Transplacental transmission of Neospora caninum in naturally infected small ruminants from northeastern Brazil

Abstract

RESUMO.-[Transmissão transplacentária de Neospora caninum em pequenos ruminantes infectados naturalmente do Nordeste do Brasil.] Toxoplasma gondii e Neospora caninum são reconhecidos como protozoário causadores de aborto em ovinos e caprinos. Desta forma, objetivou-se descrever a transmissão transplacentária desses agentes em pequenos ruminantes na região Nordeste do Brasil. Foram examinados seis fetos caprinos e onze fetos ovinos, totalizando 78 amostras de diferentes tecidos (cé-rebro, fígado, pulmão, rim e coração) provenientes de propriedades rurais com histórico de aborto. As amostras foram analisadas por Reação em Cadeia da Polimerase (PCR), Histopatologia (HP) e Imunohistoquímica (IHQ), com a finalidade de associar o abortamento a T. gondii e/ou N. caninum. Nenhuma amostra foi positiva na PCR e IHQ para T. gondii. Algumas amostras de cérebro, fígado, pulmão, rim e coração de fetos de caprinos e ovinos foram positivas na PCR para N. caninum. Na histopatologia foi observado leve infiltrado mononuclear no fígado e necrose com calcificação no SNC de um caprino, associada à imunomarcação positiva para N. caninum na IHQ e PCR positiva. Os resultados confirmam a transmissão vertical de N. caninum em caprinos naturalmente infectados na região nordeste do Brasil. Toxoplasma gondii and Neospora caninum are causative agents of abortion in sheep and goats. Thus, the present study aimed to describe the transplacental transmission of these protozoans in small ruminants of northeastern Brazil. Seventeen fetuses (6 goats and 11 sheep) from farms with history of abortion were necropsied and samples were collected from different tissues (brain, liver, lung, kidney and heart). The samples were analyzed by PCR, histopathology (HP) and immunohistochemistry (IHC) to evaluate whether T. gondii and/ or N. caninum infection were the cause of abortion. None of the samples was positive for T. gondii according to PCR and IHC results. Some brain, liver, lung, kidney and heart samples of goat fetuses were positive for N. caninum by PCR. In the histopathology, mild mononuclear infiltration and necrosis with calcification were observed in the liver and brain of one goat fetus, respectively, that also was positive for N. caninum by PCR and IHC. The results confirmed vertical transmission of N. caninum in naturally infected goats of northeastern, Brazil.

The Global Prevalence of Neospora caninum Infection in Sheep and Goats That Had an Abortion and Aborted Fetuses: A Systematic Review and Meta-Analysis

“…Among 34 articles, seven examined the prevalence of N. caninum in both sheep and goats. Finally, 27 full texts were reviewed to determine the global status of N. caninum in sheep and goats that had an abortion and aborted fetuses ( 29 – 35 ). In this systematic review and meta-analysis, histopathology and IHC data were only presented, and no analysis was performed on them ( Tables 1 , 2 ).…”

Serological response to Neospora caninum infection in goats and agreement between three diagnostic techniques to detect caprine neosporosis

“…Abortion occurs after pregnant does are inoculated with this protozoan parasite (Lindsay et al 1995, Porto et al 2016. In some countries, reports of abortion and neonatal death in naturally infected goats due N. caninum have been publshed (Barr et al 1992, Dubey et al 1996, Corbellini et al 2001, Eleni et al 2004, Moreno et al 2012, Nunes et al 2017. Abortions occur most often in seropositive goats, and culling is widely practised in eradication programs (Altbuch et al 2012).…”

“…Over the years, neosporosis have been extensively studied in cows as the bovine is the most important farm animal species in economic terms (Reichel et al 2013). Cases of neosporosis in small ruminants have also been reported worldwide, and studies on the transplacental transmission of N. caninum have been conducted by numerous researchers (Dubey & Schares 2011, Varaschin et al 2012, Moreno et al 2012, Nunes et al 2017.…”

Seroprevalence and risk factors associated with Neospora caninum in commercial sheep from northwest of Rio Grande do Sul, Brazil

“…Neospora caninum can lead to abortion or the birth of weakened lambs (Moreno et al, 2012;Razmi & Naseri, 2017), however, transplacental transmission of this parasite in naturally infected small ruminants has been observed in Brazil (Nunes et al, 2017). The presence of anti-N. caninum was detected in 20.3% (61/300) of sheep and in all (13/13) flocks sampled in the northwest of Rio Grande do Sul.…”