Title: Inactivation of F.tularensis Utah-112 on food and food contact surfaces by ultraviolet light Authors
Submitted to: Journal of Food Processing and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 27, 2012
Publication Date: November 5, 2012
Citation: Sommers, C.H., Scullen, B.J., Paoli, G., Bhaduri, S. 2012. Inactivation of F.tularensis Utah-112 on food and food contact surfaces by ultraviolet light. Journal of Food Processing and Technology. doi:10.4172/2157-7110.S11-002. Interpretive Summary: Francisella tularensis causes a plague-like illness which can be contracted through consumption of contaminated food and water as well as the processing of diseased animals. Ultraviolet light (UV-C) technology is a US Food and Drug Administration approved technology which can be used to decontaminate food and food contact surfaces. In this study we investigated the ability of UV-C to inactivate Francisella tularensis Utah-112(a rodent pathogen)on agar plates, stainless steel, plastic, and foods. The D-10 value, the UV-C dose needed to inactivate 90% of the microorganism, for Utah-112 on agar plates was 0.71 mJ/cm2. We found that UV-C almost completed inactivated (over 99.99999%) of Utah-112 suspended in the fluid exudate (drip) from meat, processed meat, and fish placed on stainless steel and plastic surfaces at a UV-C dose of 1 J/cm2 using a commercial UV-C conveyor. UV-C (1 J/cm2) inactivated over 50% of Utah-112 on beef steak pieces, boneless skinless chicken breasts, and catfish fillets. Approximately 99% of the microorganism was inactivated on hot dog and bratwurst surfaces. This research provides guidance to federal action agencies for UV-C control of F. tularensis and will help food processors protect their workers and consumers from tularemia.
Technical Abstract: Francisella tularensis is the causative agent of tularemia, a plague-like illness that affects animals and humans, and has caused large illness pandemics in the last century. It has also been used as a biological warfare agent, and tularemia can be contracted through consumption of contaminated food and water. In this study the use of a U.S. Food and Drug Administration approved technology, 254 nm ultraviolet light (UV-C), to inactivate F. tularensis Utah-112 (a rodent pathogen) on food and food contact surfaces was investigated. The D-10 value, the UV-C dose needed to inactivate one log of microorganism, was approximately 0.71 mJ/cm2 on agar plates using a low UV-C intensity of 100 uW/cm2/s. When a commercial UV-C conveyor was used (5 mW/cm2/s) 0.5 J/cm2 inactivated >7 log CFU of F. tularensis Utah 121 on agar plates. At 0.5 J/cm2 UV-C inactivated >4 log CFU of Utah-112 in beef, chicken, catfish, frankfurter, and bratwurst exudates inoculated onto stainless steel coupons , and >7 log CFU was eliminated at 1 J/cm2 UV-C. Similar results were obtained when the exudates were inoculated onto high density polypropylene. Approximately 0.5 log CFU was inactivated on chicken breast, beef steak, and catfish fillets, and approximately 1.9 log CFU on frankfurters and bratwurst at a UV-C dose of 1 J/cm2. These results indicate routine use of UV-C during food processing would provide workers and consumers some protection against F. tularensis.