Pre- and Post-Harvest Control of Foodborne Pathogens in Poultry Processing Environment and Poultry Products

<p>NON-TECHNICAL SUMMARY:<br/> Foodborne illnesses are a regular feature and concern for food safety and public health in the United States. It is estimated that every year foodborne diseases cause 9.4 million illnesses, in the United States, of those about 1 million and 0.8 million illnesses are caused by Salmonella and Campylobacter, respectively (Scallan et al., 2011). Consumption of undercooked poultry products contaminated with Salmonella and Campylobacter have been implicated in foodborne illnesses (Altekruse et al., 1999; CDC 2010a). Poultry is considered an important reservoir of pathogenic bacteria like Salmonella and Campylobacter jejuni and Listeria monocytogenes. Live birds harbor these pathogenic bacteria in their intestines, feathers and skin which lead to contamination of carcasses during slaughtering and processing (Corry, 2007). Keeping in view the public
health significance of Salmonella and Campylobacter and frequent contamination of poultry carcasses with these pathogens, USDA's Food Safety and Inspection Service (FSIS) has recently introduced new performance standards for poultry processing plants to reduce Salmonella and Campylobacter contamination in poultry carcasses (USDA FSIS 2010). Listeria monocytogenes is another pathogen of concern to public health. It is estimated to cause approximately 2,500 illnesses, 2,300 hospitalizations, and 500 deaths each year in the United States (Mead et al., 1999). Listeria monocytogenes has been isolated from raw meat and poultry but it is a major concern in ready-to-eat (RTE) meat and poultry products. Because of high case fatality rate and public health significance, USDA FSIS maintains a zero tolerance policy of L. monocytogenes in RTE meat and poultry products. Various outbreaks have been
linked to consumption of RTE meat and poultry products contaminated with L. monocytogenes (CDC, 2010b). As poultry and poultry products per capita consumption increase annually, the risk associated with foodborne illnesses from Salmonella, Campylobacter and L. monocytogenes contaminated poultry products will also increase. Many pre-and post-harvest interventions have been applied to restrict the occurrence of foodborne pathogens at grow out farms, processing plants and finished poultry products, but none has resulted in total elimination or removal of foodborne pathogens in poultry products. In order to improve the public health by ensuring food safety, there is great need to decrease the prevalence of these pathogens in poultry products. Therefore, there is critical need for additional interventions to use along with the existing preventive measures to further reduce the contamination
of poultry products with foodborne pathogens. The proposed research will be undertaken to reduce or eliminate different foodborne pathogens in raw, processed and finished or RTE poultry products that will be achieved by antimicrobial interventions by using USDA approved antimicrobials at the pre- and post-harvest steps of poultry processing.
<p>APPROACH:<br/> Objective 1: At the pre-harvest level various dietary modifications and management aspects (for example competitive exclusion, modifications in broiler feed and water, feed withdrawal) related to broiler production will be undertaken to assess their role in pre-harvest food safety. Different commercial bacteriophage products targeting Salmonella will be tested on poultry feathers and carcasses to reduce the level of Salmonella contamination. Bacteriophage dose and contact time to kill common poultry-borne Salmonella serotypes will be determined in vitro. Preliminary studies will be carried on live birds to determine the appropriate number of birds per treatment and number of replications for this study in order to have least variability in results/findings. Objective 2: For the control of foodborne pathogens like Salmonella and Campylobacter spp. during
poultry processing and at post-harvesting, novel USDA approved antimicrobials will be tested for their efficacy at different steps in poultry processing such as scalding, post-pick, chilling and pre-chill and post-chill carcass dips/sprays. Novel antimicrobials such as lauric arginate (LAE), will be tested for its efficacy against Salmonella and Campylobacter in ground chicken, ground turkey and chicken breast fillets. As an example, the approach to using LAE for control of Salmonella in poultry products: ground chicken procured locally will be inoculated with different Salmonella serotypes. The biocide effect of LAE against these Salmonella serotypes will also be determined in vitro. Inoculated ground chicken will be placed in sterile bags and treated with different concentrations of LAE. Each bag of treated ground chicken will be stored at 4C for 3 days. Duplicate samples per treatment
will be analyzed after 0, 1, 2 and 3 days for Salmonella and total psychrotrophic bacteria, pH and objective color. This study will be repeated three times and recovery of the surviving Salmonella populations will be made on selective media. Randomized block design will be used to determine differences between trials, among treatments and storage days, and treatment vs day interaction. Objective 3: Novel USDA approved antimicrobials like listeria-lytic bacteriophages and different lactic acid bacterial strains will be tested for their efficacy against L. monocytogenes under vacuum or modified atmosphere packaging in various RTE poultry products. Briefly, RTE poultry products such as turkey ham procured locally or produced in meat processing lab will be inoculated with cocktail mixture of L. monocytogenes strains and treated with viable LAB strains. Objective 4: Studies will also be
carried out to elucidate the mode of action of these antimicrobials for better understanding and application to control foodborne pathogens in poultry products. The methods used to assess the mechanism of action will depend on the type of antimicrobial selected. Various techniques such as transmission electron microscopy, and nucleic acid staining combined with fluorescent microscopy and flow cytometry will be utilized to elucidate the mode of action of antimicrobials.
<p>PROGRESS: 2012/01 TO 2012/12<br/>OUTPUTS: Currently, the poultry industry in the United States is faced with a problem of high prevalence of Salmonella in ground and comminuted poultry products such as ground chicken, ground turkey, and mechanically separated poultry. Recently ground turkey has been involved in a large multistate foodborne outbreak caused by Salmonella. Thus, it is critical to apply additional novel interventions to reduce the prevalence of Salmonella in ground poultry products. In the current study, the antimicrobial efficacy of lauric arginate (LAE), a USDA approved novel antimicrobial was tested against Salmonella survivability in ground chicken under refrigerated storage. The effect of LAE treatments on total aerobes, pH and objective color were also assessed in ground chicken. Ground chicken samples were inoculated with a Salmonella cocktail
consisting of four different serotypes (S. Enteritidis , S. Heidelberg, S. Kentucky and S. Typhimurium) and then treated with 200 and 400 ppm of LAE. The samples were stored at 4 C and analyzed on d 0, 1, 3, 5, and 7 for Salmonella, total aerobes, color and pH. PARTICIPANTS: Chander S. Sharma, Amanda Ates, P. Joseph, K. Soni, M.W. Schilling, and Aaron Kiess TARGET AUDIENCES: Poultry processors, USDA FSIS, USDA NIFA PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.