The Efficacy of Ware-Washing Protocols for Removal of Foodborne Viruses from Utensils in Restaurants and Food Service Establishments
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The efficacy of ware-washing protocols for removal of foodborne viruses from utensils in restaurants and food service establishments DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Lizanel Feliciano, M.S. Graduate Program in Food Science and Technology The Ohio State University 2012 Dissertation Committee: Dr. Melvin A. Pascall, Advisor Dr. Jianrong Li Dr. Hua Wang Dr. Gerald S. Frankel Copyrighted by Lizanel Feliciano 2012 ABSTRACT Food contact surfaces may present a potential health hazard if they are not properly cleaned and sanitized. Contaminated surfaces (e.g. utensils, cutting boards, equipment) have been identified as sources of cross-contamination for food during preparation and when being served to consumers. Therefore, ensuring effective cleaning and sanitization of food contact surfaces may help in the spread of foodborne pathogens and incidence of outbreaks. The FDA Food Code and NSF International standards mandate that all surfaces/tableware items should be free of food soils and that a minimum microbial reduction of 5 logs must be obtained before surface sanitization could be considered effective. To comply with these standards, food service establishments must clean and sanitize food contact surfaces either manually or mechanically. Unfortunately, the standards set for these ware-washing methods specifically address the reduction of bacterial numbers from food contact surfaces, and not viruses. Therefore, information regarding the effectiveness of these standards against viruses needs to be elucidated. The first part of this dissertation (Chapter 2) compared the efficacy of sodium hypochlorite (chlorine) and quaternary ammonium compound (QAC) in reducing bacterial populations (Escherichia coli K-12 and Listeria innocua) and murine norovirus (MNV-1) counts on different food contact surfaces (ceramic plates, stainless steel forks and drinking glasses). Each microorganism was separately inoculated into 2% reduced fat UHT milk and cream ii cheese spread. The milk was used to contaminate the drinking glasses and the spreadable cream cheese was used on the ceramic plates and forks. All tableware items were manually and mechanically washed and sanitized. Bacterial and viral counts were then determined on the surface of each tableware item using the plaque assay and plate count methods, respectively. This study found that QAC and sodium hypochlorite sanitizers had the ability to produce ≥ 5 log reductions on both E. coli and L. innocua in manual and mechanical ware-washing operations. However, they were unable to produce the same level of antiviral activity (≤ 3 logs) under similar conditions irrespective of the nature of the tableware item and the ware-washing protocol. The second part of this dissertation (Chapter 3) evaluated the efficacy of the manual and mechanical ware-washing protocols to remove caliciviruses from food contact surfaces (ceramic plates, stainless steel forks and drinking glasses). Porcine sapovirus (PoSaV) was used as a surrogate for both noroviruses (NoVs) and sapoviruses (SaVs). The tableware items were contaminated with the milk (drinking glasses) and cream cheese spread (ceramic plates and forks) inoculated with PoSaV. These were manually and mechanically washed and sanitized with different sanitizing solutions (chlorine and QAC). Tap water was used as the control sanitizing solution. After the ware-washing operations, the viral counts on the surfaces were determined by 50% tissue culture infective dose (TCID50). The chlorine sanitizer was able to reduce PoSaV by approximately 2 logs when exposed to higher temperatures during mechanical ware- iii washing (49ºC vs. 43ºC during manual ware-washing). The viral reductions achieved with the other sanitizers (QAC and control) were not significant (< 1 log). The third part of this dissertation (Chapter 4) investigated the effect of different sanitizers [chlorine-based sanitizers (bleach and Chlor-Clean), QAC and tap water] on their abilities to remove milk samples from underlying ceramic and glass surfaces. Three types of milk samples were tested in this study: 1) plain milk; 2) milk inoculated with MNV-1; and 3) milk inoculated with PoSaV. Atomic force microscopy (AFM) was used to determine the thicknesses of the milk films left after the surfaces were mechanically washed and sanitized. Results from this study suggested that milk samples contaminated with viruses tend to adhere to a greater extent (thicker films) than non-contaminated milk and that common sanitizing solutions (chlorine-based and QAC sanitizers) appeared not to effectively remove milk-virus deposits from simulated food contact surfaces. iv DEDICATION To my family and my friend Edgardo J. Díaz Polo, who lost his battle against cancer. v ACKNOWLEDGMENTS I want to start thanking God for all His help and love all this time. I would like to thank my advisor Dr. Melvin Pascall for his dedication, support and guidance during these past years. I would also like to thank Dr. Jianrong Li, Dr. Hua Wang and Dr. Gerald Frankel for being part of my committee members. Dr. Jaesung Lee, special thanks to you for helping me during many difficult times. I would like to acknowledge Paul Courtright for his assistance and willingness to help at all times. Thanks Paul, you are the best! I would also like to acknowledge Joel Hipp and Tom Gruesser from Hobart Corporation for their technical assistance during this research project. Also, I would like to acknowledge the National Center for Research Resources for their financial support (Award Number UL1RR025755). Finally, I want to thank my family and friends for their unconditional love, support and prayers during this learning and challenging experience. vi VITA May 2002 .......................................................Eduardo García Carrillo High School 2002-2007 ......................................................B.S. Animal Industry, University of Puerto Rico- Mayagüez Campus 2007-2009 ......................................................M.S. Food Science and Technology, The Ohio State University 2009 to present ..............................................Graduate Research Associate, Department of Food Science and Technology, The Ohio State University PUBLICATIONS 1. Feliciano, L, Lee, J and Pascall, MA. 2012. Transmission electron microscopic analysis showing structural changes to bacterial cells treated with electrolyzed water and an acidic sanitizer. Journal of Food Science, 77:M182-M187. 2. Pascall, MA, Feliciano Sanchez, L. 2010. Smart packaging technology as a food safety tool. Proceedings from the VI. International Packaging Congress. September 2010. Istanbul Turkey. The ASD Turkish Packaging Manufacturing Association. Istanbul, Turkey. Vol 1. p. 225-234. 3. Feliciano, L, Lee, J, Lopes, J and Pascall, MA. 2010. Efficacy of sanitized ice in reducing bacterial load on fish fillet and in the water collected from the melted ice. Journal of Food Science, 100:1M231-M239. vii 4. Tournas, VH, Feliciano, L and Katsoudas, EJ. 2010. Evaluation of the petrifilm dry rehydratable film for the enumeration of yeasts and moulds in naturally contaminated foods. Journal of Food Safety, 30:506-514. 5. Gunawan, AM, Park, SK, Pleitner, JM, Feliciano, L, Grant, AL, and Gerrard, DE. 2007. Contractile protein content reflects myosin heavy-chain isoform gene expression. Journal of Animal Science, 85:1247-1256. FIELDS OF STUDY Major Field: Food Science and Technology viii TABLE OF CONTENTS Page ABSTRACT………………………………………………………………………...... ii DEDICATION……………………………………………………………………….. v ACKNOWLEDGEMENTS………………………………………………………… vi VITA………………………………………………………………………………….. vii LIST OF FIGURES………………………………………………………………….. xv LIST OF TABLES…………………………………………………………………… xvii 1. LITERATURE REVIEW………………………………………………………… 1 1.1. Foodborne illnesses: Microorganisms of public health concern, their prevalence and challenges…………………………………………………. 1 1.2. Viruses: important foodborne illness agents…………………………………….. 6 1.2.1. Introduction to viruses………………………….………………………….. 7 1.2.2. Structure: non-enveloped and enveloped viruses………………………....... 8 1.3. Foodborne viruses of importance………………………………………………… 9 1.3.1. Hepatitis E virus ……..……………………………………………….......... 9 1.3.2. Hepatitis A virus ……...………………………………………..…….......... 10 1.3.3. Human Rotavirus ……...…………………………………………………... 11 1.3.4. Human Norovirus ……...………………………………………………….. 12 ix 1.3.4.1. Transmission routes…………………………………….…………. 14 1.3.4.2. NoV infection: replication and cell growth……………………….. 14 1.3.4.3. Murine Norovirus 1 (MNV-1) as a surrogate……………………... 16 1.3.5. Human Sapovirus (SaV)…………………………………………………………. 16 1.3.5.1. Transmission routes……………………………………………….. 17 1.3.5.2. SaV infection: replication and cell growth………………………… 18 1.3.5.3. Porcine Sapovirus as a surrogate………………………………….. 18 1.4. Foodborne illness risk factors associated with restaurants and food service establishments……………………………………………………… 19 1.4.1. Cleaning and sanitization of food contact surfaces………………………… 20 1.4.2. Surfaces…………………………………………………………………….. 20 1.4.3. Types of soils………………………………………………………………. 22 1.4.4. Cleaning agents…………………………………………………………….. 24 1.4.4.1. Surfactants………………………………………………………….. 25 1.4.4.1.1. Soaps……………………………………………………... 26 1.4.4.1.2. Detergents (synthetic detergents)……………………....... 27 1.4.4.2. Acid cleaning agents………………………………………………. 28 1.4.4.3. Alkaline cleaning agents…………………………………………... 28 1.4.5. Sanitizing agents…………………………………………………………... 30 1.4.5.1.