Serologic responses of cattle and other animals infected with Neospora caninum.
OBJECTIVE
To examine cross-reactivity among Neospora caninum and closely-related apicomplexans.


METHODS
Sera from animals were examined for antibody production to N caninum and cross-reactivity to Toxoplasma gondii.


METHODS
Cattle were experimentally infected with 3 tissue cyst-forming protozoan parasites N caninum, T gondii, and Sarcocystis sp, and calves were monospecifically inoculated with the intestinal coccidia, Eimeria bovis and Cryptosporidium parvum. Similar studies were done in laboratory rabbits inoculated with N caninum, T gondii, Hammondia hammondi, and Sarcocystis sp. Additionally, sera were obtained from ewes, lambs, goats, sows, cats, rats, and mice inoculated with N caninum tachyzoites.


METHODS
The indirect fluorescent antibody (IFA) and ELISA antibody tests (cattle only) were used to examine reactivity to N caninum; the modified direct agglutination, Sabin-Feldman dye, and IFA tests were used to evaluate reactivity to T gondii.


RESULTS
Serologic cross-reactivity among N caninum, T gondii, and Sarcocystis sp was none or minimal by the IFA test. There was some reactivity to N caninum by the use of ELISA in cattle inoculated with Sarcocystis sp.


CONCLUSIONS
The IFA test for N caninum was specific for the diagnosis of neosporosis in animals.
Dubey
J P
JP
USDA, Livestock and Poultry Sciences Institute, Parasite Biology and Epidemiology Laboratory, Beltsville, MD 20705, USA.
Lindsay
D S
DS
Adams
D S
DS
Gay
J M
JM
Baszler
T V
TV
Blagburn
B L
BL
Thulliez
P
P
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000917:Antibody Formation; D002415:Cats; D002417:Cattle; D002460:Cell Line; D002522:Chlorocebus aethiops; D003048:Coccidiosis / Q000097:blood / Q000276:immunology*; D003429:Cross Reactions; D016785:Cryptosporidium parvum / Q000276:immunology; D004539:Eimeria / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006041:Goats; D006801:Humans; D051379:Mice; D018688:Neospora / Q000276:immunology; D011528:Protozoan Infections / Q000097:blood / Q000276:immunology*; D011817:Rabbits; D051381:Rats; D012756:Sheep; D013045:Species Specificity; D013552:Swine; D014709:Vero Cells
D000913:Antibodies, Protozoan