Association of Campylobacter jejuni with laying hens and eggs

Abstract

Laying hens were individually caged at 20 wk of age and tested for fecal excretion of C. jejuni (minimum level of detection was 100 colony-forming units/g) during a 42-wk period. Peak rates of C. jejuni isolation (.apprx. 25% of hens positive) occurred at 2 different times, in Oct. and in late April to early May. Communal raising conditions were likely responsible for the high percentage of positive hens in Oct. Before being segregated in late Sept., birds were allowed to consume fecal matter, litter and communal drinking water, all likely sources of C. jejuni. The increased excretion rate in late April may have been due to a climatic change. A small portion (8.1%) of the hens chronically excreted (positive > 30% of the sampling times) the organism, whereas C. jejuni was not detected in 33% of the hens, even though birds were likely exposed to the organism before being segregated. No correlation could be made between rates of C. jejuni excretion and egg production. Of 226 eggs from hens fecally excreting C. jejuni, the organism was isolated from 2 shell surfaces but no egg contents. Egg penetration studies revealed that the organism would not penetrate into the contents of the eggs but could be isolated occasionally from the inner shell and membranes of refrigerated eggs.