Immunologic effects of low levels of ochratoxin A in ovo: utilization of a chicken embryo model.
Ochratoxin A (OA) was administered to 13-day-old chicken embryos via the chorioallantoic membrane. The 7-day LD50 value (day 20 incubation) of OA was calculated at 7.9 micrograms of OA. Ochratoxin-treated embryos (2.5 micrograms) had slight but significant changes in numbers of immunoglobulin-bearing cells in the bursa but not in the spleen. Chicks hatched from in ovo-treated eggs were challenged with 9 X 10(4) colony-forming units (CFU) of beta-hemolytic Escherichia coli (O1:K1) at 7 days of age via the thoracic air sac. Lesion scores of OA-treated chicks were equal to or less severe than those of controls. Hatchmates of the above chicks were vaccinated with a homologous killed E. coli bacterin (O1:K1) at both 2 and 4 weeks of age and challenged with 10(4) CFU of E. coli at 7 weeks. Post-challenge lesions were present in three vaccinated untreated controls and no OA-treated chicks. We conclude that although in ovo exposure to OA may marginally suppress immunoglobulin-bearing cells of bursa, chicks hatched from OA-treated eggs respond as well as controls to an antigen and resist infection by a virulent organism.
Harvey
R B
RB
U.S. Department of Agriculture, Veterinary Toxicology and Entomology Research Laboratory, College Station, Texas 77841.
Kubena
L F
LF
Naqi
S A
SA
Gyimah
J E
JE
Corrier
D E
DE
Panigrahy
B
B
Phillips
T D
TD
D000818:Animals; D002642:Chick Embryo / Q000187:drug effects*; D002645:Chickens / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology; D007136:Immunoglobulins / Q000032:analysis; D007928:Lethal Dose 50; D008954:Models, Biological; D009793:Ochratoxins / Q000008:administration & dosage / Q000494:pharmacology*
D007136:Immunoglobulins; D009793:Ochratoxins; C025589:ochratoxin A