Serologic profiles for Sarcocystis sp. and Neospora caninum and productive performance in naturally infected beef calves

Abstract

Sarcocystis sp. and Neospora caninum infections affect cattle worldwide causing important economic losses. The objective of the present study was to trace serologic profiles for Sarcocystis sp. and N. caninum in naturally infected beef calves and analyze their relationship with transmission routes and productive performance. Samples were collected in two cow-calf operations located in Buenos Aires province, Argentina. In farm 1, 43 calves were bled and weighed three times. In farm 2, 69 calves were bled and weighed six times. Sarcocystis sp. and N. caninum immunofluorescence antibody test (IFAT) titers were averaged for each sampling point in order to trace serologic profiles for each infection. Categories were created to evaluate differences in daily weight gain. For S. cruzi antigen, animals were separated in a low-titer (< or = 200) and high-titer group (>200); for N. caninum, animals were grouped as infected and uninfected. Sarcocystis sp. antibody titer as well as the number of infected animals increased gradually over time in both farms. In farm 2 the low-titer group had significantly higher daily weight gain than the high-titer group. For N. caninum 44% (farm 1) and 65% (farm 2) of calves were considered infected, and the serological profile was horizontal or decreasing over time. However, seroprevalence increased in both farms and vertical and horizontal transmission frequency were estimated between 18.5%-29% and 22-25.5%, respectively. No differences were detected in daily weight gain between N. caninum groups from both farms. This is the first report of serological profiles for Sarcocystis sp. and N. caninum by IFAT in naturally infected beef calves and their relationship to different transmission routes and productive performance.

Neospora caninum: Seroprevalence in beef cattle in the mountainous region of Santa Catarina, Brazil

“…Such results do not identify whether horizontal or vertical transmission is the primary route of infection and maintenance of N. caninum in beef cattle. Although congenital transmission is considered the most important form of infection for N. caninum in cattle, the results of this study suggests that both vertical and horizontal transmission seem to have equal importance in the epidemiology of infection in beef cattle, similar to a study by Moré et al (2010) in Argentina.…”

Molecular detection of Sarcocystis species in slaughtered sheep by PCR–RFLP from south-western of Iran

“…have very antigenic similarities and therefore they have considerable cross reactions with other Sarcocystis spp. and other related parasites (Moré et al 2010), it is obvious that these serological methods have serious limitations for species diagnosis as well as the genus determination.…”

“…On the other hand, some serological assays including enzyme linked immunosorbent assay (ELISA) and indirect fluorescent antibody test (IFAT), based on bradyzoites derived from sarcocysts have been assessed for serological diagnosis of sarcocystosis in sheep as well as some other animals (Uggla and Buxton 1990;Moré et al 2008;Moré et al 2010). Since, the bradyzoites of different Sarcocystis spp.…”

Aspectos epidemiológicos da infecção por Neospora caninum em bovinos leiteiros da região do Vale do Paraíba Paulista

“…Entretanto, taxa de transmissão vertical menor que 73% foram relatadas em estudos transversais, que não usaram amostras de sangue pré-colostrais (MAINAR-JAIME et al 1999;DYER et al, 2000;BERGERON et al, 2000;ATKINSON et al, 2000;DIJKSTRA et al, 2003;FRANKENA, 2003;PAN et al, 2004;BARTELS et al, 2007;CHANLUN et al, 2007;DIJKSTRA et al, 2008;MORÉ et al, 2009MORÉ et al, , 2010. A mais baixa taxa de transmissão vertical nestes estudos pode ser resultado da ocorrência de transmissão horizontal na vaca ou de seu bezerro após o parto ou declínio do título de anticorpos contra N. caninum abaixo dos níveis de detecção do teste empregado na data do sorodiagnóstico.…”

“…Entretanto, taxas de soroconversão superiores a 22% já foram encontradas (DIJKSTRA et al, 2002b;PFEIFFER et al, 2002;WALDNER et al, 2001a;MORÉ et al, 2010). Hietala e Thurmond (1999) demonstraram que 17 dos 284 bezerros diagnosticados como negativos para N. caninum soroconverteram e permaneceram positivos nos seis anos de duração do estudo, determinando uma taxa de infecção pós-natal de menos de 1% ao ano.…”