Efficacy of Antimicrobial Lauric Arginate against <i>Listeria monocytogenes</i> on Stainless Steel Coupons

Abstract

Commercially processed foods become contaminated with Listeria monocytogenes in post-processing environments where favorable conditions help the bacteria thrive. The US Food and Drug Administration has approved Lauric arginate (LAE) as generally recognized as safe (GRAS) for certain food applications. This study evaluated the efficacy of Mirenat-N (LAE dissolved in food-grade propylene glycol) against L. monocytogenes on food contact surfaces. A three-strain cocktail of L. monocytogenes was used to inoculate 24 polished stainless steel coupons with three treatments, 100 ppm and 200 ppm solutions of LAE and water (control); two sub-treatments of high (6 log CFU/ml) and low (4 log CFU/ml) inoculum levels; and two contact times of 5 and 15 min. Attached bacteria were dislodged by vortexing coupons for 1 min with 20 g of 3-mm solid glass beads in 10 ml of 0.1% peptone diluent, and bacterial populations were calculated by plating onto modified oxford medium (MOX) and thin agar layer MOX (TALMOX). The 100 ppm treatment showed average reductions of 1.38 and 2.57 log CFU/coupon at the low inoculum level and 0.37 and 0.62 log CFU/coupon at high inoculum levels, after 5 and 15 min exposure, respectively. For 200 ppm at the high inoculum level, 1.23 and 1.88 log CFU/coupon reductions were seen for 5 and 15 min, respectively; the low inoculum level at 5 and 15 min exposure showed reductions of ≤1.5 log CFU/coupon. The 100 ppm LAE treatment was more effective at low inoculum levels for 5 and 15 min contact times and may be used to control low levels of contamination of L. monocytogenes on food contact surfaces.

Effect of humidity and temperature on the survival ofListeria monocytogeneson surfaces

“…Additionally, survival of L. monocytogenes can be decreased by introducing antimicrobial compounds such as Lauric Arginate into stainless steel ( Saini et al . ), or by coating a stainless steel surface with an antimicrobial film, for example, TiN/Ag (Skovager et al . ).…”

“…Listeria monocytogenes is a pathogenic bacterium, with human disease and infection linked to dairy products, seafood, ready-to-eat meat and raw and undercooked meats. Listeriosis, encompassing bacterial meningitis, sepsis, endocarditis, neonatal abortion and stillbirth in humans (Schlech et al 1983), usually presents in those who are already immunosuppressed, pregnant, old or young (Scholing et al 2007;Barocci et al 2015). During the late 1990s there was a large outbreak of listeriosis linked primarily to consumption of pât e (McLauchlin et al 1991).…”

“…Studies on the interaction between L. monocytogenes and stainless steel, the most common surface used in food preparation, have found that the survival of the microorganism on the surface alters depending on contact time, temperature, nutrients, moisture and the presence of other micro-organisms (Bremer et al 2001;Poimenidou et al 2009;Skovager et al 2013a). Additionally, survival of L. monocytogenes can be decreased by introducing antimicrobial compounds such as Lauric Arginate into stainless steel (Saini et al 2013), or by coating a stainless steel surface with an antimicrobial film, for example, TiN/ Ag (Skovager et al 2013b). However, inert stainless steel is the most suitable for the food industry due to its nontoxic, easy-clean, mechanically stable and corrosion-resistant properties (EHEDG 2004).…”

Hyperspectral imaging of common foodborne pathogens for rapid identification and differentiation

“…It is also very relevant and important to study whether inactive or injured bacterial cells can be differentiated from active and live bacterial cells using HSI (Anderson, Reynolds, Ringelberg, Edwards, & Floey, 2008). Lauric arginate (LAE) is a generally recognized as safe (GRAS) food-grade antimicrobial exhibiting activity against a wide range of pathogens (Saini, Miguel, Marsden, Getty, & Fung, 2013). The LAE has been studied for its use in food as an antimicrobial treatment and as a sanitizer for food contact surfaces (Becerril, Manso, Nerin, & Gómez-Lus, 2013;Saini, 2012).…”

Nanoemulsions of thymol and eugenol co-emulsified by lauric arginate and lecithin

“…These features make LAE a promising antimicrobial preservative to control foodborne pathogens in food systems. Itinhibits a broad spectrum of foodborne pathogens (Ma, Davidson, & Zhong, 2013;Ma, Zhang, & Zhong, 2016;Porto-Fett et al, 2010) and, to date, LAE has been reported in many studies to be a highly efficient antimicrobial agent (Higueras, López-Carballo, Hernández-Muñoz, Gavara, & Rollini, 2013;Noll, Prichard, Khaykin, Sinko, & Chikindas, 2012;Saini, Barrios, Marsden, Getty, & Fung, 2013). In a recent study in our laboratories, the minimum inhibitory concentration (MIC) of LAE for inhibiting Listeria monocytogenes Scott A was found to be 11.8ppm in tryptic soy broth (TSB), while the MIC for Escherichia coli O157:H7 ATCC 43895 or Salmonella Enteritidis was 23.5 ppm (Ma et al, 2013).…”