Vertical transmission of Neospora caninum in Iranian dairy cattle.

Abstract

Placentally, transmission of Neospora caninum plays significant role on retaining of infection and economic losses in dairy farms. The objective of present study was to assess placental transmission of N. caninum in Iranian dairy cattle. A total of 476 blood samples of pregnant dairy cattle were randomly collected for serology test using ELISA technique. Genomic DNA was extracted and subjected for conventional PCR and Nested-PCR to amplify 330bp and 100bp fragment length of NC5 gene, respectively. Positive animals were follow-up during gestation till abortion and/or full term delivery occurred. Molecularly, 25.3% (118/476; 95% CI: 21%-28.6%) of examined animals were seropositive for N. caninum infection in Holstein cattle (15.1%) with <2 years-old (75%) and history of abortion. The infection was detected. TT and abortion occurred in 13.6% and 3.57% of animals, respectively. Aborted cattle (94.1%, 16/17) were significantly infected to N. caninum and history of abortion was recorded in 42.4% of infected cattle. Placental transmission and abortion in naturally infected dairy cattle due to N. caninum was the first molecular evidence in all examined herds of cattle. It was also uncovered N. caninum had significant role on cattle abortion. Further studies for culling of seropositive cattle with history of abortion, associated risk factors related to neosporosis and lunch control program for reducing side effects of infection are essential in the region.