Source: AGRICULTURAL RESEARCH SERVICE submitted to
INTERVENTION AND PROCESSING STRATEGIES FOR FOOD-BORNE PATHOGENS IN SHELL EGGS
Sponsoring Institution
Agricultural Research Service/USDA
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0421227
Grant No.
(N/A)
Project No.
6612-41420-019-00D
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Apr 21, 2011
Project End Date
Feb 27, 2013
Grant Year
(N/A)
Project Director
MUSGROVE M T
Recipient Organization
AGRICULTURAL RESEARCH SERVICE
(N/A)
ATHENS,GA 30613
Performing Department
(N/A)
Non Technical Summary
(N/A)
Animal Health Component
(N/A)
Research Effort Categories
Basic
50%
Applied
50%
Developmental
0%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
71232701100100%
Goals / Objectives
1. Evaluate bactericidal effects of critical processing parameters (e.g. influence of wash water parameters, sanitizers, and sanitizer application methods) on egg safety. Specifically, conduct research on effective sanitizers (chemical, UV, etc.) and parameters that influence efficacy (temperature, nozzle type, etc.): 1.A Determine role of pH in wash water; 1.B Test chemicals as post-wash sanitizers for shell eggs; 1.C Evaluate modifications in post-wash sanitizer delivery. 2. Identify intervention strategies and processing practices for shell egg facilities and equipment that will improve sanitation standard operating procedures and reduce foodborne pathogens: 2.A Identify important reservoirs of Salmonella contamination in the processing environment; 2.B Evaluate sanitation interventions. 3. Develop more sensitive methods of detection and analysis and apply them in the determination and characterization of pathogen flow through the processing environment and onto eggs: 3.A Evaluate rapid, sensitive methods for pathogen detection; 3.B Utilize enhance methods to determine effect of housing on egg microbiology; 3.C: Characterize isolates at the molecular level to demonstrate flow from production through processing.
Project Methods
This project will promote egg safety by improving processing and intervention strategies in three critical areas. First, the bactericidal effects of critical processing parameters will be determined. Commercial egg wash detergents do an excellent job of cleaning eggs but are less lethal to bacteria when wash water pH is <10. Currently, the sanitizing chlorine solution sprayed onto eggs after washing does not reduce bacterial numbers. Research is needed to document the importance of pH and to identify an effective post-wash egg sanitizer. Second, improved sanitation procedures within processing facilities will be developed. Producing safe food requires a clean processing environment. Documentation is needed of areas and equipment in the processing facility most often contaminated with Salmonella. Such information will assist in development of effective means of removing or killing harmful bacteria. Third, better methods for detecting pathogens in egg processing environments and eggs will be developed. A recent new law requires egg producers to test for Salmonella Enteritidis (SE) in houses and flocks. Rapid, objective tests specific for SE will enable the egg industry in complying with this rule. Analyzing DNA from Salmonella collected at farms, processing facilities, and eggs allow for tracking of important contamination sources. Also, improved testing methods are required for a scientifically-based assessment of how different housing types affect egg microbiology.

Progress 04/21/11 to 02/27/13

Outputs
Progress Report Objectives (from AD-416): 1. Evaluate bactericidal effects of critical processing parameters (e.g. influence of wash water parameters, sanitizers, and sanitizer application methods) on egg safety. Specifically, conduct research on effective sanitizers (chemical, UV, etc.) and parameters that influence efficacy (temperature, nozzle type, etc.): 1.A Determine role of pH in wash water; 1.B Test chemicals as post-wash sanitizers for shell eggs; 1.C Evaluate modifications in post-wash sanitizer delivery. 2. Identify intervention strategies and processing practices for shell egg facilities and equipment that will improve sanitation standard operating procedures and reduce foodborne pathogens: 2.A Identify important reservoirs of Salmonella contamination in the processing environment; 2.B Evaluate sanitation interventions. 3. Develop more sensitive methods of detection and analysis and apply them in the determination and characterization of pathogen flow through the processing environment and onto eggs: 3.A Evaluate rapid, sensitive methods for pathogen detection; 3.B Utilize enhance methods to determine effect of housing on egg microbiology; 3.C: Characterize isolates at the molecular level to demonstrate flow from production through processing. Approach (from AD-416): This project will promote egg safety by improving processing and intervention strategies in three critical areas. First, the bactericidal effects of critical processing parameters will be determined. Commercial egg wash detergents do an excellent job of cleaning eggs but are less lethal to bacteria when wash water pH is <10. Currently, the sanitizing chlorine solution sprayed onto eggs after washing does not reduce bacterial numbers. Research is needed to document the importance of pH and to identify an effective post-wash egg sanitizer. Second, improved sanitation procedures within processing facilities will be developed. Producing safe food requires a clean processing environment. Documentation is needed of areas and equipment in the processing facility most often contaminated with Salmonella. Such information will assist in development of effective means of removing or killing harmful bacteria. Third, better methods for detecting pathogens in egg processing environments and eggs will be developed. A recent new law requires egg producers to test for Salmonella Enteritidis (SE) in houses and flocks. Rapid, objective tests specific for SE will enable the egg industry in complying with this rule. Analyzing DNA from Salmonella collected at farms, processing facilities, and eggs allow for tracking of important contamination sources. Also, improved testing methods are required for a scientifically-based assessment of how different housing types affect egg microbiology. A commercial facility was modified to include 3 types of housing systems for laying hens (traditional cages, aviaries, and enriched cages), and environmental samples were collected from each type of housing. Areas sampled included egg belts, cage wiring, manure belts, egg ramps/ elevators, nest area, roosts, and drag swabs of floors. Flies and rodents were sampled intermittently.Total aerobic microorganisms and Enterobacteriaceae were enumerated in these environmental samples and the presence of Salmonella and Campylobacter was determined by selective enrichment. Salmonella and Campylobacter recovery was similar for traditional and aviary systems and lowest in enriched systems. After the last monthly samples were collected and the flocks were depopulated, the houses were re-sampled to determine the efficacy of cleaning procedures. Pathogens were not recovered after disinfection procedures were performed. Environmental and egg samples were collected from an associated egg processing facility. Environmental samples included rollers, trays, transport equipment (spindles and belts), brushes, tank drains, and egg waste buckets. None of the environmental swab samples were positive for Salmonella or Campylobacter and overall bacterial counts were low. Pooled egg slurry prepared from unwashed eggs laid by traditionally caged hens was positive for Salmonella, but no pathogens were recovered from washed eggs from any housing type (including floor eggs from the aviary system). Environmental and egg wash water samples were tested from another egg processing facility. Temperature and pH readings were recorded for wash water. The environmental samples most likely to yield positive results for Salmonella were drains, farm belts, accumulator belts, packer head brushes, clam shells, accumulator belts, and wash tanks. Eggs designated for breaker facilities were more likely to be contaminated than those intended for retail sale as shell eggs. Salmonella prevalence was highest when wash water pH was below 10.5.

Impacts
(N/A)

Publications


    Progress 10/01/11 to 09/30/12

    Outputs
    Progress Report Objectives (from AD-416): 1. Evaluate bactericidal effects of critical processing parameters (e.g. influence of wash water parameters, sanitizers, and sanitizer application methods) on egg safety. Specifically, conduct research on effective sanitizers (chemical, UV, etc.) and parameters that influence efficacy (temperature, nozzle type, etc.): 1.A Determine role of pH in wash water; 1.B Test chemicals as post-wash sanitizers for shell eggs; 1.C Evaluate modifications in post-wash sanitizer delivery. 2. Identify intervention strategies and processing practices for shell egg facilities and equipment that will improve sanitation standard operating procedures and reduce foodborne pathogens: 2.A Identify important reservoirs of Salmonella contamination in the processing environment; 2.B Evaluate sanitation interventions. 3. Develop more sensitive methods of detection and analysis and apply them in the determination and characterization of pathogen flow through the processing environment and onto eggs: 3.A Evaluate rapid, sensitive methods for pathogen detection; 3.B Utilize enhance methods to determine effect of housing on egg microbiology; 3.C: Characterize isolates at the molecular level to demonstrate flow from production through processing. Approach (from AD-416): This project will promote egg safety by improving processing and intervention strategies in three critical areas. First, the bactericidal effects of critical processing parameters will be determined. Commercial egg wash detergents do an excellent job of cleaning eggs but are less lethal to bacteria when wash water pH is <10. Currently, the sanitizing chlorine solution sprayed onto eggs after washing does not reduce bacterial numbers. Research is needed to document the importance of pH and to identify an effective post-wash egg sanitizer. Second, improved sanitation procedures within processing facilities will be developed. Producing safe food requires a clean processing environment. Documentation is needed of areas and equipment in the processing facility most often contaminated with Salmonella. Such information will assist in development of effective means of removing or killing harmful bacteria. Third, better methods for detecting pathogens in egg processing environments and eggs will be developed. A recent new law requires egg producers to test for Salmonella Enteritidis (SE) in houses and flocks. Rapid, objective tests specific for SE will enable the egg industry in complying with this rule. Analyzing DNA from Salmonella collected at farms, processing facilities, and eggs allow for tracking of important contamination sources. Also, improved testing methods are required for a scientifically-based assessment of how different housing types affect egg microbiology. After preliminary sampling of a single facility the samples most likely to yield Salmonella positives were determined: drains, farm belts, accumulator belts, packer head brushes, clam shells, accumulator belts, and wash tanks. Eggs designated for breaker facilities are more likely to be contaminated than those for retail shell eggs. It is also important to take wash water temperature and pH measurements. It was observed that Salmonella prevalence was highest when pH was below 10.5. Contact was made with a company that produces a chlorine adjuvant. This compound increases the pH range of effectiveness and also minimizes the effect of organic matter in inactivating chlorine compounds. This compound will be used in testing egg sanitizing before and after washing. Escherichia coli cultures isolated from shell eggs were sent to a collaborator at the University Of Minnesota Medical School. These cultures are being analyzed and compared to clinical isolates implicated in human disease. The first production cycle was completed for hens in traditional cages, aviary, and enriched cages. Monthly sampling was completed on eggs and environmental samples from each type of housing to determine effects of housing on microbiological impact. Aerobic microorganisms and Enterobacteriaceae were enumerated while samples were enriched for Salmonella and Campylobacter. Salmonella and Campylobacter recovery was similar for traditional and aviary systems and lowest in enriched systems. On a quarterly basis, the same populations were monitored for washed eggs and for processing facility environmental samples. Counts and pathogen prevalence were low for environmental samples after eggs were washed. No pathogens were recovered from washed eggs regardless of housing type, including floor eggs from the aviary system. After the last monthly samples were collected in June, the houses were re-sampled to determine the efficacy of cleaning procedures. As houses were depopulated no eggs were sampled. Pathogens were not recovered after disinfection procedures were performed. Accomplishments 01 Effects of housing on egg microbiology. While the layer hen production environment is known to contribute to the microbial quality of shell egg it is more important to consider any residual effects after processing h been completed. Eggs from traditional cages, aviary, enriched cages, an eggs from the floor of aviary housing were sampled before and after processing (washed as required for retail shell eggs). None of the wash eggs was contaminated with Salmonella or Campylobacter and counts for aerobic microorganisms and Enterobacteriaceae were very low. This indicates that the commercial process is sufficient for decreasing shell contamination of eggs, regardless of where they are collected. Includin floor eggs for shell egg producers that use an aviary style of housing c add to profits. This data shows that there is not a significant effect shell egg safety based on housing.

    Impacts
    (N/A)

    Publications

    • Musgrove, M.T., Northcutt, J. 2012. Evaluation of an alcohol-based sanitizer spray's bactericidal effects on Salmonella inoculated onto stainless steel and shell egg processing equipment. International Journal of Poultry Science. 11(2):92-95.


    Progress 10/01/10 to 09/30/11

    Outputs
    Progress Report Objectives (from AD-416) 1. Evaluate bactericidal effects of critical processing parameters (e.g. influence of wash water parameters, sanitizers, and sanitizer application methods) on egg safety. Specifically, conduct research on effective sanitizers (chemical, UV, etc.) and parameters that influence efficacy (temperature, nozzle type, etc.): 1.A Determine role of pH in wash water; 1.B Test chemicals as post-wash sanitizers for shell eggs; 1.C Evaluate modifications in post-wash sanitizer delivery. 2. Identify intervention strategies and processing practices for shell egg facilities and equipment that will improve sanitation standard operating procedures and reduce foodborne pathogens: 2.A Identify important reservoirs of Salmonella contamination in the processing environment; 2.B Evaluate sanitation interventions. 3. Develop more sensitive methods of detection and analysis and apply them in the determination and characterization of pathogen flow through the processing environment and onto eggs: 3.A Evaluate rapid, sensitive methods for pathogen detection; 3.B Utilize enhance methods to determine effect of housing on egg microbiology; 3.C: Characterize isolates at the molecular level to demonstrate flow from production through processing. Approach (from AD-416) This project will promote egg safety by improving processing and intervention strategies in three critical areas. First, the bactericidal effects of critical processing parameters will be determined. Commercial egg wash detergents do an excellent job of cleaning eggs but are less lethal to bacteria when wash water pH is <10. Currently, the sanitizing chlorine solution sprayed onto eggs after washing does not reduce bacterial numbers. Research is needed to document the importance of pH and to identify an effective post-wash egg sanitizer. Second, improved sanitation procedures within processing facilities will be developed. Producing safe food requires a clean processing environment. Documentation is needed of areas and equipment in the processing facility most often contaminated with Salmonella. Such information will assist in development of effective means of removing or killing harmful bacteria. Third, better methods for detecting pathogens in egg processing environments and eggs will be developed. A recent new law requires egg producers to test for Salmonella Enteritidis (SE) in houses and flocks. Rapid, objective tests specific for SE will enable the egg industry in complying with this rule. Analyzing DNA from Salmonella collected at farms, processing facilities, and eggs allow for tracking of important contamination sources. Also, improved testing methods are required for a scientifically-based assessment of how different housing types affect egg microbiology. Samples were collected from 4 layer breeder farms and enriched to recover Salmonella and Campylobacter. A single Salmonella positive was recovered from a fecal sample. Campylobacter was recovered from feces, oviduct, and drag swabs, all from two breeder farms. A commercial facility was modified to include three types of housing systems for layer hens: traditional cages, aviary style, enriched cages, which were sampled to determine a baseline of Salmonella and Campylobacter contamination prior to hen placement. Swabs of cages, egg belts, manure belts, and floors were performed. Only the traditional cages and belts were contaminated with Salmonella. None of the samples were positive for Campylobacter. Environmental samples were collected from hens in layer houses using traditional cages, aviary, or enriched cages. Areas sampled included egg belts, cage wiring, manure belts, egg ramps/elevators, nest area, roosts, and drag swabs of floors. Fly and rodents were sampled intermittently. From May through July; 17, 13, and 6 Salmonella positive samples were recovered from traditional, aviary, and enriched caging systems, respectively. Two fly samples from the aviary barn were also positive for Salmonella. In the same time period 8, 41, and 24 Campylobacter positive samples were recovered from traditional, aviary, and enriched caging systems, respectively. Eggs were collected from cages and from the floor. No eggs were positive for either Salmonella or Campylobacter. On a single visit to an egg processing facility, environmental, water, and egg samples were collected. Environmental sampling including, rollers, trays, transport equipment {spindles, belts}, brushes, tanks drains, and egg waste buckets. Temperature and pH readings were recorded for wash water. Eggs from each of the housing systems were collected and sampled before and after washing. None of the environmental swab samples were positive for Salmonella or Campylobacter. Pooled egg slurry prepared from unwashed eggs laid by traditionally caged hens, was positive for Salmonella. Campylobacter was recovered from pooled slurry prepared from washed eggs laid by hens housed in the enriched cages. This project replaced 6612-41420-018-00D. Significant Activities that Support Special Target Populations The facility where eggs from the three types of housing are processed is minority owned.

    Impacts
    (N/A)

    Publications

    • Hannah, J.F., Wilson, J.L., Cox Jr, N.A., Cason Jr, J.A., Bourassa, D.V., Richardson, L.J., Musgrove, M.T., Rigsby, L.L., Buhr, R.J. 2011. Comparison of shell bacteria from unwashed and washed table eggs harvested from caged laying hens and cage-free floor-housed laying hens. Poultry Science. 90(7):1586-1593.