Efficacy of Selected Powdered Floor Treatments against Salmonella, Escherichia coli, and Listeria Monocytogenes on Polyurethane-Concrete Flooring Material Carriers

Abstract

Food processing environment flooring can become contaminated with pathogens in many ways, including foot and equipment traffic, incoming materials, and floor drain backups. Natural antimicrobial turmeric and commercially available powdered floor treatments may reduce the levels of pathogens on flooring, thereby reducing the risk of cross-contamination from the floor to food contact surfaces. These chemicals were evaluated to determine their effectiveness against cocktails of Salmonella, Escherichia coli, and Listeria monocytogenes dried onto the surfaces of carriers made from polyurethane-concrete commercial flooring material. Aqueous test solutions, diluted in sterile water, were prepared from the minimum treatment required per square meter from the manufacturer's instructions. Potential synergy between turmeric and a percarbonate-based commercial floor treatment was explored with a mixture of turmeric and sodium percarbonate (SPC), each at approximately 37 g/m2 application rate. Each inoculated carrier was exposed to the treatment solutions or a sterile water control for 10 min at room temperature and neutralized with HiCap Neutralizing Broth; the bacteria were suspended and enumerated, and log reductions calculated for each treatment and inoculum combination. Mean log CFU per carrier reductions with standard deviations ranged between 4.29 ± 0.34 for the SPC-based treatment and 0.004 ± 0.23 for turmeric for Salmonella, 4.81 ± 0.16 for SPC-based treatment and −0.16 ± 0.62 for turmeric for E coli, and 4.88 ± 0.6 for SPC-based treatment and −0.16 ± 0.15 for turmeric for L. monocytogenes. The results support that among the treatments tested, those containing SPC were more effective, turmeric alone was less effective, and a percarbonate treatment containing turmeric was not more effective than the commercial treatment alone at half the recommended application rate against the organisms tested.