Pathological studies in chicken embryos and day-old chicks experimentally infected with Salmonella typhimurium and Staphylococcus aureus
Glávits, R.; Rátz, F.; Fehérvári, T.; Povazsán, J.
Acta Veterinaria Hungarica 32(1-2): 39-49
1984
ISSN/ISBN: 0236-6290 PMID: 6241983 Document Number: 239504
Twenty and ten SPF chick embryos were infected on the 6th day (group A) and on the 14th day (group B) of incubation, respectively, with Salmonella typhimurium and the same numbers of embryos with Staphylococcus aureus. Twenty 1-day-old chicks were infected orally with the same Salmonella, and another 20 with the Staphylococcus, strain (group C). On each day after inoculation, one bird from each group was examined by morphological and microbiological methods. The bacteria, applied at low germ counts (10superscript 3) to the outer surface of the shell membrane, penetrated into the egg and damaged primarily the chorioallantoic membrane (CAM), thus resulting in 10-40% embryonic mortality. The Salmonella produced no, while the Staphylococcus produced occasional, tissue changes in the embryonic organs. As opposed to certain viral infections studied earlier, no morphological signs indicative of cellular or humoral immune response were seen. Day-old chicks infected orally with Salmonella typhimurium developed acute septicaemia, subacute pneumonia, and those infected with Staph. aureus developed arthritis and osteomyelitis. Birds dying in the acute stage showed an atrophy of the lymphoid organs (bursa fabricii, thymus) characterized by depletion of lymphocytes and necrosis, while the lymphoid organs of chicks bled in the subacute stage developed hyperplastic changes.