Canine distemper in neotropical procyonids: Molecular evidence, humoral immune response and epidemiology.

Canine Distemper Virus (CDV) can produce a fatal multisystem disease in carnivores and other mammals and is an important threat for wildlife conservation. However, integrative and comparative studies in wild carnivores are scarce and some areas of the world lack of genetic studies. We explore the dynamic of host-CDV in a procyonid community during an outbreak. This study reports for the first time an index case occurred in a common raccoon (Procyon lotor) and for which a complete CDV diagnosis was performed. The long-term epidemiological analysis in two sympatric populations of common raccoons and white-nosed coatis (Nasua narica) was achieved through seroneutralization, RT-PCR and direct immunofluorescence assays. Additionally, hematologic analyses were performed and phylogenetic reconstruction of CDV was done using molecular data from this study. Overall prevalence for white-nosed coatis was 19.6 % and for common raccoons was 25.3 % by seroneutralization, and 13.3 % and 17.3 % by RT-PCR. Antibodies titer average for white-nosed coatis was 1:512 and 1:156 for common raccoons. Significant difference in prevalence between white-nosed coatis and common raccoons was detected during one season (summer 2013). White-nosed coatis showed differences in erythrocytes and monocytes counts between positives and negative animals. A 100 % similarity was found between CDV of white-nosed coati and CDV of common raccoon and is a new CDV sequence not previously described; this sequence is close to Asian and European lineage. An endemic state of distemper in both species was observed but showed different dynamics over time per host species. Differences in cellular and humoral responses were also detected between procyonids. The evidence found here may have serious implications for CDV understanding in wild carnivores, it reveals clear differences in the response over time to the same CDV strain, in two close related carnivore species.

Caracterización el virus el Distemper (moquillo canino) en cultivos celulares, aislado de animales clínicamente enfermos / Caracterization of Distemper Virus in cell culture

Se estudió el comportamiento del virus del Distemper Canino (VDC) en cultivos celulares primarios y de líneas. Se emplearon diversos VDC, aislados de encéfalos provenientes de perros que murieron mostrando una sintomatología nerviosa; histológicamente, dichos encéfalos presentaron cuerpos de inclusión y reacción positiva por inmunofluorescencia (IF) al emplear un conjugado anti-DVC. Cada muestra se inoculó en células VERO y Cultivo Primario de Riñón de perro (CRP) para evaluar la capacidad de: a) producir efectos citopáticos (ECP),b) reaccionar frente a un conjugado fluorescente anti-DVC, c) hemoaglutinar glóbulos rojos de diversas especies en diferentes condiciones y d) hemoadsorber glóbulos rojos. Los resultados mostraron que: a) no hubo diferencia alguna entre emplear células VERO y CRP, observándose cambios citopáticos que permitieron diferenciar un cultivo infectado de uno no infectado con virus vacunal, b) el 88 por ciento de las muestras conservó su antigenisidad, pues resultó positivo en la prueba de IF, observándose la mayor intensidad de fluorescencia específica a las 48 horas postinfección, c) el 58 por ciento de las muestras mostró hemoadsorción y d) ninguna muestra, incluyendo los testigos, fue capaz de hemoaglutinar. No fue posible, con base en los resultados, establecer diferencias entre los virus "de campo" y los vacunales.