Inactivation of Bacillus anthracis Spores by Liquid Biocides in the Presence of Food Residue

Abstract

Biocide inactivation of Bacillus anthracis spores in the presence of food residues after a 10-min treatment time was investigated. Spores of nonvirulent Bacillus anthracis strains 7702, ANR-1, and 9131 were mixed with water, flour paste, whole milk, or egg yolk emulsion and dried onto stainless-steel carriers. The carriers were exposed to various concentrations of peroxyacetic acid, sodium hypochlorite (NaOCl), or hydrogen peroxide (H 2 O 2 ) for 10 min at 10, 20, or 30°C, after which time the survivors were quantified. The relationship between peroxyacetic acid concentration, H 2 O 2 concentration, and spore inactivation followed a sigmoid curve that was accurately described using a four-parameter logistic model. At 20°C, the minimum concentrations of peroxyacetic acid, H 2 O 2 , and NaOCl (as total available chlorine) predicted to inactivate 6 log 10 CFU of B. anthracis spores with no food residue present were 1.05, 23.0, and 0.78%, respectively. At 10°C, sodium hypochlorite at 5% total available chlorine did not inactivate more than 4 log 10 CFU. The presence of the food residues had only a minimal effect on peroxyacetic acid and H 2 O 2 sporicidal efficacy, but the efficacy of sodium hypochlorite was markedly inhibited by whole-milk and egg yolk residues. Sodium hypochlorite at 5% total available chlorine provided no greater than a 2-log 10 CFU reduction when spores were in the presence of egg yolk residue. This research provides new information regarding the usefulness of peroxygen biocides for B. anthracis spore inactivation when food residue is present. This work also provides guidance for adjusting decontamination procedures for food-soiled and cold surfaces.

Research and Development of On-site Decontamination System for Biological and Chemical Warfare Agents

“…Also, if spores are included in the food stuff, efficiency of wet decontamination is diminished. 58) Treatment using chemical modifier, high pressure and high temperature is enough to decontaminate BCWAs through destruction of toxic and infectious machinery, and it is not necessary to destroy the targets completely to convert to the broken pieces. If the perfect destruction of BCWAs is desired, perfect oxidation can be performed to convert to carbon dioxide, water, nitric acid, sulfuric acid etc.…”

Efficacy of Chlorine, Chlorine Dioxide, and Peroxyacetic Acid in Reducing Salmonella Contamination in Wash Water and on Mangoes Under Simulated Mango Packinghouse Washing Operations

“…When employed as a wash water disinfectant, chlorine dioxide has been applied at 5 ppm in water to keep the residue concentration on washed produce within the approved 3-ppm limit [US Food Drug Administration (USFDA) and Center for Food Safety Applied Nutrition, 1998;Pao et al, 2009;21 CFR 173.300]. Peroxyacetic acid (PAA) has been shown to be effective against foodborne pathogens on different produce surfaces (Hilgren et al, 2007;Vandekinderen et al, 2009). Further, it is approved for use in produce wash water at a maximum permissible limit of 80 ppm (21CFR173.315).…”

“…Commercially available peracetic acid-based disinfectants contain a considerable amount of hydrogen peroxide that also exhibits antimicrobial activity. PAA is not susceptible to peroxidases and is known to retain its antimicrobial activity in the presence of organic loads or food residues when compared to chlorine (Fatemi and Frank, 1999;Hilgren et al, 2007;Small et al, 2007). Although antimicrobial, the oxidizing ability of these disinfectants, particularly chlorine dioxide and PAA are also associated with discoloration and negative impact on fruit color (Wang et al, 2007;Du et al, 2009;Joshi et al, 2013;Van de Velde et al, 2016;Chen, 2017).…”

Principles and Practice of Disinfection of Biological Warfare Agents – How Clean is Clean Enough?

“…This phenomenon applies in particular to oxidative biocides but also the activity of phenols is reduced by organic material like soil, serum, fecal material, and food residues. It has been shown that organic matter decreases the effect of hypochlorites against bacteria, viruses, and fungi [27]. Moreover, body fluids like blood serum can reduce biocide efficacy by neutralizing active agents.…”