Diagnosis of Neospora caninum in bovine fetuses by histology, immunohistochemistry, and nested-PCR.
Neospora caninum, a cause of abortion and stillbirth in cattle, was studied by histology, immunohistochemistry, and nested-PCR, using primers from the Nc5 region of the genomic DNA (PCR PLUS) and primers from the ITS1 region of the ribosomal DNA (PCR JB). A total of 105 fetal samples sent to the Centro de Pesquisa e Desenvolvimento de Sanidade Animal do Instituto Biológico from January 2006 to May 2008 were examined for evidence of N. caninum. Histological examination revealed 71.4% with non-suppurative inflammation in the heart, lung, liver, kidney, placenta, and brain. Immunohistochemistry detected infections in 8.6% of the samples, mainly in the brain, placenta, and heart. Nested-PCR JB revealed 6.7% with infections, while nested-PCR PLUS returned 20.9% positive results, mainly in brain and placenta, and in the pooled liver and heart. Kappa statistics demonstrated little agreement among the three techniques. The three methods are complementary, since they have distinct diagnostic characteristics and were combined to give a positivity rate of 24.8%.
Cabral
Aline Diniz
AD
Instituto Biológico, Rua Conselheiro Rodrigues Alves 1.252, São Paulo, Brazil. alinedica@netsite.com.br
Camargo
Clarice Neves
CN
Galleti
Nara Thiers Cacciatori
NT
Okuda
Liria Hiromi
LH
Pituco
Edviges Maristela
EM
Fava
Claudia Del
CD
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis*; D003048:Coccidiosis / Q000175:diagnosis / Q000662:veterinary*; D005315:Fetal Diseases / Q000175:diagnosis / Q000662:veterinary*; D007150:Immunohistochemistry; D018688:Neospora; D016133:Polymerase Chain Reaction