caecal microbiota and selected metabolites of broiler chickens

“…In our previous study, the minimum inhibitory concentration of RJ on S. enterica was determined to be 0.5 mmol/L (reuterin) and 0.008 μmol/L (microcin J25), respectively [ 16 ]. Concentrations of 1, 5, and 10 times the minimum inhibitory concentration of RJ were used in the present study.…”

“…Combinations may make each antimicrobial compound effective at a lower concentration and the emergence of resistant variants less likely [ 14 , 15 ]. In our previous study [ 16 ], compared to using them alone, the combination of reuterin and microcin J25 (RJ) at lower concentration has already been proved to be synergistic for reducing counts of Salmonella enterica on chicken carcasses.…”

In vitro assessment of skin sensitization, irritability and toxicity of bacteriocins and reuterin for possible topical applications

“…Reuterin was produced by L. reuteri ATCC 53,608 as described previously 14 . An overnight grown culture of L. reuteri in MRS media supplemented with 20 mM glycerol was centrifuged (1500× g , 10 min, 20 °C), and washed with 0.1 M potassium phosphate twice before resuspending them in 300 mM glycerol and incubating anaerobically for 45 min at room temperature.…”

“…Reuterin is a low molecular weight aldehyde produced by bioconversion of glycerol by the lactic acid bacteria ( Lactobacillus reuteri) . The antimicrobial activity of reuterin was extensively studied 14 – 17 . We previously demonstrated that up to 20 mg/mL of reuterin could be safely used as a bio-preservative and therapeutic agent 18 .…”

Resistance Mechanism and Physiological Effects of Microcin Y in Salmonella enterica subsp. enterica Serovar Typhimurium

“…Humans are mainly infected with S. Typhimurium by eating contaminated food of animal origin ( 6 ). Under such conditions, animal food producers and processors must employ efficient preventive strategies to control Salmonella (including the Typhimurium serotype) throughout the supply chain ( 7 ).…”