Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2003
Publication Date: 7/7/2003
Citation: Musgrove, M.T., Jones, D.R., Northcutt, J.K. 2003. Multiple rinses of eggshells for recovery of aerobes and enterobacteriaceae. [abstract] Poultry Science. 81:54.
Technical Abstract: It has been demonstrated that when broiler carcasses are rinsed repeatedly, specific bacterial species can be recovered on later rinses that were recovered on the initial rinse. Though eggshells are less convoluted than chicken skin, they do have numerous pores that are large enough to harbor bacteria. In order to test the ability of rinsing to remove bacteria from shell surfaces, the following experiments were designed. In each of three experiments, eggs were rinsed eight times with 10 ml of phosphate buffered saline. Aliquots of the first, second, fourth, and eighth rinses were plated onto plate count agar and violet red bile agar to enumerate aerobic and Enterobacteriaceae populations. In each of the experiments, half the eggs (five) had been washed and the other half had not been washed (five). Enterobacteriaceae were only recovered from rinses of unwashed eggs with visible feces in the first experiment. All four rinses (1, 2, 4, 8) were positive though average levels (log10 cfu / ml rinse) decreased from 2.8 to 1.2 from the first to the eighth rinse. In all three experiments, for aerobic populations, prevalence decreased with subsequent rinsing. Aerobic organisms were recovered from washed eggs at the following rates: 93, 47, 33, and 20 % for rinses 1, 2, 4, and 8, respectively. Unwashed egg recovery rates were 100, 87, 67 and 53 %. Average aerobic population levels (log10 cfu / ml rinse) for all 3 experiments were 1.4, 0.7, 0.9, and 0.8 for washed eggs and 4.2, 2.9, 2.5, and 2.5 for unwashed eggs. These data indicate that though larger rates of recovery and greater bacterial numbers are observed for the first rinse, subsequent rinses continue to remove organisms. This may indicate that modifications to shell rinse methodology could be improved