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July 2015 | Volume 3, Issue 3

STEC CAP News CONTROLLING SHIGA TOXIN-PRODUCING E. coli TO IMPROVE BEEF SAFETY

Director’s Update findings to our regulatory and industry partners who have already put these results into practice. I/we want to especially extend our appreciation to Jeanette Thurston for her continued guidance and unwavering support of our people and programs. It was also great to have the continued support of the highest level of administrators at both Kansas State University and the University of Nebraska – Lincoln. Special thanks to Drs. Archie Clutter and Deb Hamernik for making the trip from Lincoln and to Drs. April Mason, Karen Burg, and John Floros from KSU who so warmly welcomed us and supported our conference. Special thanks also to Jill Hochstein, Carol Farnham, and their extended teams at KSU and UNL for organizing and hosting this conference. Job well done folks!

John Luchansky

G

reetings fellow STEC CAPpers. It’s hard to believe that summer 2015 is about half over and that the fall semester is just around the corner already. I hope it has been an enjoyable and productive summer for everyone thus far. I have only a handful of topics to comment on for this edition of the newsletter. For starters, our 3rd STEC CAP Annual Meeting last month in “The Little Apple” (aka Manhattan, KS) was well attended and by all accounts was very successful. Highlights included informative breakout sessions for each of our 5 objective teams, very constructive feedback from our stakeholder advisory board, lively social gatherings, another excellent student poster session, an unique and impactive initiative to develop curriculum centered around problem based learning and training of both educators and the next generation of food safety professionals, and some outstanding presentations that really showcased the collaborative and multi-institutional and multi-disciplinary research that we are conducting. From the presentations, networking, and publications it is quite evident that we continue to address the highest priority research topics related to lowering the public health risk of STEC attributable to beef, and that we have made considerable progress towards disseminating our

My STEC CAP Experience

Next, on behalf of the entire EMT I want to take a moment and thank everyone for creating a personal Piestar account. Piestar is our new web-based data collection and reporting system

...continued page 5 STEC CAP Team 126D VBS Lincoln, NE 68905 PHONE: 402-472-8564 FAX: 402-472-9690

stecbeefsafety.org

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t was clear from the very beginning that my Ph.D. experience would be unique. I had already spent two years working with Ben Chapman on my Master’s degree and so I knew I was in for a few more years of foodborne illness stories, risk communication, and hockey references. What I didn’t realize at the time was the other incredible opportunities I would receive by working on the STEC CAP grant. Ben explained the goals of my research project as part of the STEC CAP grant: analyzing restaurant servers’ risk communication about undercooked hamburgers. In other words, ordering a bunch of hamburgers at a bunch of restaurants and asking a bunch of questions about them. The project idea was loosely defined and I was free to proceed with research design as I saw fit and make the project my own. Taking on such an unique project gave me great experience in designing qualitative research methods. Most graduate students do not enjoy the benefit of interacting with such a large and diverse group of experts in their field of study. Over the course of my Ph.D., I worked with STEC CAP grant collaborators and graduate

...continued page 6 Inside this issue Director’s Update ........................................................... 1 Student Perspective....................................................... 1 Electrostatic Spray Technologies............................ 2 Award Winners................................................................. 4 Education Award............................................................. 6 STEC CAP Breakfast........................................................ 7


STEC CAP News Possible Applications for Electrostatic Spray Technologies to Reduce Shiga-Toxigenic Escherichia coli (STEC) on Beef Carcasses and Subprimals

Jessica Hudson, Katie Kirsch, Tamra Tolen, T. Mathew Taylor and Alejandro Castillo* Department of Animal Sciences, Texas A&M University, College Station, TX Introduction

For decades, the meat industry has been developing and implementing post-harvest interventions to reduce bacterial pathogens on beef products including carcasses, subprimals, and trimmings etc. These interventions have acquired new relevance in the reduction of STEC since six serogroups of non-O157 E. coli (O26, O45, O103, O111, O121, and O145) have been declared adulterants in raw, non-intact beef products or components in addition to E. coli O157:H7. All these serogroups are referred to as STEC-7 or the Big 7. In a multi-institutional project (STEC-CAP), researchers at various universities are conducting studies to validate current and novel interventions for effectiveness at reducing STEC, and to develop improved

methods for applying these interventions. The STEC-CAP team at Texas A&M University, composed of Drs. Gary Acuff, Alex Castillo, Davey Griffin, Matt Taylor and their staffs, has been studying the efficacy of chemical and biological interventions, as well as the effectiveness of a hand-held electrostatic spray system (ESS), to reduce STEC populations on chilled beef. Dr. Castillo is working with a hand-held ESS to apply antimicrobials, while Dr. Taylor is testing its potential benefits in delivering biocontrol agents. Biopreservatives such as the lactic acid bacteria (LAB) have been reported in the literature to achieve pathogen reduction on fresh beef products via the secretion of chemical compounds including organic acids, peroxides, and antimicrobial polypeptides.


STEC CAP News Unlike conventional spraying, solutions are atomized into electrically charged droplets. The atomized solution is electrostatically attracted to all surfaces of the meat. In addition, the electrically charged small droplet size may reduce the volume of treatment solutions required to achieve coverage of beef carcass surfaces equivalent to conventional spray application, thereby reducing water consumption demands for food safety systems.

Experimental approach

This research investigated the use of ESS and conventional spraying to apply both common and new chemical antimicrobials, as well as biological agents including a mixture of LAB, on chilled beef subprimals to replicate chilled carcasses and selected cuts for further aging and tenderizing. Prerigor, non-chilled beef from a federally inspected slaughter establishment was collected and inoculated with a cocktail of 8 STEC serotypes (O26:H11, O45:H2, O103:H2, O104:H4, O111:H-, O121:H19, O145:NM, and O157:H7) shortly after harvesting. The beef was then chilled simulating commercial procedures and treated with lactic acid (LA), lauric arginate ester (LAE), cetylpyridinium chloride (CPC), peracetic acid (PAA) and chlorine dioxide (ClO2). Outside rounds were then hung simulating the way a carcass side is hung, and strip loins were subjected to aging for 14 or 28 days at 4° C. Strips were used for testing the biological intervention (LAB). All treatments were applied with a small, portable commercial ESS to determine its potential application in small establishments.

Results

Reductions in STEC–8 obtained with LAE were 3.2 log10 and 2.2 CFU/cm2 when applied by conventional spraying or ESS, respectively. For LA, reductions were 3.2 and 1.7 log10 CFU/ cm2 by conventional spraying and ESS, respectively. The reductions obtained with ClO2 or PAA did not differ from those obtained by water, regardless of spray system or concentration, in the case of ClO2 (3 and 5 ppm). For LAB tests, both conventional and ESS spray delivered the LAB cocktail to a final concentration of 6.5±0.1 log10 CFU/cm² of beef. The population of STEC–8 was reduced by 0.4 log cycles for both spray methods and the surviving STEC–8 populations did not change after aging for 14 or 28 days.

Implications

The similar or smaller reduction obtained for LA and LAE using ESS in comparison to conventional spraying was reported by Diaz-Morse et al. (2013), although these authors found a slightly greater, but significant reduction, in counts of Salmonella Typhimurium when some antimicrobial compounds were applied with ESS. For other microorganisms these authors found no differences between spray systems. Among chemical interventions used, LA reduced more STEC–8 when applied via conventional spraying, whereas LAE resulted in greater reduction when applied with ESS. Antimicrobial intervention chemistry and intervention application technology should be carefully paired for optimum beef safety from STEC. In this study, the portable ESS showed little benefit. Inrelated studies, STEC CAP researchers at KSU are employing ESS to deliver antimicrobials to beef carcasses, whereas colleagues at the USDA-ARS in Wyndmoor, PA, are using a specially-designed cabinet to deliver antimicrobials to beef trim, subprimals, and steaks via ESS. These results will provide insight as to the benefits of commercial scale ESS cabinets. Biopreservatives such as LAB can be useful for reducing pathogens on food surfaces, though optimization of the numbers and activity of such interventions must be completed to assure maximal food safety preservation.

References:

Dias-Morse, P.N., Pohlman, F.W., Pinidiya, S.D., and C.L. Coffman. 2013. Microbial characteristics of ground beef processed from beef trimmings decontaminated by peroxyacetic acid alone or followed by organic acids interventions. Available at: http://dora.uark.edu/fedora/ repository/uark%3A3848/ OBJ/ResearchSeriesAgri612. pdf#page=11. Accessed 10 July 2015. Phebus, R.C., Sevart, N.J., Baumann, N.W., Phebus, R.K. 2014. Electrostatic spray cabinet evaluation to verify uniform delivery of chemical and biological solutions to pre-chilled meat animal carcasses. Available at: http://krex.k-state.edu/dspace/handle/2097/17824. Accessed 10 July 2015.


STEC CAP News Award Winners UC Davis Poster Winner Betty Feng, STEC CAP grad student of Dr. Christine Bruhn, won first place in the research poster competition at the Food Systems and Public Health Symposium in Sacramento, CA, on July 23, 2015. Her poster title was ‘Comparison Between Positive Deviance and Conventional Reading Approaches to Food Safety Education’. Congratulations Betty.

KSU Student Scholarship Winner Amanda Wilder, a STEC CAP funded graduate student at KSU, was the recipient of several prestigious awards recently. She received the Timothy R. Donoghue Scholarship from KSU and the Helen A. Snyder Kappa Delta Graduate Scholarship from the University of Idaho for outstanding academic performance, research contributions, and/or service to community organizations. Amanda was also the recipient of a Meat Industry Suppliers Alliance Scholarship from the Food Processing Suppliers Association as one of only a handful of students recognized for academic excellence and their intention of pursuing a career in the meat industry. Amanda is presently working on her M.Sc. degree under the direction of Dr. Randy Phebus. Congratulations Amanda.

Susan Ann Smith Mills Award Winner Zachary Stromberg was awarded the UNL Susan Ann Smith Mills Memorial Award on July 8th, 2015. Zachary is a graduate student of Dr. Rodney Moxley. The award recognizes outstanding graduate students conducting research in the biomedical science area and is based on their accomplishments and research credentials. Welcome Zack.

IAFP Honorary Life Membership Award Dr. Christine Bruhn, CE Specialist Emerita, Food Science and Technology, has been selected to receive Honorary Life Membership in the International Association for Food Protection (IAFP). Congratulations Christine, well earned/deserved.


STEC CAP News ...Directors Update ...continued from page 1 for capturing all of our Points on the Board (POB). I want to encourage everyone to keep the momentum going and continue to contribute all of your POB in a timely manner. This information is critical for preparing various reports and for communicating our accomplishments to our stakeholders and the public in general. Regarding the filing of reports, Dr. Moxley will be communicating more specific information to you in the coming weeks regarding the preparation of annual reports for 2015 and for drafting a statement of work and associated budget justifications for the upcoming year 5 of our STEC CAP. Additional information will also be forthcoming from Rod about preparing and requesting a no-cost extension to allow us to continue and complete the research we have been charged to tackle despite being delayed (through no fault of our own) from receiving the monies in a timely manner and initiating the research. Lastly, just a reminder to include the following verbiage for all projects or initiatives supported by the National Institute of Food and Agriculture (NIFA): “This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2012-68003-30155”. Next, I want to make you aware of two very important meetings that are just around the corner, the Annual Meeting of the International Association for Food Protection (IAFP; July 25-28th in Portland, OR) and the 9th Triennial International Symposium on Shiga Toxin (Verocytotoxin)-producing Escherichia coli (VTEC; September 13-16 in Boston, MA). We will be extremely well represented at both of these meetings, with many of our faculty and students serving as invited speakers and/or defending numerous posters detailing our research. Rod is also a coorganizer of a Pre-Congress Symposium at VTEC 2015 with Dr. Peter Feng (FDA) entitled “Food safety from farm and field to plate” and our very own Nick Sevart, a Ph.D. candidate from K-State, has been invited to showcase our veal initiative at this congress. Rod will also serve as chair and facilitator of the “Animal Reservoirs, Food, Environmental Contamination and Transmission” session during the main congress. You should

also know that just prior to IAFP in Portland, OR, Rod will be giving an overview of our STEC CAP program and progress on July the 24th at a specially-organized conference for all current research being funded via USDA-NIFA. While at IAFP, everyone is invited to convene for a working STEC CAP breakfast from 7:00 to 8:15 AM on Monday the 27th in room A105 at the Convention Center. Both Rod and Jeanette will address the team, and then Peter Taormina and our SAB members will comment on our progress thus far and make suggestions for what we should be doing for the road ahead. The meeting will conclude with brief presentations by 3 of our students. Looking forward to seeing you all in Portland and/or Boston. Although we have much to be proud of and much to be thankful for, we still have plenty of objectives to address and quite a few more milestones to meet. That being said, one of the things that was abundantly obvious to me as I listened to several of the presentations at our most recent annual meeting was the scope and magnitude of our cooperative research efforts. Most of the projects that were highlighted were truly collaborative in nature and would not have been possible unless we were selected to play on the same team for this grand experiment called a “Cooperative Agricultural Project”. In short, we are collectively conducting state-of-the-art, targeted, and holistic research to address a significant problem that could not be addressed to the same depth or in a timely manner without the selfless efforts, time, and talents of our entire team. In a sense we are an experiment within an experiment and we are confirming that with the right people, infrastructure, support, and resources the CAP concept works…the sum is most assuredly greater than the parts and the return on investment is palpable. We are entering the home stretch folks, let’s stay focused, sprint towards the tape, and finish strong as a team. Kudos to everyone. Ever onward. – John Luchansky


STEC CAP News Luchansky receives Souderton Area High School (SAHS) Friend of Education Award Dr. John B. Luchansky was the recipient of a Souderton Area High School (SAHS) Friend of Education Award. This annual award recognizes the outstanding contributions by a member of the community to enhance and encourage leadership, citizenship, and character development of students in the Souderton Area School District. The award is presented annually to a community leader who has invested their time and resources in the students’ education. Along with Drs. Anna Porto-Fett, Brad Shoyer, and Laura Shane of the USDA-ARS-ERRC in Wyndmoor, PA, and as part of the STEC CAP internship and externship programs, John partnered with administrators, faculty, staff, and students at SAHS to provide exploratory and informational trips to the ERRC to expose students to a scientific research center and to arrange for summer internships for students and training workshops for faculty and staff. The team from ERRC also made several

presentations on food science/safety with an emphasis on STEC at both SAHS and at ERRC and helped organize and host a workshop for SAHS faculty under the leadership of Dr. Dann Hussmann and Katie McKee. The award was presented to Dr.

Luchansky by Principal Sam Varano, Assistant Principal Kyle Longacre, and Superintendent Frank Gallagher at Souderton Area High School on May 26, 2015.

...My STEC CAP Experience ...continued from page 1 students from six university and research centers across the U.S. As these researchers were my secret shoppers, my research simply could not have been done without their involvement. These collaborations also provided me with the opportunity to visit numerous campuses, give seminars, and build relationships with fellow graduate students and faculty. I felt comfortable turning to researchers

with my questions throughout my research design and data analysis. Although I completed my Ph.D. in May, my relationship with STEC collaborators did not end there. In February of 2015, I began a position as a Research Assistant Professor at the Center of Excellence for Food Safety Research in Child Nutrition Programs at Kansas State University.

Here, I continue to work with researchers that I initially met through the grant in addition to maintaining other STEC CAP relationships. I encourage the graduate students on the STEC CAP grant to engage with other collaborators as much as possible- you will gain a large amount of valuable knowledge. – Ellen Thomas


STEC CAP News

Check us out on the Web! Visit us at: www.stecbeefsafety.org Subscribe to the listserv. Send an email to: listserv@unl.edu In the message field: subscribe stecbeefsafety

This project was supported by Agriculture and Food Research Initiative Grant No. 2012-68003-30155 from the USDA National Institute of Food and Agriculture, Prevention, Detection and Control of Shiga Toxin Producing Escherichia coli (STEC) from Pre-Harvest Through Consumption of Beef Products Program –A4101.

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