Humoral immune response to infectious agents in aborted bovine fetuses in Argentina.

The purpose of this study was to characterize the exposure of bovine aborted fetuses from beef and dairy herds of the humid pampas of Argentina to different infectious agents by the evaluation of fetal fluid antibodies. Presence of fetal antibodies to bovine viral diarrhea virus genotype 1 (BVDV-1), bovine herpes virus type 1 (BHV-1), Leptospira interrogans, Brucella abortus, and Neospora caninum was determined. Of the 95 fetuses processed, 66 came from 49 beef herds and 29 from 12 dairy herds. The average gestational age of the aborted fetuses was 7.1 months. Antibodies to the mentioned agents were detected in 65 of the 95 fetal fluids (68.4%). In addition, antibodies to more than one infectious agent were detected in 32 fetuses (33.7%), suggesting fetal exposure to multiple antigens during gestation. There were antibodies to BVDV-1, BHV-1, N. caninum and Leptospira interrogans in 43 (45.2%), 29 (30.5%), 26 (27.4%) and 5 (5.2%) specimens, respectively. Antibodies to B. abortus were not detected in any of the fetal fluids. The results of this study provide information on the determination of antibodies in fluids from bovine aborted fetuses exposed to different infectious agents in the region.

A polymerase chain reaction for detection of equine herpesvirus-1 in routine diagnostic submissions of tissues from aborted foetuses.

Equine herpesvirus 1 (EHV-1) is the causative agent of abortion, perinatal foal mortality, neurological and acute respiratory diseases in horses. Conventional laboratory diagnosis involving viral isolation from aborted foetuses is laborious and lengthy and requires processing of samples within 24 h of collection, which is problematic for samples that come from long distances. The aim of this study was to develop a polymerase chain reaction (PCR) assay useful in Argentina to detect DNA sequences of EHV-1 in different tissues from aborted equine foetuses with variable quality of preservation and without the use of conventional DNA fenolic extraction. Several DNA extraction protocols and primers were evaluated. The amplification method was standardized and its specificity was analysed using 38 foetal samples of variable quality of preservation. Of the 38 different foetal tissues, nine livers, six spleens and two lungs in good preservation and eight livers, one spleen and four lungs in a poor state of preservation were positive for PCR. EHV-1 was recovered only from the nine livers, five spleens and two lungs in good preservation. No virus was isolated from the samples that were poorly preserved. Viral isolation was confirmed by cytopathic effect and indirect immunofluorescence. The specificity of the PCR results was confirmed by the restriction endonuclease digestion of PCR products and hybridization.