THE EFFECTS OF CURRENT AGRICULTURAL PRACTICES ON THE SURVIVAL AND TRANSFER OF SHIGA TOXIN PRODUCING ESCHERICHIA COLI AND SALMONELLA ON SMALL MULTI-FUNCTIONAL FARMS IN ALABAMA

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: NEW
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0231458
• Project No.: ALA013-1-12015
• Project Start Date: Oct 1, 2012
• Project End Date: Sep 30, 2017

Project Director
Wang, L.

Recipient Organization
AUBURN UNIVERSITY
108 M. WHITE SMITH HALL
AUBURN,AL 36849

Performing Department
Animal Sciences

Non Technical Summary
Alabama has unique weather conditions compared to the other parts of the United States. It has very hot summers and mild winters with copious precipitation throughout the year. Alabama receives an average of 56 inches (1,400 mm) of rainfall annually and enjoys a lengthy growing season of up to 300 days in the southern part of the state. The average annual temperature is 64 F. In the state of Alabama, there are significant amount of small farms. Those farmers have fewer cattle compared to huge commercial ranches and they grow vegetables and fruits on the farms to meet the community needs and make profit. In this research program, studies will be planned to provide additional information to our current knowledge on "the effects of feed, management, and stresses on GI tract microflora and shedding of pathogenic bacteria", "influence of weather conditions on the survival and transfer of pathogens on farm" and "molecular survival mechanisms of STEC and Salmonella". The outcomes are expected to fill some of the gaps regarding the pre-harvest food safety control. Most importantly, this research program will be dedicated to help the small farmers in the state of Alabama to establish efficient and feasible intervention methods to enhance their product safety. Due to the happening of several multi-state foodborne outbreaks, consumers are now paying more attention to local foods and they want to be able to put a face onto their products. By having more efficient intervention and management strategies in place, both the farmers and consumers will be more confidence about their food, and ultimately, the farmers can make more profit for living.

Animal Health Component

20%

Research Effort Categories

Basic

20%

Applied

80%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
712	1430	1100	10%
712	3310	1100	15%
712	3320	1100	15%
712	3330	1100	15%
712	3399	1100	15%
712	3440	1100	15%
712	4099	1100	15%

Knowledge Area
712 - Protect Food from Contamination by Pathogenic Microorganisms, Parasites, and Naturally Occurring Toxins;

Subject Of Investigation
4099 - Microorganisms, general/other; 1430 - Greens and leafy vegetables; 3320 - Meat, beef cattle; 3440 - Meat, dairy cattle; 3310 - Beef cattle, live animal; 3330 - Other beef cattle products; 3399 - Beef cattle, general/other;

Field Of Science
1100 - Bacteriology;

Keywords

shiga toxin

escherichia coli

salmonella

cattle

calf

fresh produce

gi tract microflora

Goals / Objectives
The proposed research program is designed to better understand the survival and transfer of Shiga-toxin producing Escherichia coli (STEC) and Salmonella spp. on small farms in the State of Alabama. The objectives of this research program are to develop studies and generate research results that can contribute to the better understanding of 1. The effects of feed changes/management practices/transportation stresses on the GI tract microbial diversity and the shedding of STEC and Salmonella, 2. The influence of weather conditions on transfer, survival, growth and recovery of foodborne pathogens on farms, 3. The molecular survival mechanism of STEC and Salmonella and their dynamic pathogenicity

Project Methods
1. The effects of feed changes/management practices/transportation stresses on the GI tract microbial diversity and the shedding of STEC and Salmonella. A total of 120 calves born around November 2011 will be brought to the E.V. Smith center in Spring 2012. Half of the group will be fed with wet diet while the other half will be fed with dry diet. These calves will stay on the controlled diet for 45 days before they are taken for a 21-h road trip. For the microbial part, fecal, hide and environmental samples at different time points will be collected. The time points are divided into two groups, "diet treatments" and "road-trip stresses". The baseline will be built based on samples collected when calves get their first vaccination (May 2012). After the initial sampling, fecal, hide and environmental samples will be collected in the middle of the 45-day diet treatment and at the end of 45-day diet treatment. Total microbial profile as well as the present of STEC and Salmonella will be studied. Environmental samples collected from the farm will include water, feed and bedding materials and the purpose is to find the potential of cross-contamination routes. 2. The influence of weather conditions on transfer, survival, growth and recovery of foodborne pathogens on farms. In this study, uidA-based PCR and DGGE will first be used to group the E. coli fingerprints from sheep, cattle and rabbit fecal samples, soil samples and the pond (including water runoffs)collected from small farms. The uidA gene is chosen because this gene encodes the 1-glucuronidase enzyme and is detected in 97.7% of 435 E. coli isolates from treated and raw water sources by DNA-DNA hybridization. Once the fresh produce gets transplanted to the field, the total E. coli diversity on produce leaves will be monitored. The goal is to understand the transfer of E. coli communities before and after weather changes. Both the real-time PCR and traditional plating methods will be used to evaluate the quantity changes of the total E. coli communities. 3. The molecular survival mechanism of STEC and Salmonella and their dynamic pathogenicity. Research program will be developed to investigating the function of E. coli O157:H7 extracellular structures and comparing the different roles of these extracellular structures between E. coli and Salmonella. Extracellular structures are chosen because they are the first barriers that protect cells from environmental stresses. Microarrays and real-time PCR will be used to monitor the expression of extracellular structural genes under various stresses as well as the expression of pathogenic genes. In vitro studies will be conducted via the collaboration with Veterinary school on campus to examine the effects of formed hyper-virulent strains.

Progress 10/01/16 to 09/30/17

Outputs
Target Audience:My target audience include scientists, students, government agencies, as well as stakeholders (such as our farmers and cattle owners). Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This 5-year HATCH grant allowed me to train graduate students in the lab, undergraduate students both in the lab and in the classrooms. I have graduated 7 graduate students (1 Ph.D., 5 M.S. and 2 M. Ag.). I also trained two postdoc researchers. I have served on the committee of an additional of 27 graduate students. How have the results been disseminated to communities of interest?The research results have been disseminated to communities of interest through my participantion at scientific meetings as well as the workshops/state meetings: Scientific meetings: Zhao, T. , Wang, L., Zhao, P., Yuan, J., Richburg, G., and Doyle, M. 2016. A wash treatment of "Fit-L" on cattle for reduction of foodborne pathogens and its safety on eye evaluation. International Association for Food Protection annual meeting. St. Louis, MO. July 31-August 3, 2016. Han, D. †, Hung, Y., and Wang, L. 2016. Impact of near-neutral electrolyzed oxidizing water on Vibrio spp. in Eastern oyster (Crassostrea virginica). International Association for Food Protection annual meeting. St. Louis, MO. July 31-August 3, 2016. Davenport, C. G., Wang, L., and Bratcher, C. L. 2016. Peracetic acid effects on shelf life and survival of E. coli on beef steaks. American Society of Animal Science Southern Section annual meeting, San Antonio, TX. February 6-9, 2016. Zhao, T. Wang, L., Zhao, P., Chen, D., Doyle, M. 2015. Reduction of shiga toxin producing E. coli and Salmonella Typhimurium on cattle hides by spray treatment with Levulinic acid plus sodium dodecyl sulfate. International Association for Food Protection annual meeting. Portland, OR. July 24-28, 2015. Corkran, S., Brar, J., Bailey, M., Oliver, H., Waddell, J., Wang, L., Bratcher, C., and Singh, M. 2015. Prevalence of Escherichia coli in small and very small beef slaughter plants. International Association for Food Protection annual meeting. Portland, OR. July 24-28, 2015. Yuan, J., Reutebuch, E., and Wang, L. 2015. Comparison of different enumeration protocols for indicator microorganisms in water and sediment. International Association for Food Protection annual meeting. Portland, OR. July 24-28, 2015. Liao, C., Zhao, Y., and Wang, L. 2015. Development of real-time RT-PCR based molecular survival models of Vibrio parahaemolyticus in post-harvest oysters during chilled storage. American Society for Microbiology 2015 annual meeting. May 30-June 2, New Orleans, LA. Yuan, J., Wang, L., and Reutebuch, E. 2014. Water quality indicator microorganism enumeration from sediments and surface water by using 3M Petrifilm™ and Coliscan Easygel. 28th Alabama Water Resource Conference. September 3-5. Orange Beach, AL. DeGeer, S., Wang, L., Singh, M., Bilgili, S., and Bratcher, C. 2014. Evaluation of multiple temperatures of lactic acid and sodium metasilicate on microbial parameters of fresh beef. International Association for Food Protection annual meeting, Indianapolis, IN, August 3-6, 2014. Zhao, L., Jin, T., Yuan, J. , and Wang, L. 2014. Evaluation of the effects of a newly designed antimicrobial solution on Listeria monocytogenes and ready-to-eat meat shelf life quality. International Association for Food Protection annual meeting, Indianapolis, IN, August 3-6, 2014. Palmer, C., Bratcher, C., Singh, M., and Wang, L. 2014. Survival of E. coli O26 with different pathogenic gene profiles in food and environmental samples. Institute of Food Technologists annual meeting, New Orleans, LA, June 21-24, 2014. Broady, J. W. , Gasser, G., Westbrook, B., McCray, M., Wang, L., and Schwartz, E. 2014. Growth of Listeria monocytogenes as a biofilm: kinetics, chemical composition, and virulence properties. Research week, Auburn University, April 15, 2014. Broady, J. W. , Wang, L., Moss, A. G., Brandebourg, T. D., and Schwartz, E. M. 2014. Microbiota diversity is inversely related to adiposity in Mangalica pigs. American Society of Animal Science, Joint Annual Meeting, Kansas City, MO, July 20-24, 2014. Fisher, K., Jin, Z. T., Bratcher, C. L., and Wang, L. 2014. An initial evaluation of a novel antimicrobial solution on fresh meats. American Meat Science Association 67th Reciprocal Meat Conference, Madison, WI, June 15-18, 2014. (see B.2.b) Degeer, S.†, Wang, L., Singh, M., Bilgili, S., and Bratcher, C. L. 2014. Evaluation of lactic acid and sodium metasilicate against pathogens of concern on fresh beef, pork, and deli meats. American Meat Science Association 67th Reciprocal Meat Conference, Madison, WI, June 15-18, 2014. Broady, J., Liles, M., Bratcher, C., Schwartz, E., and Wang, L. 2014. Microbial diversity of deli roast beef and survival of Listeria monocytogenes. American Society of Animal Science Southern Section annual meeting, Dallas, TX, February 2-4, 2014. Palmer, C., Bratcher, C., Singh, M., and Wang, L. 2014. Survival comparison of shiga toxin producing Escherichia coli (STEC) O26 and farm isolated O26 in ground beef and the environment. American Society of Animal Science Southern Section annual meeting, Dallas, TX, February 2-4, 2014. Smith, J. , Wang, L., Bratcher, C., Bilgili, S., and Singh, M. 2013. Evaluation of inoculation and carcass rinse methods on the recovery of Salmonella Enteritidis and Campylobacter jejuni from broiler carcass. International Association for Food Protection annual meeting, Charlotte, NC, July 28-30, 2013. Wideman, N. , Bilgili, S., Thippareddi, H., Wang, L., Bratcher, C., and Singh, M. 2013. Evaluating post-evisceration processing steps and in-plant antimicrobial treatments against Campylobacter, E. coli and aerobic bacteria on poultry carcass. International Association for Food Protection annual meeting, Charlotte, NC, July 28-30, 2013. Broady, J. , Liles, M., Bratcher, C. L., Schwartz, E., and Wang, L. 2013. Survival and growth of Listeria monocytogenes on deli roast beef during refrigeration storage. American Meat Science Association 66th Reciprocal Meat Conference, Auburn, AL, June 16-19, 2013. Palmer, C. , Bratcher, C. L., Singh, M., and Wang, L. 2013. Survival comparison of shiga toxin producing Escherichia coli (STEC) O26 and farm isolated O26 in ground beef. American Meat Science Association 66th Reciprocal Meat Conference, Auburn, AL, June 16-19, 2013. Palmer, C. , Bratcher, C. L., Singh, M., and Wang, L. 2013. Prevalence of non-O157 shiga toxin producing Escherichia coli shed by beef calves before and after weaning. International Association for Food Protection annual meeting, Charlotte, NC, July 28-30, 2013. Zhao, L. , Tyler, P. J., Rankins, D., McCaskey, T. A., and Wang, L. 2013. The effect of weaning stress on the levels of shiga toxin producing Escherichia coli and fecal butyrate-producing bacteria in young calves. International Association for Food Protection annual meeting, Charlotte, NC, July 28-30, 2013. Zhao, L. , Tyler, P. J., McCaskey, T. A., Rankins, D., and Wang, L. 2013. Dietary effects on Escherichia coli O157:H7 shedding in beef cattle during transport. International Association for Food Protection annual meeting, Charlotte, NC, July 28-30, 2013. Extension talks: Wang, L. 2016. Survival and transmission of zoonotic pathogens in agricultural environments. Beef Cattle Conference, August 13th, 2016. Wang, L. 2015. Evaluation of a novel antimicrobial solution as a marination supplement. Beef Cattle Conference, August 6th, 2015. Wang, L. 2015. Applied microbiology and food safety. China Ocean University. June 2nd, 2015 Wang, L. 2014. Zoonotic diseases & the environment. Cluster hire, Environmental health section, November 12th, 2014. Wang, L. 2013. Rapid Detection Methods for Poultry-borne Pathogens. Poultry Science Association annual meeting, San Diego, CA, July 25th, 2013. Wang, L. 2012. Detection and Identification of Zoonotic Pathogens, Material Engineering Seminar, Samuel Ginn College of Engineering, Auburn University, Auburn, AL, September 24th, 2012 What do you plan to do during the next reporting period to accomplish the goals?This is the end of my 5-year HATCH. The next report period will be under a new HATCH title.

Impacts
What was accomplished under these goals? Under these goals, we were able to identifythat the weaning procedures and the weaning diets, together with transportation can impact the shedding level of pathogenic E. coli in calves. We also identified that E. coli O26 (Shiga toxin producing E. coli) is the main STEC serotype found in the State of Alabama. By using the model strains, we found that the pathogenic genes did impact the survival of E. coli O26 in different enviornmental samples. E. coli O26 strains were able survive in different environmental samples, such as soil, bedding materials, water, fecal samples for up to three months. This finding indicates that controlling the shedding level and shedding pravelence of pathogenic E. coli in calves is very important. This is of great importance not only for animal product safety but also for fresh produce safety, since fecal materials can be used as fertilizers or soil ammendment for fresh produce. Wealso established prodictive models to predict the survival of pathogens in the meat anddeveloped with other scientists novel intervention strategies to reduce pathogen levelson meat products (pork skins, pork chops and ready-to-eat meat products).

Publications

• Type: Journal Articles Status: Published Year Published: 2017 Citation: Liao, C., Zhao, Y., and Wang, L. 2017. Establishment and validation of RNA-based predictive models for understanding survival of Vibrio parahaemolyticus in oysters stored at low temperatures. Applied and Environmental Microbiology. 83(6), e02765-16.
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Zeng, Q., Tian, X., and Wang, L. 2017. Genetic adaption of microbial populations present in high-intensity catfish production systems with therapeutic oxytetracycline treatment. Scientific Reports. Published online on December 13 2017.
• Type: Journal Articles Status: Accepted Year Published: 2018 Citation: Han, D., Hung, Y., and Wang, L. 2017. Evaluation of the antimicrobial efficacy of neutral electrolyzed water on pork products and the formation of viable but nonculturable (VBNC) pathogens. Food Microbiology. Accepted.
• Type: Journal Articles Status: Accepted Year Published: 2018 Citation: Wang, Y., Huang, C., Wang, L., Welles, E., and Chiba, L. 2017. Effect of diet complexity, multi-enzyme complexes, essential oils, and benzoic acid on weanling pigs. Livestock Science. Accepted.

Progress 10/01/15 to 09/30/16

Outputs
Target Audience:This year, one of the major research we carried out is to evaluate the water quality on farm. The surface water here include in-coming and out-going streams and ponds. We sampled four different farms in Alabama. These farms are different in size (range from 500 cattle to about 25 cattle). These farms have different animal species on it and all of these animals have access to the surface water souces we sampled. The reason we want to sample the water is because based on the new FSMA produce safety rule, water used for irrgation needs to be minitored and a microbial profile of the water needs to be built. While the FDA requires the monitoring to follow the current EPA protocols, differences were observed already when different sampling protocols were used, different sampling times were chosen, or different enumeration protocols were chosen. In addition, we also want to find if the animal agriculture really generate impact on water quality. Our target audiences are farmers, produce growers, general consumers, and government agencies. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The results generated can directly help the government agencies to understand the problems associated with water sampling. There is an urgent need for the government agencies to issue additional documents to help farms and inspectors to understand how to sample the water, when to sample the water, and how to enumerate the indicator microorgansims? How have the results been disseminated to communities of interest?A presentation has been given at the Alabama Beef Cattle Conference on August 13 2016. In addition, when NIFA program director visited Auburn University, the PI also communicated the results with them. What do you plan to do during the next reporting period to accomplish the goals?The data generated will be published on scientific journals so more people can know about these results. For goal 3, "The molecular survival mechanism of STEC and Salmonella and their dynamic pathogenicity". A project will be carried out in the next year to find out the impact of near neutral electrolyzed water on STEC and Salmonella. Surface enhanced raman spectroscopy and transcriptomic techniques will be used to understand the survival mechanisms.

Impacts
What was accomplished under these goals? The outcome of this years results helps us to better understand the influence of weather conditions on water quality (water contamination) on farm (goal 2).

Publications

• Type: Theses/Dissertations Status: Submitted Year Published: 2016 Citation: Detection and monitoring of microbes of concern in animal production environment
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Wideman, N., Bailey, M., Bilgili, S., Thippareddi, H., Wang, L., Bratcher, C. L., Sanchez-Plata, M., and Singh, M. 2016. Evaluating of the best practices for Campylobacter and Salmonella reduction in poultry processing plants. Poultry Science. 95(2): 306-315.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Zhao, T., Wang, L., Zhao, P., Yuan, J., Richburg, G., and Doyle, M. P. 2016. Reduction of Shiga toxin-producing E. coli and Salmonella Typhimurium on cattle hides by spray treatment with Fit-L (Levulinic acid plus sodium dodecyl sulfate). MOJ Food Processing & Technology. 2(5): 00049.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Broady, J. W., Han, D., Yuan, J., Liao, C., Bratcher, C. L., Lilies, M. R., Schwartz, E. H., and Wang, L. 2016. Survival and metabolic activity of Listeria monocytogenes on Ready-to-eat roast beef stored at 4 �C. Journal of Food Science. 81(7): M1766-1772.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: DeGeer, S. L., Wang, L., Hill, G. N., Singh, M., Bilgili, S. F., and Bratcher, C. L. 2016. Optimizing application parameters for lactic acid and sodium metasillicate against pathogens on fresh beef, pork, and deli meats. Meat Science. 118: 28-33.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Fisher, K. D., Bratcher, C. L., Bilgili, S. F., Owsley, W. F., Jin, T., and Wang, L. 2016. Evaluation of a novel antimicrobial solution and its potential for control E. coli O157:H7, non-O157 shiga toxin-producing E. coli, Salmonella spp., and Listeria monocytogenes on beef. Food Control. 64: 196-201.

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Stresses such as weaning and transport may contribute to higher fecal shedding of pathogenic E. coli. Understanding and identifying pre-harvest controls to reduce E. coli shedding is important for food safety. The objective of this study was to evaluate the effects of two diets [dry feed (DF) and high moisture (HM)] used during the preconditioning period together with hay treatments applied before transportation on the shedding of Shiga toxin producing E. coli. One hundred and eighteen calves were randomly assigned to two weaning diets. Forty-nine days after being on two diets, half of the calves were randomly selected and transported on a truck for 24 hours ("transported"), while the "non-transported" calves stayed in pens. Before transport, half of the "transported" and half of the "non-transported" calves were given a mixed-grass hay for 48 hours (Hay) while the rest of the calves did not receive hay (No Hay). Fecal samples were collected before (BT), 24 hours after (RAT) and 15 days after transport (AT15). The "non-transported" calves were sampled at BT and AT15. The prevalence of E. coli O157 and Shiga toxin producing genes were determined using PCR. Regardless of hay treatment, DF-fed calves had increased E. coli O157 shedding prevalence right after transportation while HM-fed calves had increases 15 days after transportation. No significant difference was seen for Shiga toxin producing gene prevalence (P > 0.05). In addition to Escherichia coli O157:H7, six non-O157 shiga toxin-producing Escherichia coli (STEC) serogroups were added to the zero-tolerance adulterant list in 2012. Among them, STEC O26 has been one that was involved in several recalls and outbreaks and has also been the dominant serovar found in the HATCH project. The presence of three major pathogenic genes (stx1, stx2, and eaeA) was checked by using multiplex PCR. Two major pathogenic gene profiles were seen: three of the farm isolates contain only the eaeA gene; one farm isolate and one clinical isolate have both the eaeA and the stx1 genes. To find out if different O26 virulence profiles could influence their survival in ground beef and environmental samples, different O26 cocktails were inoculated into samples of ground beef, bovine feces, bedding materials, and water samples. One cocktail was made of isolates containing only the eaeA gene and another cocktail was made of farm and clinical isolates containing both the eaeA and stx1 genes. Inoculated beef samples were stored at 4°C for 10 days and the inoculated environmental samples were stored at ambient temperature for up to 30 days. Results showed that virulence gene profiles do not have an impact on STEC O26's ability to survive in ground beef and in environment (P > 0.05). The inoculation levels, sample types as well as the storage times are the major factors that impact O26 survival (P < 0.05). Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?We had one postdoc and one M.S. student trained with this HATCH proposal. How have the results been disseminated to communities of interest?Results have been disseminated to the public by publishing papers on scientific journals. Palmer, C., Bratcher, C. L., Singh, M., and Wang, L. 2015. Characterization and survival of environmental Escherichia coli O26 isolates in ground beef and environmental samples. Journal of Food Science. 80(4): M782-787. Zhao, L., Tyler, P. J., Starnes, J., Rankins, D., McCaskey, T. A., and Wang, L. 2014. Evaluation of weaning stress on Escherichia coli O157 shedding, body weight and fecal bacterial communities in beef calves. Foodborne Pathogens and Disease. 11(1): 55-60. Zhao, L., Tyler, P. J., Starnes, J., Bratcher, C. L., Rankins, D., McCaskey, T. A., and Wang, L. 2013. Correlation analysis of shiga toxin producing Escherichia coli shedding and fecal bacterial composition in beef cattle. Journal of Applied Microbiology. 115(2): 591-603. What do you plan to do during the next reporting period to accomplish the goals?This is the final report of this HATCH grant.

Impacts
What was accomplished under these goals? We have succesfully accomplished the three objectives listed in the HATCH proposal. We have evaluated the impact of weaning diets on the shedding of pathogenic E. coli and also their impact on transportation management. We also investigated the impact of pathogenic genes on the survival of STEC O26 in both meat and enviormental samples.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: Characterization and survival of environmental Escherichia coli O26 isolates in ground beef and environmental samples. Journal of Food Science. 80(4): M782-787.

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: farmers and producers Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Two M.S. students graduated. How have the results been disseminated to communities of interest? Journal publications and presentations. What do you plan to do during the next reporting period to accomplish the goals? To better understand the survival of microorganisms in water as irrigation water/pond water is now considered as another source of contamination.

Impacts
What was accomplished under these goals? In 2014, a better understanding of the"survival of E. coli O26 in environmental samples and meats" was achieved and the summarized results (manuscript) got accepted by Journal of Food Science.

Publications

• Type: Journal Articles Status: Published Year Published: 2014 Citation: " Guo, M.*, Jin, T. Z., Wang, L.�, Scullen, C. J., and Sommers, C. H. Antimicrobial films and coatings for inactivation of Listeria innocua and Salmonella Typhimurium on Ready-to-eat meat. 2014. Food Control. 40: 64-70. Impact Factor: 2.738; 5-year Impact Factor: 3.006 " Guo, M.*, Jin, T. Z., Geveke, D., Fan, X., Site, J., and Wang, L.� 2014. Evaluation of microbial stability, bioactive compounds, physicochemical properties, and consumer acceptance of pomegranate juice processed in a commercial scale pulse electric field system. Food and Bioprocess Technologies. 7: 2112-2120. Impact Factor: 4.115 " Zhao, L.*, Tyler, P. J., Starnes, J., Rankins, D., McCaskey, T. A., and Wang, L.� 2014. Evaluation of weaning stress on Escherichia coli O157 shedding, body weight and fecal bacterial communities in beef calves. Foodborne Pathogens and Disease. 11(1): 55-60.

Progress 10/01/12 to 09/30/13

Outputs
Target Audience: The target audiences are farmers and cow/cattle operation managers in the state of Alabama as well as scientists who are interested in pre-harvest control of foodborne pathogens. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Significant progress has been made on several parallel studies. Through the cattle trial conducted in E. V. Smith, weaning has been approved to be an important step that not only play a role in GI tract microflora system establishment but also impact the STEC shedding levels and prevalence. The diet used during the weaning and pre-conditioning field can directly influence the GI tract microflora as well as shedding. Higher STEC shedding levels and prevalence associated with younger cattle age, lower fecal bacterial diversity and lower butyrate-producing bacteria levels. A significant decrease of body weight was observed during weaning, regardless of diet. Calves fed the HM diet lost more weight than the DF-fed calves during weaning. Both the CHROMagarTM and PCR results showed that the overall prevalence of O157 increased significantly during weaning and stayed at the higher level during the pre-conditioning period. The increase of O157 prevalence was observed in HM-fed calves during weaning but not in DF-fed ones. Transportation significantly increased the O157 shedding levels of the DF calves, but did not change the O157 shedding level of HM calves. With the hay supplement, the HM calves had an increase in O157 shedding levels during transportation, while the O157 shedding levels did not change for the DF- calves. For HM-calves, transportation did not change the O157:H7 prevalence. For objective 2 studies, a ground beef survival tests comparing the clinical and farm strains showed a similar survival rate with different STEC O26 strains. The environmental tests using the same strains showed slight significant differences within each trial, but overall there was no difference. These results indicate that the presence of the pathogenic genes does not influence survival in ground beef or in the environment. How have the results been disseminated to communities of interest? Publications (abstracts and journalpubkcations)are generated from studies. What do you plan to do during the next reporting period to accomplish the goals? The next step for current study is to better understand the transportation stress and the effects of different diets on STEC shedding during transportation.

Impacts
What was accomplished under these goals? Thisresearch program aims to better understand the survival and transfer of shiga toxin producing Escherichia coli (STEC) and Salmonella spp. on small multi-functional farms in Alabama. To be specific, there are three objectives: 1, understand the feed changes/management practices/transportation stresses on the GI tract microbial diversity and the shedding of STEC and Salmonella; 2, investigate the influence of weather conditions on transfer, survival, growth and recovery of foodborne pathogens on farm; 3, find out the molecular survival mechanisms of STEC and Salmonella and their dynamic pathogenicity. To achieve objective 1, a cattle trial was conducted at the E. V. Smith Research Center. In this study, 120 dams and 120 calves were used in this trial. The study started from January 2012 and ended on December 2012. Two different types of feed were used for calf weaning, dry feed (DF) and high moisture (HM) feed. The calves were sampled (direct fecal grab samples were obtained) before they were weaned and were sampled multiple times during the 48-day weaning and pre-conditioning period. Those fecal samples were plated onto selective agar and the presence/absence as well as the concentration of STEC was calculated. Once the calves were weaned and pre-conditioned, they were put on a truck for 24 h to mimic transportation stresses and were sampled again after they returned back to E.V. Smith Center. All fecal samples were analyzed in the year of 2013 and promising results were seen from not only the plate count results but also the molecular fingerprinting result of GI tract total microflora. To achieve objective 2, environmental samples were collected from different cow/calf operations in the state of Alabama. Those samples included feed, water, as well as bedding materials. Genetically modified STEC O26 were artificially inoculated into those samples and the inoculated samples were held at room temperature for up to 30 days. The survival of STEC were monitoring every 5 days during the 30-day trial. Experiments were done twice in the year of 2013. Currently, the PI is working on the research plan for objective 3. All the data generated from studies of objective 1 & 2 had been summarized and submitted to regional and national meetings as well as peer reviewed scientific journals.

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: 0