Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: 12/15/2005
Publication Date: 1/23/2006
Citation: Shaw, J., Musgrove, M.T., Sheppard, M., Jones, D.R. 2006. Survey of enterobacteriaceae contamination of nest run egg carts in shell egg processing facilities. Poultry Science. 85(1):161-162
Technical Abstract: Enterobacteriaceae are frequent contaminants of food and several members of this bacterial family are human pathogens. High levels in the processing plant environment can be an indication of inadequate sanitation. This experiment was designed to determine if nest run egg carts serve as reservoirs for Enterobacteriaceae. Eggs that are produced by hens not housed in buildings connected to the processing plant are referred to as nest run. These eggs are transported to the plant on carts to be processed. Two plants in the Southeastern United States were sampled. On each visit, five shelves on each of five carts were sampled (n=50/visit). A 12 x 12 cm area on each shelf was swabbed with a sterile gauze pad moistened with phosphate buffered saline and transported on ice back to the laboratory. Enterobacteriaceae were enumerated using violet red bile glucose agar incubated at 37oC for 24 h. Two randomly selected isolates from each positive sample were re-cultured three times to assure clonality and were then identified biochemically. There was 100% prevalence for Enterobacteriaceae at plant A with an average 4.0 log cfu/mL swab diluent. Plant B had 80% prevalence for Enterobacteriaceae with an average 3.1 log cfu/mL swab diluent. Of the 140 isolates analyzed, the most common genera identified were Escherichia spp., Enterobacter spp., Klebsiella spp., Citrobacter spp., Hafnia spp., Kluyvera spp., Leclercia spp., and Salmonella spp. Pseudomonas spp. was the only non-Enterobacteriaceae identified by our methods. This work demonstrates that nest run egg carts serve as reservoirs for Enterobacteriaceae in the shell egg processing environment.