2010 Annual Report
1a.Objectives (from AD-416)
1)Determine the role that outside environmental sources of Listeria monocytogenes play in the presence of this pathogen in poultry further processing facilities. 2)Develop and test intervention strategies to eliminate L. monocytogenes and Campylobacter from meat products or processing plant surfaces. 3)Evaluate gene expression profiles of L. monocytogenes and C. jejuni in conditions relevant to poultry processing environments. 4)Evaluate the influence of animal agriculture on Campylobacter in the environment.
1b.Approach (from AD-416)
Poultry products are commonly associated with the human pathogens Campylobacter and Listeria. The processing plant is a post-harvest site in which numerous manipulations are made to the poultry product, many of which may impact the microbial quality of the product. This research project is designed to study the distribution and dispersion of bacterial pathogens in poultry processing plants and poultry products. The goal is to develop information so that knowledge-based methods can be developed to improve the microbiological quality of poultry products. Sub-types of organisms will be studied to determine if they are specific for the poultry processing ecosystems from which they are derived. Gene expression will be examined in order to find genes that are regulated in response to environmental conditions or are growth phase specific. As work progresses, the results of these efforts may uncover possibilities for definition of critical control points or potential intervention strategies.
The complete transmission cycle of Campylobacter jejuni remains unknown. Transmission in water is a potential mechanism. C. jejuni has been collected for five years in an ecological study on microbial populations in water ways of the Oconee river basin. One large yearly (85 site) and three quarterly collections were conducted. Eighty-three independent isolates of C. jejuni have been recovered that are now being characterized by multi-locus sequence typing (MLST). This data will tell us if the populations of Campylobacter found in open waterways communicate with populations found in agricultural products, notably chickens.
We have previously shown that vent-emptying during evisceration of poultry contributes to carcass contamination. This may be controlled by changes in processing. A study was undertaken to determine the affect of alternate broiler carcass positioning/orientation during processing and order of processing events on the numbers of Campylobacter. The study was designed to test means for preventing the increase in Campylobacter numbers normally encountered during feather removal. Much of the data has been collected and is currently being analyzed.
Broiler transport to processing plants has been identified as a possible point of cross-contamination. A study is underway to test the use of mechanical drying to rapidly lower the moisture in feces left in broiler transport cages. The desired result is a drastically lessened number of Campylobacter and lower risk of flock to flock transfer of human pathogens during live broiler transport.
Floor drains are a site for long-term residency of pathogens that may contaminate meat. A study was started which involves examining bacteria in floor drains in poultry further processing plants. We are in the process of identifying drains that are commonly associated with Listeria monocytogenes and those that are not. We hope to study co-habiting microbes to learn more about microbial ecology in floor drain systems.
A study was completed to examine the utility of chlorine dioxide to lessen the contamination of broiler carcasses with Campylobacter during feather removal. In cooperation with a commercial processor, chlorine dioxide was generated onsite and applied through existing plumbing in automated feather picking machines as a spray. This was designed to combat the increase in Campylobacter numbers generally encountered during automated feather removal. The chlorine dioxide treatment significantly moderated the increase in Campylobacter, E coli and Salmonella detected on treated carcasses compared to control carcasses.
A study was completed to measure the microbiological affect of a high pH scald tank and a post defeathering chlorine dip tank on broiler carcass bacteria. With a commercial cooperator, replicate flocks were split between treated and untreated scald tank lines. The high pH scald (mean pH 9.89) was more effective to lessen numbers of Campylobacter than the control scald tank. No such effect was noted for numbers of E. coli or the prevalence of Salmonella. The improvement noted during high pH scald was not maintained during the post defeathering dip tank.
A study was completed in collaboration with Cornell University to evaluate the evolutionary history of Campylobacter coli using microarray comparative genomic analysis and an expanded multi-locus sequence typing (MLST) scheme. Even though populations of C. coli can be observed to share DNA by recombination, population structures could be seen that correlated with the animal source of the bacterial isolates as well as the geographic source of the isolates. Human isolates showed the most overlap with the population from chickens.
Lloyd, T., Alvarado, C.Z., Brashears, M.M., Thompson, L.D., Mckee, S.R., Berrang, M.E. 2009. Control of Listeria monocytogenes in Turkey Deli Loaves using Organic Acids as Formulation Ingredients. Poultry Science. 88(10):2235-2239.
Shak, J.R., Dick, J.J., Meinersmann, R.J., Perez-Perez, G.I., Blaser, M.J. 2009. Repeat-associated plasticity in the Helicobacter pylori RD Gene Family. Journal of Bacteriology. 191(22):6900-6910.
Berrang, M.E., Meinersmann, R.J., Frank, J.F., Ladely, S.R. 2010. Colonization of a Newly Constructed Commercial Chicken Further Processing Plant with Listeria monocytogenes. Journal of Food Protection. 73(2):286-291.
Williams, M., Ebel, E., Golden, N., Berrang, M.E., Bailey, J.S., Hartnett, E. 2010. Estimating removal rates of bacteria from poultry carcasses using two whole-carcass rinse volumes. International Journal of Food Microbiology. 139(3):140-146.
Berrang, M.E., Frank, J., Meinersmann, R.J. 2010. Listeria monocytogenes Biofilm Formation on Silver Ion Impregnated Cutting Boards. Food Protection Trends. 30(3): 168 - 171.
Lang, P., Lefebure, T., Wang, W., Pavinski Bitar, P., Meinersmann, R.J., Kaya, K., Stanhope, M.J. 2010. Expanded MLST genotyping and comparative genomic hybridization evidence for host preferred groups in Campylobacter coli. Journal of Bacteriology. 76(6):1913-1925.