The Neospora caninum-Spain 7 isolate induces placental damage, fetal death and abortion in cattle when inoculated in early gestation

Neospora caninum infection during early pregnancy in cattle: how the isolate influences infection dynamics, clinical outcome and peripheral and local immune responses

“…Nc-Spain7 and Nc-Spain8 isolates, which were described as high and low-to-moderate virulence isolates, respectively [21], were selected for comparisons as they showed marked differences in virulence as measured by their capacities to produce disease in the offspring delivery of mice infected by N. caninum during gestation as well as their proliferation capacities in vitro [10,18]. Furthermore, the high virulence of Nc-Spain7 has recently been confirmed in cattle by comparison studies with the NC-1 isolate in a pregnant bovine model [20]. Experimental infections were conducted by inoculating tachyzoites during early pregnancy because previous studies have shown that the most severe clinical consequence, abortion, occurs with infection during this period [6,7,32].…”

“…Notably, by contrast that observed in pregnant mice, both isolates showed the same clinical outcome. In addition, infection in all heifers was also accompanied by early IFN-γ/IL-4 cytokine production under specific PBMC stimulation, a specific IgG response and an upregulation of cytokine mRNA levels in maternal placenta as described previously [6,17,20,32,33,35,36]. Nevertheless, differences in the timing of foetal death, parasite dissemination in maternal and foetal tissues and the kinetics of peripheral and local immune responses were observed depending on the N. caninum isolate used for the infection.…”

“…However, studies in cattle are limited, and it remains unclear if the differences exhibited by N. caninum in vitro and in animal laboratory models could have any repercussions on the outcome of the disease in bovines. An absence of foetal death at day 45 post-infection (pi) in heifers inoculated intravenously at early pregnancy with a low-virulence isolate, Nc-Spain1H, has been reported [19], and differences between two virulent isolates in cattle, Nc-Spain7 and NC-1, were also shown in the timing of foetal death and immunological responses in an early pregnant bovine model [20]. Here, we investigated the pathogenicity of two N. caninum isolates with differential virulence, based on their in vitro invasion and proliferation capacities and to their pathogenicity in pregnant mice [10,18,21], in an early pregnant bovine model.…”

Rhoptry protein 5 (ROP5) Is a Key Virulence Factor in Neospora caninum

“…For N. caninum , various authors have described evidence of different toxicity among isolates. They demonstrated Nc-liv and Nc-Spain 7 had a higher virulence than Nc-1 (Regidorcerrillo et al, 2010; Caspe et al, 2012), and Nc-Spain 2H, Nc-Spain 3H, Nc-Spain 5H, Nc-Spain 6, Nc-Spain 7, and Nc-Spain 9 isolates showed different parasite burdens and brain lesions during the late phase of infection (Pereira et al, 2010). Although among N. caninum isolates, Nc-1 is less virulent in cattle than other isolates, it still leads to nervous system deficiency and deaths (Pan et al, 2014).…”

Markers related to the diagnosis and to the risk of abortion in bovine neosporosis

“…There have been few studies comparing different isolates in vivo (Caspe et al, 2012;Chryssafidis et al, 2014;Regidor-Cerrillo et al, 2014) Regidor-Cerrillo et al (2014 compared two isolates, Nc-Spain7, a high virulence isolate, and NcSpain8, a low-to-moderate virulence isolate on heifers. Although all infected heifers suffered abortion when inoculated early in pregnancy, abortion occurred earlier in those inoculated with Nc-Spain7-infected animals with the parasite being more frequently detected in the placenta and fetuses.…”