Inoculation of a Poultry Isolate Salmonella enteritidis on Egg Vitelline Membrane: Survival and Growth in Egg Components after Different Refrigeration Storage Times
- 1 Texas A&M University Department of Poultry Science, College Station, TX 77843, Venezuela
- 2 Current address: Departamento de Biologia, Facultad Experimental de Ciencias, Universidad del Zulia Maracaibo, Venezuela
- 3 Current address: Dept. of Cardiology, Geffen School of Medicine, University of California Los Angeles, CA 90995, Venezuela
- 4 Current address: Nestlé Purina PetCare, 3916 Pettis Road, St. Joseph, MO, 64503, Venezuela
- 5 USDA-ARS, SPARC, FFSRU, 2881 F&B Road, College Station, TX 77845, Venezuela
- 6 Current address: Center for Food Safety and Microbiology, IFSE, Dept. of Food Science University of Arkansas, Fayetteville, AR 72704-5690, Venezuela
Abstract
An in vitro study was designed to determine the extent of Salmonella enterica serovar enteritidis survival and growth permissiveness in egg components isolated from shell eggs held at refrigeration temperature over an 8 week time period. Eggs were collected from a commercial laying facility at one-week intervals for eight weeks and stored at refrigeration temperature. After storage, eggs were dipped in ethanol, cracked aseptically and separated into yolk and albumen samples. S. enteritidis resistant to novobiocin and nalidixic acid were inoculated on to the surface of the yolk membrane at a concentration of approximately 106 CFU mL-1. Yolks were then covered with albumen and incubated for 24 hrs at 25°C. After incubation, eggs were separated into component parts. Samples were removed from yolk, albumen and yolk membrane and diluted 10-fold in sterile phosphate buffered saline. In albumen, S. enteritidis counts were increased in weeks 3 and 8 compared to week 1 (trial 2). The frequency of eggs exhibiting net growth of S. enteritidis in albumen occurred at week 7 versus weeks 0 and 1 in trial 1 and weeks 3 and 8 versus weeks 0 and 2 in trial 2. In the membrane fraction, the frequency of eggs exhibiting net growth of S. enteritidis occurred at weeks 5 and 8 versus week 0 in trial 2. In the yolk fractions, S. enteritidis counts recovered from week 6 eggs were significantly higher (P<0.05) than those of weeks 0, 2, 3 and 7 (trial 2) and the number of detectable S. enteritidis positive eggs were greater in week 8 than week 5 in trial 1. This suggests that egg components recovered from aged eggs stored at refrigeration temperatures infrequently supported S. enteritidis net growth but generally did not inhibit survivability.
DOI: https://doi.org/10.3844/ajabssp.2007.123.129
Copyright: © 2007 Z.R. Howard, R.W. Moore, I.B. Zabala Diaz, W.K. Kim, S.G. Birkhold, J.A. Byrd, L.F. Kubena, D.J. Nisbet and S.C. Ricke. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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