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. col, S. enterica, and L. monocytogenes growth. The minimum reduction at 3 s and 5 s exposure for both intensities was 99.95-100% for E. coli, 98.36-100% for S. enterica, and 99.24-100% for L. monocytogenes. The 1 s exposure time resulted in lower efficiency in reducing bacterial growth, with survival rates of 0.48-6.95% for E. coli, 0.29-17.40% for S. enterica, and 1.95-31.8% 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.
","abstract_html":"<p>Foodborne pathogens, including <em>Escherichia coli</em>, <em>Salmonella enterica</em>, and <em>Listeria monocytogenes,</em> 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 <em>E. coli; </em>enterohemorrhagic <em>E. coli </em>(EHEC) O157:H7; enterotoxigenic <em>E. coli</em> (ETEC) O78:H11;<em> S. enterica</em> serotypes Enteritidis, Newport, Typhimurium, and Javiana; and <em>L. monocytogenes </em>serotypes 1/2a, 1/2b, and 4b<em>.</em> Each bacterial strain was spread-plated on non-selective agar and exposed to high-intensity (10 mW/cm<sup>2</sup>) or low-intensity (5 mW/cm<sup>2</sup>) 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/cm<sup>2</sup> or low: 5 mW/cm<sup>2</sup>) resulted in effective and consistent inhibition of <em>E. col,</em> <em>S. enterica, </em>and <em>L. monocytogenes</em> growth. The minimum reduction at 3 s and 5 s exposure for both intensities was 99.95-100% for <em>E. coli</em>, 98.36-100% for <em>S. enterica</em>, and 99.24-100% for <em>L. monocytogenes</em>. The 1 s exposure time resulted in lower efficiency in reducing bacterial growth, with survival rates of 0.48-6.95% for <em>E. coli</em>, 0.29-17.40% for <em>S. enterica</em>, and 1.95-31.8% for <em>L. monocytogenes</em>. 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 <em>E. coli, S. enterica, </em>and <em>L. monocytogenes</em>.</p>","abstract_has_math":false,"creators":["McCoy Sanders, Jennifer"],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Thesis","degree_discipline":"Food Science","degree_department":null,"school":null,"contributors":["Rosalee Hellberg, Ph.D.","Lillian Senger, Ph.D.","Anuradha Prakash, Ph.D."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2023,"date_issued":"2023-12-01T08:00:00Z","date_published":"2023-12-01T08:00:00Z","updated_at":"2026-07-24T01:38:31Z","subjects":["Contamination Sanitization Inspection and Disinfection (CSI-D)","disinfection","foodborne bacteria","light-emitting diode (LED)","ultraviolet (UV)","Food Microbiology","Food Science"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.chapman.edu/food_science_theses/32","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Rosalee Hellberg, Ph.D.","Lillian Senger, Ph.D.","Anuradha Prakash, Ph.D."]},{"key":"dc:creator","label":"Author","values":["McCoy Sanders, Jennifer"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2025-09-26T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Food Science"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Contamination Sanitization Inspection and Disinfection (CSI-D)","disinfection","foodborne bacteria","light-emitting diode (LED)","ultraviolet (UV)","Food Microbiology","Food Science"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.chapman.edu/food_science_theses/32"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["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. col, S. enterica, and L. monocytogenes growth. The minimum reduction at 3 s and 5 s exposure for both intensities was 99.95-100% for E. coli, 98.36-100% for S. enterica, and 99.24-100% for L. monocytogenes. The 1 s exposure time resulted in lower efficiency in reducing bacterial growth, with survival rates of 0.48-6.95% for E. coli, 0.29-17.40% for S. enterica, and 1.95-31.8% 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.
"]},{"key":"dc:source","label":"Dc Source","values":["McCoy Sanders, J. (2023). Disinfection of foodborne bacteria using the Contamination Sanitization Inspection and Disinfection (CSI-D) device. Master's thesis, Chapman University. https://doi.org/10.36837/chapman.000509"]},{"key":"dc:title","label":"Title","values":["Disinfection of Foodborne Bacteria using the Contamination Sanitization Inspection and Disinfection (CSI-D) Device"]}]}],"canonical_facts":{"dc:contributor":["Rosalee Hellberg, Ph.D.","Lillian Senger, Ph.D.","Anuradha Prakash, Ph.D."],"dc:creator":["McCoy Sanders, Jennifer"],"dc:date.available":["2025-09-26T07:00:00Z"],"dc:description.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. col, S. enterica, and L. monocytogenes growth. The minimum reduction at 3 s and 5 s exposure for both intensities was 99.95-100% for E. coli, 98.36-100% for S. enterica, and 99.24-100% for L. monocytogenes. The 1 s exposure time resulted in lower efficiency in reducing bacterial growth, with survival rates of 0.48-6.95% for E. coli, 0.29-17.40% for S. enterica, and 1.95-31.8% 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.
"],"dc:identifier":["https://digitalcommons.chapman.edu/food_science_theses/32"],"dc:source":["McCoy Sanders, J. (2023). Disinfection of foodborne bacteria using the Contamination Sanitization Inspection and Disinfection (CSI-D) device. Master's thesis, Chapman University. https://doi.org/10.36837/chapman.000509"],"dc:subject":["Contamination Sanitization Inspection and Disinfection (CSI-D)","disinfection","foodborne bacteria","light-emitting diode (LED)","ultraviolet (UV)","Food Microbiology","Food Science"],"dc:title":["Disinfection of Foodborne Bacteria using the Contamination Sanitization Inspection and Disinfection (CSI-D) Device"],"thesis:degree_discipline":["Food Science"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T01:38:31Z"}