Humoral and cellular immune response and transplacental transmission in cows experimentally infected with Neospora caninum NC-6 Argentina strain

BACIGALUPE D; CASPE G; BASSO W; MORÉ G.; CAMPERO L; MOORE D.P; VENTURINI L; CAMPERO C; VENTURINI M.C

Calgary, Canadá

Congreso; World Association for the Advancement of Veterinary Parasitology, Calgary, Canada; 2009

World Association for the Advancement of Veterinary Parasitology

Humoral and cellular immune response and transplacental transmission in cows experimentally infected with Neospora caninum NC-6 Argentina strain Bacigalupe D.1, Caspe G.2, Basso W. 1.4, Mor¨¦ G. 1.4, Campero L. 1, Moore D.P. 3.4, Venturini L. 1, Campero C. 3, Venturini M.C. 1 1Laboratorio de Inmunoparasitolog¨ªa, Facultad de Ciencias Veterinarias, UNLP. 60 y 118 (1900) La Plata. dianab@fcv.unlp.edu.ar 2INTA Mercedes. 3 INTA Balcarce 4 CONICET Neospora caninum infection is a major cause of abortion in cattle. The objective of this study was to evaluate the humoral and cellular immune response in cattle during an experimental infection with N. caninum NC-6 Argentina strain and the likelihood of transplacental transmission. Pregnant cows (65 days of gestation) seropositive (SP) and seronegative (SN) to N. caninum were inoculated intravenously with 1 x 108 tachyzoites of NC-6 Argentina strain or PBS as negative control and slaughtered 40 days post-inoculation. Sera were analyzed for N. caninum antibodies by indirect fluorescent antibody test and antibody titer geometric means were analyzed by ANOVA. Blood samples were stimulated in vitro to evaluate gamma interferon (IFN¦Ã) production. Tissues from dams and fetuses were analyzed by PCR for N. caninum DNA. Inoculated animals significantly increased N. caninum antibody titers and IFN¦Ã production respect to controls. One SP cow aborted a SP fetus, and the remaining fetuses were viable. All viable fetuses had histopathologic lesions. The PCR was positive in all fetuses from SN cows and in 2/3 fetuses from SP cows. Neospora caninum DNA characterization is currently underway. No N. caninum DNA was detected in cow brains. This is the first report of experimental infection of cows with a N. caninum isolate from Argentina, and its consequent humoral and cellular immune response and transplacental transmission of the parasite.