Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 26, 2004
Publication Date: January 26, 2004
Citation: El Balaa, M.F., Adeli, A., McLaughlin, M.R., Rowe, D.E. 2004. Survival of salmonella in broiler litter incubated at different water activity levels [abstract]. International Poultry Scientific Forum. p. 40.
Survival of Salmonella in inoculated broiler litter held at different levels of water activity was determined. Water activity was maintained using: 1) incubation of inoculated litter over saturated salt solutions with defined equilibrium relative humidity in sealed plastic boxes, and 2) using a split flow humidity generator in sealed boxes vented to ambient atmosphere. Inoculated litter samples were incubated at 23 C and 100, 95, 85, 75, 65, 55 and 45% relative humidity in both study systems. Salmonella survival was determined on xylose lysine deoxycholate, and Hektoen enteric agar. Inoculated litter samples were analyzed at daily intervals and survivors expressed as log10 CFU/g of litter. At relative humidity below 75%, Salmonella displayed a biphasic survival pattern, with a rapid initial decline occurring within the first two days of incubation and a death rate ranging between 1.9 and 1.5 log/day. Slower death rates were observed thereafter with times required to reduce the Salmonella count by one order of magnitude ranging between 8 and 40 days. Longer survival times were observed at lower humidity values. At higher humidity values 100 to 85% survival was longer in open flow systems when compared to closed incubation systems using saturated salt solutions. Salmonella persistence was not observed at high relative humidity 100-85%. Greatest Salmonella destruction occurred in closed incubation system over saturated salt solution at high relative humidity (100-85%). Potential application of the research findings in pathogen control requires further scale-up studies.