Recovery of Enterobacteriaceae from shell surface and shell in early mid and late lay

Microbial populations from samples of six pooled eggs were enumerated for Enterobacteriaceae on violet red bile glucose agar (Oxoid, Australia) plates with overlay (purple-red colonies). Presumptive colonies were counted and reported as log cfu/mL of egg rinsate. Translucency tended to be higher in late lay flocks. The Enterobacteriaceae count on the egg shell surface was slightly higher in late lay flocks but was not significantly different from that of the flocks in early lay. 'Salmonella' Infantis was isolated from egg shell rinse. Samples were collected throughout the year 2010-2011. This study is on-going so, as the sample size increases, new insights will be obtained.