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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Food Safety and Enteric Pathogens Research » Research » Publications at this Location » Publication #421837

Research Project: Analysis of Genetic Factors that Increase Foodborne Pathogen Fitness, Virulence, and Antimicrobial Resistance Transfer, to Identify Interventions against Salmonella and Campylobacter in Food Animals

Location: Food Safety and Enteric Pathogens Research

Title: Screening novel biocides for rapid killing of Salmonella isolates of concern

Author
item ENCINOSA, MAYA - Oak Ridge Institute For Science And Education (ORISE)
item THOMPSON, LUCAS - Oak Ridge Institute For Science And Education (ORISE)
item Hart-Cooper, William
item Quintanilla Flori, Bruno
item Avena-Bustillos, Roberto
item MEEKS, KEITH - Ipura Food Safety, Inc
item Looft, Torey
item Bearson, Shawn

Submitted to: Conference Research Workers Disease Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/4/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: OBJECTIVE: Salmonella is a human foodborne pathogen that frequently colonizes food animals sub-clinically, resulting in unknowing contamination of food products such as chicken, eggs, turkey, pork and beef. The USDA Food Safety and Inspection Service recently proposed Salmonella as an adulterant in specific poultry products and selected serovars I 4,[5],12:i:-, Enteritidis, Typhimurium, Hadar, and Muenchen as key performance indicators (KPIs) to monitor progress towards the reduction of Salmonella in food products. To decrease Salmonella contamination of processing facilities and poultry products, disinfectants and sanitizers are employed such as Peroxyacetic acid (PAA), an organic peroxide-based compound with a low pH and broad-spectrum bactericidal properties. PAA has a recommended use of 50-2000 ppm depending on product application and has a risk of eye and respiratory irritation at concentrations as low as 5 ppm. Other available disinfectants used in processing facilities include Wexcide, Virkon, and Virocid with recommended dilutions of 1:128 (502 ppm), 1:100 (2291 ppm), and 1:170 (2093 ppm), respectively. With the goal of identifying alternative sanitizers, this study screened and evaluated novel biocides for their ability to rapidly kill Salmonella strains of concern. METHODS: Following an initial screening of 44 new biocide compounds, two biocides (A6 and A16) were selected for further evaluation (along with PAA, Wexcide, Virkon, and Virocid) for their efficacy against five serovars of Salmonella enterica representing serogroup B (Typhimurium and I 4,[5],12:i:-), serogroup C (Infantis and Hadar), and serogroup D (Enteritidis). Overnight cultures of Salmonella were diluted to ~ 1 x 105 CFU/ml and added (equal volumes) to serial two-fold dilutions of each biocide in tap water. After 30 seconds of exposure, reactions were serially diluted (10-fold to 1 X 10-8), plated on LB (Lennox) agar, and grown overnight to determine CFUs present after biocide exposure compared to water-only control samples. CFU counts of Salmonella from biocide treated wells were compared to water control wells using an unpaired T-test to determine the significance of killing at each biocide concentration (p = 0.05). RESULTS: A6 (= 25 ppm), A16 (= 25 ppm), PAA (= 2 ppm), Wexcide (= 80 ppm), Virkon (= 286 ppm), and Virocid (= 111 ppm) significantly reduced CFU counts for all strains when compared to non-treated controls. At 50-100 ppm, the 30 second exposure to A6 and A16 resulted in 100% killing of the five serovars (I 4,[5],12:i:-, Typhimurium, Infantis, Hadar, Enteritidis). Complete killing of the five Salmonella serovars was observed at 2 ppm of PAA, 161-322 ppm of Wexcide, 286-573 ppm of Virkon, and 111 ppm of Virocid. CONCLUSIONS: The efficacy of novel biocides A6 and A16 at low ppm concentrations suggests promising alternative compounds for disinfection of food products, sanitation of food processing surfaces, and potentially improved worker safety.