Characterization of a Swedish bovine isolate of Neospora caninum.
The brain of a stillborn calf, seropositive to Neospora caninum and born to a seropositive cow, was homogenized and cultured on Vero cells, where growth of Neospora-like tachyzoites was detected after 8 weeks. The ultrastructural features of the new isolate (Nc-SweB1) corresponded to those of previously published Neospora isolates. In indirect immunofluorescence tests, antigens on Nc-SweB1 tachyzoites were recognized by antibodies raised to a canine N. caninum isolate (Nc-1) but not by antibodies to Toxoplasma gondii, Sarcocystis cruzi, S. tenella, Eimeria alabamensis, Babesia divergens, or B. motasi. Immunoblot analyses revealed no major antigenic difference between Nc-SweB1 and Nc-1, whereas several differences were seen between Nc-SweB1 and protozoa related to N. caninum. The sequences of 16S-like rRNA and the internal transcribed spacer 1 of Nc-SweB1 revealed complete homology with corresponding sequences of two canine N. caninum isolates. Thus, no dissimilarity between Nc-SweB1 and the canine isolates was found, confirming that Nc-SweB1 is N. caninum and suggesting that Neospora-like organisms isolated from cattle are indeed N. caninum.
Stenlund
S
S
Department of Parasitology, National Veterinary Institute, Uppsala, Sweden.
Björkman
C
C
Holmdahl
O J
OJ
Kindahl
H
H
Uggla
A
A
D000818:Animals; D000953:Antigens, Protozoan / Q000032:analysis; D015153:Blotting, Western; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology*; D002522:Chlorocebus aethiops; D003048:Coccidiosis / Q000469:parasitology / Q000662:veterinary*; D004285:Dogs; D019084:Fluorescent Antibody Technique, Indirect; D018688:Neospora / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000648:ultrastructure; D012336:RNA, Ribosomal, 16S; D011817:Rabbits; D013548:Sweden; D014709:Vero Cells
D000953:Antigens, Protozoan; D012336:RNA, Ribosomal, 16S