TECHNIQUES FOR THE DIAGNOSIS OF NEOSPOROSIS IN A HERD OF DAIRY CATTLE IN SOUTHERN BRAZIL
Notice bibliographique
Résumé
Neosporosis is a protozoal infectious disease caused by the coccidial parasite Neospora caninum. It was found first in tissues of dogs (Dubey et al., 1988) and later naturally occurring in cattle, sheep, goats, deer and horses. Numerous other hosts also have been shown to be experimentally infected. In bovine Neospora caninum is an important cause of abortion in many countries, including Argentina, Australia, Canada, Denmark, UK, Ireland, Israel, Japan, Mexico, the Netherlands, New Zealand, South Africa, Sweden and the U.S.A. It is a worldwide production problem (Dubey, 1999). Two immunological tests were used to detect N. caninum specific antibodies. A commercially-available ELISA kit (enzyme-linked immunosorbent assay; IDEXX Laboratories Inc., Westbrook, Maine, USA) was initially used to assay 172 serum samples (126 cows; 29 heifers; 15 calves; 2 pre-colostral calves) from a dairy herd in Parana State, Brazil. The absorbances were measured at a wavelenght of 620 nm. The serum samples with S/P (sample to positive) ratios of less than 0.50 were classified as negative for Neospora antibodies. If the S/P ratio was greater than or equal to 0.50 the sample was positive. All sera from ELISA positive samples (n=60) and ELISA sero-negative cows (n=11) that had aborted were subsequently tested using the IFAT (indirect fluorescent antibody test). The slides were prepared at the School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin (USA) and used a commercial anti-bovine secondary IgG conjugate (Bovine IgG1,2; VMRD Inc., Pullman, Washington). Test sera were diluted 2-fold at 1:25, 1:50, 1:100 and 1:200 using phosphate-buffered saline (PBS, pH 7.2). Whole parasite fluorescence was considered indicative of the presence of N. caninum antibodies. In each series of ELISA and IFAT performed, positive and negative sera were included as control. Sixty of the 172 (34.8%) were classified as sero-positive for N. caninumspecific antibody. Age-specific ELISA sero-prevalence proportions were 47 of 126 (37.3%) adult cows, 7 of 29 (24%) heifers (1-2 yr), 4 of 15 (27%) heifers (5 mo to 1 yr), and 2 of 2 (100%) pre-colostral samples. The 2 pre-colostral samples were obtained from calves born healthy and whose dams were sero-positive for N. caninum. The ELISA positive samples (60) were positive by IFAT at 1:25 dilution. The IFAT dilutions at 1:50, 1:100 and 1:200 found, respectively, 58, 55 and 42 positive animals. The correlation between ELISA and IFAT was 100% at the dilution of 1:25, and 96.6%, 91.6% and 70%, respectively, for 1:50, 1:100 and 1:200. There was perfect agreement at the lowest dilution (1:25) between IFAT and ELISA performed on 11 sera from cows which had aborted but that had yielded seronegative ELISA results. The sero-positive cows had no reported clinical manifestations of disease other than abortion. The farm recorded 46 abortions, of which 31 (67.3%) were from sero-positive cows. Neosporosis should be considered as a potential cause of abortion by veterinarians, in addition to other abortifacient agents.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».