Observations on the pathogenesis of orally inoculated Salmonella typhimurium in a newly hatched broiler chicks

Abstract EN

This study was included experimental infection of newly hatched chicks with Salmonella typhimurium to observe the early events in the pathogenesis of this serotype.

Seventy five newly hatched chicks were divided into 3 groups (G1, G2 and G3).

The first group was challenged via crop instillation with 1 ml of BHI broth containing 9x107 CFU/ml and served as positive control.

The second group was challenged with same dose via drinking water, while the third group was acted as negative control.

Infection has been performed at the 3rd of age.

Both infected groups showed clinical sings started at 3rd and 5th day post-inoculation respectively.

The results of the present study revealed highly significant reduction (P<0.01) in weight gain at 7th, 14th and 21st day post-inoculation in G1 and G2, but there were no significant differences between experimental groups in mortality rate.

Post – mortem examination revealed severe congestion, enlargement and areas of red discoloration with focal areas of necrosis in the liver, catarrhal to mild hemorrhagic enteritis was also recorded in the infected groups.

The study also reveled a carrier state which was represented by re-isolation of bacteria from the cecal content up to 21st day post – infection.