2013 Annual Report
1a.Objectives (from AD-416):
1: Derive data and model Salmonella serotype changes in movement from incoming product, through whole bird processing, post-carcass cut-up, to final product.
1A. Develop an exposure assessment (EA) model for Salmonella serotype changes in movement from post-carcass cut-up to final product (cooked chicken parts).
2: Study the survival characteristics for Salmonella serotypes: are there serotypes that survive interventions on farm, in the processing plant and/or final product.
2A. Use the EA model to evaluate efficacy of a plastic chicken house floor for Salmonella serotype control.
3: Derive additional predictive microbiology data of multi-drug resistant (MDR) Salmonella spp., such as Salmonella Typhimurium DT104.
3A. Use MDR Salmonella serotypes to develop the predictive microbiology models needed for the EA model.
1b.Approach (from AD-416):
Predictive microbiology models for contamination, growth and survival of Salmonella serotypes on chicken parts will be developed and linked to form an exposure assessment model that predicts changes in incidence and number of Salmonella serotypes on chicken parts produced by different farm-to-table scenarios. The exposure assessment model will predict consumer exposure to Salmonella serotypes that survive cooking of chicken parts and that cross-contaminate cooked chicken parts during serving. The exposure assessment model will be designed to evaluate effects of interventions on consumer exposure to Salmonella serotypes of chicken origin. The intervention evaluated in the project will be a plastic chicken house floor that has potential to reduce Salmonella serotypes entering the processing plant and surviving on chicken parts after final processing.
A model that predicts consumer exposure to Salmonella from chicken produced by different scenarios is being developed. The model will help regulatory agencies and chicken companies better identify unsafe lots of chicken before they are sold to consumers. This year the model was updated with new data and sub-models (Objective 1). A sub-model for survival and growth of Salmonella on chicken during cold storage was developed and partially validated (Objective 3). Additional data for contamination of chicken parts and cross-contamination of cooked chicken with Salmonella during meal preparation were collected (Objective 2). A robot was purchased that will improve speed and efficiency of data collection.
Short-term freezing of chicken reduces threat of Salmonella. Many consumers buy chicken in bulk and store some in the freezer. ARS and University of Maryland Eastern Shore researchers at Princess Anne, Maryland studied how frozen storage for 6 days affects growth of Salmonella on chicken during meal preparation. They found that short-term freezing injures Salmonella and reduces their growth during meal preparation. Thus, consumer exposure to Salmonella can be reduced by short-term storage of chicken in the freezer before meal preparation.
Antibiotic and chlorine resistance in Salmonella. Treatment of chickens with antibiotics can select for Salmonella that are resistant to antibiotics and other antimicrobials. University of Maryland Eastern Shore and ARS researchers at Princess Anne, Maryland examined effects of antibiotic resistance on resistance to chlorine, which is used to kill Salmonella during chicken processing. They found that antibiotic resistance was not correlated with chlorine resistance. Thus, use of antibiotics on-the-farm will not help Salmonella survive chlorine exposure in the processing plant, which is good news for consumers.
Oscar, T.P. 2013. Initial contamination of chicken parts with Salmonella at retail and cross-contamination of cooked chicken with Salmonella from raw chicken during meal preparation. Journal of Food Protection. 76:(1)33-39.
Oscar, T.P. 2013. Validation of a predictive model for survival and growth of Salmonella Typhimurium DT104 on chicken skin for extrapolation to a previous history of frozen storage. Journal of Food Protection. 76(6):1035-1040.
Oscar, T.P., Rizwana, T., Parveen, S. 2013. Chlorine inactivation of non-resistant and antibiotic resistant strains of Salmonella Typhimurium isolated from chicken carcasses. Journal of Food Protection. 76(6):1031-1034.