Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: 4/18/2006
Publication Date: 7/16/2006
Citation: Jones, D.R., Musgrove, M.T. 2006. Prevalence of salmonella, campylobacter and listeria on the surface of vacuum loaders in shell egg processing plants. Poultry Science.85(1):134-135
Technical Abstract: Previous studies have examined the effectiveness of sanitation programs in shell egg processing facilities. The results showed vacuum loaders to be a reservoir of high levels of aerobic bacteria and Enterobacteriaceae. This study was conducted to determine the prevalence of Salmonella, Campylobacter and Listeria on the surface of the suction cups from the vacuum loaders. Two shell egg processing facilities were sampled (one offline, one mixed operation) on three occasions each (weekly). One third of the suction cups (20 per visit) were randomly selected for sampling each visit with the aid of a random number table. Cups were removed from the vacuum loader and placed in a sterile sample bag with 50 mL of sterile phosphate buffered saline. Cups were rinsed for one minute before being returned to the vacuum loader. Rinsates were transported on ice to the laboratory for analysis. Total aerobic populations and Enterobacteriaceae were enumerated. Appropriate methodology was utilized to determine the prevalence of Salmonella, Campylobacter and Listeria. Aerobic population and Enterobacteriaceae levels were similar to those determined in the previous sanitation studies (5.5 and 2.3 log cfu/mL, respectively). There was no Campylobacter found on the vacuum loaders. Less than 10% of the samples were positive for Salmonella. There was a very high incidence of Listeria found on the suction cup surfaces. Biochemical tests confirmed presumptive isolates to be L. innocua and L. monocytogenes. These results indicate that additional research is needed to improve the cleaning and sanitation procedures for suction cups on vacuum loaders to reduce the incidence of these pathogens in the shell egg processing environment.