Disinfection of foodborne bacteria using the Contamination Sanitization Inspection and Disinfection (CSI-D) device bg

Authors: SANDERS, JENNIFER MCCOY - Chapman University; ALARCORN, VANESSA - Chapman University; MARQUIS, GRACE - Chapman University; TABB, AMANDA - Chapman University; Van Kessel, Jo Ann; Sonnier, Jakeitha - Jackie; Haley, Bradd; Baek, Insuck; Qin, Jianwei - Tony Qin; Kim, Moon; VASEFI, FARTASH - Safetyspect Inc; SOKOLOV, STANISLAV - Safetyspect Inc; HELLBERG, ROSALEE - Safetyspect Inc

Submitted to: Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2024
Publication Date: 4/29/2024
Citation: Sanders, J., Alarcorn, V., Marquis, G., Tabb, A., Van Kessel, J.S., Sonnier, J.L., Haley, B.J., Baek, I., Qin, J., Kim, M.S., Vasefi, F., Sokolov, S., Hellberg, R. 2024. Disinfection of foodborne bacteria using the Contamination Sanitization Inspection and Disinfection (CSI-D) device bg. Food Microbiology. 10(9): Article e30490. https://doi.org/10.1016/j.heliyon.2024.e30490.
DOI: https://doi.org/10.1016/j.heliyon.2024.e30490

Interpretive Summary: Foodborne pathogens are major causes of gastrointestinal disease in the US and globally. Three common pathogenic bacteria known to cause foodborne outbreaks with a variety of health complications are Escherichia coli, Salmonella enterica, and Listeria monocytogenes. Proper disinfection and sanitization of food contact surfaces has been shown to prevent the spread of bacteria by reducing surface contamination by 72-100%. Traditional cleaning methods are effective, but they can lead to further contamination of surfaces if not used properly and are time-consuming. The Contamination Sanitization Inspection and Disinfection (CSI-D) device is a new handheld fluorescence-based imaging system designed to disinfect food contact surfaces contaminated with microorganisms using ultraviolet-C (UVC) illumination. The goal of this study was to determine the optimal parameters for the disinfection of foodborne bacteria using the CSI-D device. The study was conducted with generic (non-pathogenic) E. coli, two pathogenic E. coli: enterohemorrhagic E. coli (EHEC) O157:H7; enterotoxigenic E. coli (ETEC) O78:H11; four serotypes of Salmonella: Enteritidis, Newport, Typhimurium, and Javiana; and four L. monocytogenes serotypes: 1/2a, 1/2b, and 4b. Each bacterial strain was spread-plated on non-selective agar media and exposed to high-intensity (10 mW/cm2) or low-intensity (5 mW/cm2) UVC for 1 s, 3 s, or 5 s or were not exposed to UVC (control). The plates were then incubated overnight at 37' and the resulting colonies were counted. Three trials for each bacterial strain were conducted on separate days. The average of the trials showed that exposure time of 3-5 s at either intensity (high: 10 mW/cm2 or low: 5 mW/cm2) resulted in effective and consistent inhibition of E. coli, S. enterica, and L. monocytogenes growth. The minimum reduction at 3 s and 5 s exposure for both intensities was 100% for E. coli, 98.4-100% for S. enterica, and 99.2-100% for L. monocytogenes. The 1 s exposure time showed inconsistent results, with survival rates of 0.5-7.0% for E. coli, 0.3-17.4% for S. enterica, and 2.0-31.8% for L. monocytogenes. The results of this study show that, in pure culture conditions, exposure to UVC with the CSI-D device for at least 3 s is required to achieve 98-100% reduction of E. coli, S. enterica, and L. monocytogenes. Because this work was conducted in laboratory conditions with pure cultures, further research is needed to determine if the parameters found to be effective in this study can be applied to reduce bacterial growth on food contact surfaces. The results can be used by industry personnel to evaluate new ways for mitigation of food contamination with pathogenic bacteria.

Technical Abstract: Foodborne pathogens, including Escherichia coli, Salmonella enterica, and Listeria monocytogenes, are major causes of gastrointestinal disease globally. The Contamination Sanitization Inspection and Disinfection (CSI-D) device is a new handheld fluorescence-based imaging system designed to disinfect food contact surfaces contaminated with microorganisms using ultraviolet-C (UVC) illumination. This study aimed to determine the optimal parameters for the disinfection of foodborne bacteria using the CSI-D device. The following bacterial strains were tested: generic E. coli; enterohemorrhagic E. coli (EHEC) O157:H7; enterotoxigenic E. coli (ETEC) O78:H11; S. enterica serotypes Enteritidis, Newport, Typhimurium, and Javiana; and L. monocytogenes serotypes 1/2a, 1/2b, and 4b. Each bacterial strain was spread-plated on non-selective agar and exposed to high-intensity (10 mW/cm2) or low-intensity (5 mW/cm2) UVC for 1 s, 3 s, or 5 s or were not exposed to UVC (control). The plates were then incubated overnight at 37' and the resulting colonies were counted. Three trials for each bacterial strain were conducted on separate days. The average of the trials showed that exposure time of 3-5 s at either intensity (high: 10 mW/cm2 or low: 5 mW/cm2) resulted in effective and consistent inhibition of E. coli, S. enterica, and L. monocytogenes growth. The minimum reduction at 3 s and 5 s exposure for both intensities was 100% for E. coli, 98.4-100% for S. enterica, and 99.2-100% for L. monocytogenes. The 1 s exposure time showed inconsistent results, with survival rates of 0.5-7.0% for E. coli, 0.3-17.4% for S. enterica, and 2.0-31.8% for L. monocytogenes. The results of this study show that, in pure culture conditions, exposure to UVC with the CSI-D device for at least 3 s is required to achieve 98-100% reduction of E. coli, S. enterica, and L. monocytogenes.