Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/15/2014
Publication Date: 8/3/2014
Citation: Lacombe, A.C., Niemira, B.A., Gurtler, J. 2014. Surfactant enhanced disinfection of the human norovirus surrogate, tulane virus with organic acids and surfactant. Meeting Abstract. Volume 1, Page 1., IAFP Annual Meeting., Indianapolis, Indiana., August 3-6, 2014
Technical Abstract: Human infection with foodborne viruses can occur following consumption of contaminated food, person-to-person body contact, or release of aerosols. Combinatorial treatments of surfactants and organic acids may have synergistic or additive mechanisms to inactivate foodborne viruses and prevent outbreaks. The purpose of this experiment is to investigate the efficacy of treatments of lactic (LA) or acetic acid (AA) in combination with sodium dodecyl sulfate (SDS) against a human norovirus surrogate, Tulane virus (TV). An aqueous 4 percent (v/v) stock solution of LA or AA with 5.6 percent (v/v) SDS was adjusted to pH 2, 4 or 7 with approximately 0.5 ml of 0.1M NaOH. The stock solution was diluted to 2x of its desired concentration with growth media (M119 + 10 percent FBS). The solution was inoculated with 6 log PFU/ml of TV with a treatment time of 5 minutes. Because of the capacity of the growth media, pH of the final solution was measured after the treatment time. The survival of TV was quantified using a plaque assay with LLC-MK2 cells. The minimum concentration of treatments that produced significant (P < 0.05) log reduction of TV was 0.5/0.7 percent (v/v) LA/ SDS at pH 3.5 (4.5 PFU/ml reduction), 1.0/1.4 percent (v/v) LA/SDS at pH 4.2 (2.2 log PFU/ml reduction), and 0.5/0.7 percent (v/v) AA/SDS at pH 4.0 (2.6 log PFU/ml reduction). The combinatorial treatment of AA or LA with SDS at pH > 5 did not produce significant log reduction. No log reduction was observed with treatments of either AA, LA, or SDS alone at pH 2. This experiment demonstrates that surfactant like SDS aid in the organic acid toxicity against viruses. However, inactivation of TV by combinatorial treatments is contingent upon the sanitizing solution’s pH being below the pKa of the organic acid being used. This information can be used to develop sanitizing washes to disinfect food contact surfaces.