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Survival of Salmonella spp. In Waste Egg Wash Water
Citation:
MECKES, M. C., CLIFFORD H. JOHNSON, AND E. W. RICE. Survival of Salmonella spp. In Waste Egg Wash Water. Presented at WEFTEC 2009, Orlando, FL, October 10 - 14, 2009.
Impact/Purpose:
To inform the public.
Description:
The survival of salmonellae under various environmental conditions has been subject of numerous research studies. Due to low densities of these organisms in natural samples, laboratory or clinical cultures were used to ensure that the initial density of salmonellae was sufficiently high in order to observe a response over time. The ability of laboratory cultured strains to survive environmental stresses is unclear. Consequently use of sufficiently high densities of allochthonous organisms should be used for such studies whenever possible. Spent wash waters from chicken egg processing facilities can harbor high densities of bacteria including salmonellae. For this study, total coliforms, E. coli, and Salmonella spp. were enumerated in a egg wash waters discharged from a large egg producer. We then determined how long these organisms would survive under temperature conditions of 5, 15 and 25○ C. Results showed that the fraction of salmonellae surviving over time at a given temperature was comparable to the fraction of indicator organisms which survived. We also found that survival of these organisms varied with temperature with T90 values of 16, 8 and <2 days obtained for Salmonella in spent was water held at 5, 15 and 25○C. Finally, we noted that the response of laboratory derived cultures to environmental stresses mimic the allochthonous microbial population, but individual cells within the allochthonous population may survive for longer periods of time than laboratory cultured strains.
