Horizontal spread of human and poultry-derived strains of Campylobacter jejuni among broiler chicks held in incubators and shipping boxes

The first chick to hatch and dry in each of a series of incubators was fed a suspension of Campylobacter jejuni via a stomach tube and returned to the incubator. Subsequently, all hatched chicks were taken out of the incubators and housed in standard transport boxes for a further 24 h, after which they were killed by carbon dioxide inhalation. The intestinal tracts of all hatched birds were excised, enriched in liquid media and then plated on media selective for C. jejuni. Campylobacters were cultured from up to 70% of the chicks but this percentage varied with the strain originally fed to the initial chick. The spread of poultry-derived strains was as extensive as that of some human-derived strains, while other human strains showed little tendency to spread amongst chicks. A significant number of hatched, healthy chicks had distended intestinal tracts and showed abnormal gross liver pathology. This symptom was typical of those strains of C. jejuni known to be invasive or toxigenic. However, the gross pat...