1a. Objectives (from AD-416):
1. Using population genetics, track bacterial migration and adaptation of foodborne pathogens through poultry processing and the associated environment. Evaluate the variations and influence of genetic and strain diversity from animal through the processing plant. 2. Examine the role of protozoa and other potential biological populations in the microbial ecology of foodborne pathogens through poultry processing. 3. Evaluate the potential for protozoa and other biological controls to be used as intervention or mitigation strategies for human pathogens in poultry processing and processing facilities. 4. Based on objectives 1-3, develop and evaluate physical and chemical intervention strategies to reduce contamination by foodborne pathogens of poultry products.
1b. Approach (from AD-416):
The focus of this research would be called the “transmission phase” by epidemiologists or the “migration phase” by ecologists. Processing of poultry products creates many severe barriers to transmission such that most of the pathogens are lost. However, it is clear that the barriers are incomplete and enough pathogens survive and pass to human consumers to cause foodborne disease. It is reasonable to assume that bacteria have adaptive strategies that improve the chances that some clones will survive processing making transmission to humans possible. The objectives of this project are designed to determine the relative ability of genetically different clones of foodborne pathogens to survive barriers that are encountered in the poultry processing plant. This will be followed by studying specific biological barriers that are common to ecosystems and are often responsible for limiting migration of bacteria. It is also likely that protozoa will be found in the processing environment that are not only ineffective in killing pathogens but may even be protective. Therefore, we plan to study the mechanisms of destruction or protection as they are uncovered. The knowledge that is gained from these studies will be used to design enhanced barriers in an attempt to improve the microbiological benefits of poultry processing.
3. Progress Report:
We have previously reported that floor drains in a poultry further-processing plant can harbor strains of Listeria monocytogenes, a bacterial species that can contaminate food and cause disease in humans. Some floor drains continually harbor the organism and others are continually negative. It is known that the wet surfaces in a floor drain have a complex community of microorganisms, but the influence of these organisms on the pathogens is not understood. We performed assays to compare the species that are present in drains that were shown to harbor Listeria with drains that were negative. We identified 83 species of fungi, 70 species of bacteria and 28 species of protozoa. Differences between Listeria-negative and Listeria-positive drains were seen for all three classes, most often exhibited as an increase in the numbers of some species in the Listeria-positive drains. The significance of these differences is being analyzed. Completed a follow up study to measure the contamination of raw meat by airborne drain Listeria and the fate of such contamination on meat during cold storage. This data has been collected and is currently being analyzed. Carried out preliminary work and started data collection on an intervention strategy to kill Listeria on raw poultry meat exposed to airborne cells. Using a previously developed germicidal ultra-violet light method, we treated breast fillets with the low numbers expected to be present due to cross contamination from drain spray. Working with scientists from the Poultry Microbiological Safety Research Unit and an outside company, we tested electroporation technology as a means to sanitize poultry carcasses during slaughter. The method promises limited utility in the current state. The cooperators are working to fine tune the equipment towards best effect. Collected carcass drip samples from commercial processing plants representing approximately 1,500 broiler carcasses per replication. The drip samples are being used to detect Campylobacter, compare a panel of Campylobacter specific growth media to determine the best performer and working with PMS to develop a microbiological census of all bacteria likely to be present on broiler carcasses during slaughter and first processing. Continued to study a proprietary broiler chill water additive designed to maintain the efficacy of chlorine as an antimicrobial even in the presence of organic matter (such as broiler carcasses). This compound was found to limit the number of total aerobic bacteria on carcasses and lessen the amount go cross contamination with human pathogens: Salmonella and Campylobacter. This data is currently being analyzed prior to manuscript production.
Berrang, M.E., Smith, D., Meinersmann, R.J. 2011. Variations on standard broiler processing in an effort to reduce Campylobacter numbers on postpick carcasses. Journal of Applied Poultry Research. 20(2):197-202.