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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Poultry Microbiological Safety & Processing Research » Research » Research Project #421037

Research Project: Pathogen Reduction and Processing Parameters in Poultry Processing Systems

Location: Poultry Microbiological Safety & Processing Research

2013 Annual Report

4. Accomplishments
1. A medium was formulated to support aerobic growth of Campylobacter, bacterium associated with processed poultry that is recognized as a major cause of human, bacterial foodborne illnesses. Current methods for growing this pathogen require expensive equipment to produce atmospheres containing less oxygen and more carbon dioxide than normal atmospheres. Initial experiments indicated that supplementing a basal medium composed of tryptose, yeast extract, and a mineral-vitamin solution with organic acids supported the aerobic growth of this pathogen. Additional experiments indicated adding agar and sodium bicarbonate to the media enhanced aerobic growth of Campylobacter. Experiments were conducted to compare growth of the bacteria under aerobic and microaerobic conditions by inoculating the medium with Campylobacter then incubating aerobically or microaerophilically for 72 h at 37C, and enumerating the number of Campylobacter/ml recovered from the media. There was also a 5 to 6 log increase in the number of Campylobacter recovered from media supplemented with fumarate, pyruvate, agar, and NaHCO3 that was inoculated with Campylobacter spp. and incubated aerobically or microaerophilically at 37C for 72 h. Findings indicate that medium might provide an alternative to current procedures of incubating Campylobacter under microaerophilic conditions; thereby, eliminating the additional expense and training required for the use of specialized atmospheres in culturing Campylobacter.

2. Temporal study of pathogen ecology in poultry processing. ARS scientists in Athens, GA demonstrated changes in the bacterial quality of scalder tank water during commercial processing of poultry resulted in the recovery of higher levels food safety-related pathogens from the water within those tanks. Next generation molecular techniques were used to characterize and quantify the bacterial pathogens within these samples, and compare the prevalence of these pathogens to the overall bacterial community and physiochemical characteristics of the processing water. Results of this study will provide data to researchers and commercial processors on the importance of understanding the role of microbial ecology of processing water in controlling poultry food safety-related pathogens in the processing operations.

3. Due to the relatively low commercial value of eggs laid by exotic birds, little information is currently available on the production, fertility, and hatchability of these eggs. Numerous techniques have been examined to increase the fertility and hatchability of eggs of other poultry, however. Since, egg production and performance in some poultry may be improved by adding trace amounts of mineral supplements to feed provided to the poultry, an experiment was designed to test the effects of dietary, organic selenium and zinc on eggs of exotic breeder hens. One hundred twenty hens were separated into 4 treatment groups of 30 hens each, and 3 male birds were added to each group. Birds were provided test diets containing no added minerals, added selenium, added zinc, or added selenium and zinc for 21 day. Eggs were collected daily during the experiment, and the egg production, fertility, hatchability, and embryonic death of the eggs were determined. Results indicated that birds provided a diet supplemented with both selenium and zinc produced more eggs than birds provided other diets. Also, there was less embryonic death in eggs of hens provided a diet supplemented with selenium or a combination of selenium and zinc. There was no difference in the hatchability of the eggs from hens provided either diet, however. Findings of this study indicate that providing exotic birds a diet supplemented with dietary selenium and zinc can improve performance of eggs laid by these hens.

4. Use of in-package ozone generation technology to reduce poultry meat contamination. ARS scientists in Athens GA optimized a novel in-package ozonation technology to reduce bacterial contamination on chicken breast filets. Significant reductions of natural bacterial flora and surface-applied bacterial pathogens (Campylobacter jejuni) were achieved using this novel technology, and this technology is being expanded to include major food quality (Pseudomonas fluorescens) and food safety (Salmonella spp.) microorganisms. Results of this study will provide commercial processors to significantly reduce bacterial pathogens and other bacterial flora on packaged breast filets therefore increasing the quality and safety of the final product as it leaves the processing plant.

5. Development and validation of a Campylobacter genus level qPCR assay. ARS scientists in Athens, GA, developed, optimized, and validated a qPCR assay that specifically targets the Campylobacter genus from a variety of environmental samples. The assay was validated against 16 Campylobacter strains covering major and minor species and the specificity and detection limit of this assay against those strains was determined. The recovery accuracy of this assay was determined through the use of pre-defined combinations of different Campylobacter strains using both cultures and spiked environmental samples. The results of this study will provide researchers with a molecular tool, when used in conjunction with species-specific qPCR assays, to validate culture-based anecdotal information related to the distribution of Campylobacter species in different environmental samples, and provide a new tool to track Campylobacter populations within the environment.

Review Publications
Rothrock Jr, M.J., Szogi, A.A., Vanotti, M.B. 2013. Recovery of ammonia from poultry litter using flat gas permeable membranes. Journal of Waste Management. 33(6):1531-1538.

Hiett, K.L., Cox Jr, N.A., Rothrock Jr, M.J. 2013. Polymerase chain reaction detection of naturally occurring Campylobacter in commercial broiler chicken embryos. Poultry Science. 92(4):1134-1137.

Sundaram, J., Park, B., Hinton Jr, A., Lawrence, K.C., Kwon, Y. 2013. Detection and differentiation of salmonella serotypes using surface enhanced Raman scattering (SERS) technique. Journal of Food Measurement & Characterization. 7(1):1-12.

Hinton Jr, A. 2013. Aerobic growth of campylobacter in media supplemented with C3-monocarboxylates and C4-dicarboxylates. Journal of Food Protection. 76:685-690.

Stanley, V.G., Hickerson, K., Daley, M.B., Hume, M.E., Hinton Jr, A. 2012. Single and combined effects of organic selenium and zinc on egg, fertility, hatchability, and embryonic mortality of exotic cochin hens. Agrotechnology. 2(1):106. doi:10.4172/2168-9881.1000106.

Hiett, K.L., Rothrock Jr, M.J., Seal, B.S. 2013. Characterization of the Campylobacter jejuni cryptic plasmid pTIW94 recovered from wild birds in the southeastern United States . Plasmid Journal. 70:268-271.