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United States Department of Agriculture

Agricultural Research Service

Research Project: MICROBIAL ECOLOGY OF HUMAN PATHOGENS RELATIVE TO POULTRY PROCESSING

Location: Bacterial Epidemiology and Antimicrobial Resistance

2008 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.


3.Progress Report
Progress relates to National Program 108, Food Safety, Component 1.1 Pathogens, Toxins and Chemical Contaminants Preharvest. Sources of Listeria monocytogenes in a poultry processing plant: Sources of the deadly pathogen L. monocytogenes in new food-processing plants is unclear. A new cooked-product plant was monitored for two years for the presence of the organism. Isolates of L. monocytogenes were recovered from the drains as well as from incoming raw product and the surrounding environment and have been subtyped using highly discriminatory DNA fingerprinting techniques. Analysis is under way to determine the relatedness of isolates detected in incoming sources to those detected within the plant and on condemned fully cooked product. These data will allow us to draw conclusions as to what are the most important sources of L. monocytogenes to a poultry further processing plant. Evaluation of a rapid method for detection of Salmonella in poultry carcass rinses: Culture confirmation of Salmonella contamination of poultry takes five days; thus a more rapid method is needed. An innovative method for rapid detection of salmonellae in poultry related samples was tested that includes a bacteriophage treatment phase followed by. a lateral flow test strip specific for salmonellae When compared to standard bacterial culture techniques, the rapid method performed satisfactorily and may be helpful in field test situations where it is advantageous to determine the salmonellae status of samples early in the enrichment scheme to save time and resources. Effect of alternative processing methods on poultry carcass Campylobacter contamination: Leakage of gut contents during feather removal increases contamination of broiler carcasses. Processing techniques designed to reduce carcass exposure to gut contents were tested in the pilot plant and Campylobacter numbers were evaluated. These data are being analyzed and tentatively show that contamination can be lessened by application of innovative processing techniques. Biofilm formation on anti-microbial plastic surfaces: Human pathogens and spoilage organisms can attach and grow on food contact surfaces and an intervention strategy that remains untested has been to add antimicrobial silver ions to plastic food contact surfaces. Research was conducted to examine the effect of antimicrobial sliver additive in plastic cutting boards on the ability of the deadly pathogen Listeria monocytogenes or the spoilage bacteria Pseudomonas putida to form biofilms on the surface of cutting boards. Under the conditions tested, these organisms were capable of forming biofilms on plastic cutting boards regardless of the incorporation of silver ions. Role of protozoa in the ecology of foodborne pathogens. Protozoa live in any wet environment and many feed on bacteria. Ingested bacteria may be killed and digested or they may be adapted to survive in the protozoa, which then protects the bacteria from environmental extremes. A new high-throughput method to analyze survival of Campylobacter in protozoa was developed and tested. This method contributes to the study of pathogens ecology in poultry processing.


4.Accomplishments
1. Effects of poultry processing on Campylobacter populations. Poultry processing is a harsh environment that may select for populations of Campylobacter that are adapted for survival. Several thousand Campylobacter previously collected from broiler carcasses in 20 US broiler processing plants were subtyped by DNA sequence methodology. These data show that the population of Campylobacter on broiler carcasses becomes less diverse as the carcass proceeds through processing plant. Some subtypes of Campylobacter seem to be better suited than others to survive the stresses associated with poultry processing environments. This finding is potentially very useful in our ongoing efforts to determine which characteristics may allow Campylobacter to survive or thrive in the poultry processing ecosystem. This accomplishment relates to National Program 108 Food Safety, Component 1.1 Pathogens, Toxins and Chemical Contaminants Preharvest, Problem Statements 1.1.2 Epidemiology and 1.1.3 Ecology, Host Pathogen and Chemical Contaminants Relationships.

2. Prevalence of Inc A/C Plasmids in Multidrug resistant Salmonella enterica. The origin of new strains of drug resistant bacteria is not understood, but many resistance genes are carried on fragments of DNA known as plasmids that may be exchanged between different strains. The drug resistance and type of plasmids in a panel of Salmonella strains was characterized and apparent evolutionary traits were analyzed. The results indicated that most antibiotic resistance strains probably originated long before modern uses of drugs, so current control methods need to focus on the potential of existing types of strains to spread. This accomplishment relates to National Program 108 Food Safety, Component 1.1 Pathogens, Toxins and Chemical Contaminants Preharvest, Problem Statements 1.1.2 Epidemiology and 1.1.3 Ecology, Host Pathogen and Chemical Contaminants Relationships.


5.Significant Activities that Support Special Target Populations
None.


6.Technology Transfer

Number of Non-Peer Reviewed Presentations and Proceedings3

Review Publications
Ladely, S.R., Harrison, M.A., Cray, P.J., Berrang, M.E., Englen, M.D., Meinersmann, R.J. 2007. Development of Macrolide Resistant Campylobacter in Broilers Administered Subtherapeutic or Therapeutic Levels of Tylosin. Journal of Food Protection. 70(8):1945-1951.

Cox Jr, N.A., Richardson, L.J., Buhr, R.J., Musgrove, M.T., Berrang, M.E., Bright, W. 2007. Bactericidal effect of several chemicals on hatching eggs inoculated with Salmonella serovar Typhimurium. Journal of Applied Poultry Research. 16:(4)623-627.

Meinersmann, R.J., Berrang, M.E., Jackson, C.R., Cray, P.J., Ladely, S.R., Little, E., Frye, J.G., Mattsson, B. 2007. Salmonella, campylobacter and enterococcus spp., their antimicrobial resistance profiles and their spatial relationships in a synoptic study of the upper oconee river basin. Microbial Ecology. 55(3):444-452.

Berrang, M.E., Frank, J.F., Meinersmann, R.J. 2008. Effect of chemical sanitizers with and without ultrasonication on Listeria monocytogenes as a biofilm within polyvinyl chloride drain pipes. Journal of Food Protection. 7(1):66-69.

Berrang, M.E., Meinersmann, R.J., Smith, D.P., Zhuang, H. 2008. The effect of chilling in cold air or ice water on the microbiological quality of broiler carcasses and the population of Campylobacter. Poultry Science. 87(5):992-998.

Last Modified: 4/23/2014
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