Efficacy of Warewashing Protocols for Removal of Foodborne Bacteria and Viruses from Utensils in Restaurants and Food Service Establishments

<p>NON-TECHNICAL SUMMARY:<br/> Epidemiological outbreak data have identified five major risk factors related to foodborne outbreaks in retail food establishments. The U.S. FDA Food Code addresses controls for all five, including science-based controls for contaminated equipment. One limitation of the controls related to contaminated equipment is that they only address how to reduce bacteria on food-contact surfaces and not viral agents. Viruses are believed to be responsible for most (60%) foodborne illnesses, of which, more than 90% of the cases are due to norovirus. Studies have shown viruses are highly resistant to current sanitization practices. Not controlling viruses on food-contact surfaces is a significant gap in the current Code, and in the field of food safety. A review of foodborne outbreak data from the past five years citing Salmonella, E. coli, Listeria, and
viruses has determined that food-contact surfaces are most involved in cross-contamination incidences. We propose a controlled-intervention study and will contaminate selected surfaces with E. coli, Listeria, Salmonella and norovirus to compare the effectiveness of two intervention measures used for cleaning purposes. These items will be cleaned using automatic and manual warewashing protocols normally used in restaurants. Cleaning efficacies will be evaluated as a function of sanitizer types, bacterial and viral species, contaminating food types and tableware design. The evaluation will be based on pathogen load remaining on the test items after washing protocols
<p>APPROACH:<br/> Food utensils (plates, drinking glasses, forks, knives, spoons, containers, trays) will be contaminated with various food items inoculated with bacterial (E. coli, L. innocua, or Salmonella) and viral pathogens (TV, MNV, and human norovirus). The food items used will be easily spreadable on the surfaces of these utensils and have different compositions (fat, protein, etc.) to mimic different food soil types. Examples of food items that will be used can include (but are not limited to) water, whole milk, juices, cream cheese, raw fatty meats, raw or cooked eggs, and jellies. Contaminated food items will be applied in specified amounts onto the utensils, and allowed to air dry on sterile racks. Utensils will either be subjected to mechanical or manual warewashing. Sanitizers that will be tested include sodium hypochlorite, peroxyacetic acid, quaternary
ammonium compounds, electrolyzed water, and ozonated water. Washed and dried items will then be subject to microbial sampling. Sterile calcium alginate swabs or sterile sponge swabs will be moistened with maximum recovery diluent and applied to the surface of the cleaned utensils. After removing the swabs, the MRD will be serially diluted in phosphate buffered saline. The sponges are stomached for 2 min, and serial dilutions performed. For bacteria, serial dilutions will be applied to non-selective and selective media. Colonies will be counted and reported as colony forming units (CFU)/tableware item. For TV and MNV plaque assays, serial dilutions of the MRD will be applied to 6-well plates seeded with LLC-MK2 and RAW 264.7 cells, respectively. Virus titer will be reported as log plaque forming units (PFU)/tableware item. The human norovirus will be detected using real-time RT-PCR.
Serially diluted MRD will be subjected to RNA extraction using an RNeasy Mini Kit. Extracted RNA will be loaded onto a 96 well plate, supplemented with RT-PCR reaction mix and primers and fluorescent probes designed to target the VP1 capsid gene of human norovirus, MNV, and TV. Detection of viral RNA will be reported as log copy RNA/ml. The results of this project will be utilized by all three areas of the agricultural knowledge system: research, education, and extension. Determinants of success in the research realm will include peer-reviewed journal publication, presentation at annual professional meetings, feedback from our industrial partner (Hobart Corporation), and statistical analysis of the data collected. For education, the results of this study may be presented at classes taught at OSU. Information about the Food Code, viruses, and the results obtained from this study would be
most beneficial to students interested in food safety. Feedback, improvement, and success will be measured by student evaluation of instruction and by peer-review by invited faculty members. This project will also have an extension impact. The results of this project will be shared with and evaluated by the industry partner Hobart, collaborative restaurants on the OSU Campus, The Ohio Department of Health, and the Conference for Food Protection (CFP).
PROGRESS: 2012/08 TO 2013/08Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Objective 1: Continue manual warewashing studies with Listeria innocua, Escherichia coli K12, and murine norovirus 1 (MNV-1) Manual warewashing studies will also include stainless steel forks (contaminated with 0.5 g cream cheese) and drinking glasses (contaminated with 0.5 ml of contaminated milk) Mechanical dishwashing and sanitization studies (with plates, forks, and drinking glasses using the above food soils and organisms) will also be conducted to compare how well the two washing procedures will
remove microorganisms from food utensils Objective 3: Continue evaluating the use of AEW and NEW as an alternative sanitizer against bacteria and viruses Attempt to use existing ozone-generators at the OSU Food Science Department to generate ozonated water for use as another alternative sanitizer Objective 4: One to two manuscripts will be prepared for submission to journals such as Applied and Environmental Microbiology, Journal of Food Protection, Food Control, International Journal of Food Microbiology, or Journal of Food Science The project director will also plan to attend conferences to disseminate research findings to peers (academics, industry professionals) via poster or oral presentation at the International Association for Food Protection Annual Meeting (August 3-6, Indianapolis, IN) and/or the Institute of Food Technologists Annual Meeting and Food Expo (June 21-24, New
Orleans, LA). Abstracts for these conferences will be submitted in December 2013 or January 2014. The project director will also share their research findings at the Conference for Food Protection Biennial Meeting (May 1-7, Orlando, FL). Objective 5: The project director will provide lectures about the Food Code and their research findings to the Food Regulations class, taught at OSU. Unfortunately, the Food Safety and Public Health and Advanced Food Microbiology 2 courses are not being offered for the upcoming semester. The project director will work with his mentors and department faculty to find alternate courses in which to present these lectures.