Molecular characterisation and in vitro virulence phenotypes of Argentinean Neospora caninum bovine isolates

L. M. CAMPERO; M. RUNCO; W. BASSO; G. SCHARES; I. GUAL ; A. DELLARUPE; L. DE FELICE; L. M. ORTEGA-MORA; D. P. MOORE; G. MORÉ; M. C. VENTRUINI

Berlín

Congreso; 5th INTERNATIONAL MEETING on APICOMPLEXAN PARASITES in FARM ANIMALS; 2019

Neospora caninum is an apicomplexan parasite responsible for cattle abortions worldwide. We have obtained two N. caninum isolates (i.e. NC-Argentina LP1 and NC-Argentina LP2) from dairy and beef herds, respectively. The aims of this study were to characterize these isolates by multilocus-microsatellite analysis and to assess their virulence phenotype in vitro. For in vitro studies, 105 VERO cells were grown/well of a culture plate and 104 purified tachyzoites of each isolate were added to each well. NC-Spain7 was used as high virulent control. The parasites were detected using an anti-SAG1-Alexa 488-conjugated monoclonal antibody. Invasion rate (IR) and tachyzoite yield (TY) were estimated. The IR was estimated at 4 h post-infection (p.i.) (IR4h) (after medium change) and at 48 h pi (without medium change) (= total tachyzoite IR [IRT]), both determined as the total number of parasitophorous vacuoles/total well area. For TY studies, 2x105 tachyzoites were cultivated for 48 h. Tachyzoites DNA was extracted and quantified by real-time PCR. Significant differences were detected in pair-wise analysis between IR4h and IRT for the three isolates (p