Validación de una técnica de RT-PCR en tiempo real para la detección del virus de fiebre aftosa y evaluación de su desempeño en la infección aguda

Abstract

A specific real time reverse transcription polymerase chain reaction (RT-PCRrt) for the detection of foot-and-mouth disease virus was validated using the LightCycler thermocycler 2.0 and its reagents as recommended by the World Organization for Animal Health and was assessed for the detection of the virus in acute infection of cattle experimentally vaccinated and challenged with virus A Argentina/2001 or A24 Cruzeiro. The technique proved to be robust, showing coefficients of variation lower than 4% for different ARN extractions, days or repetitions and was able to detect up to 0,4 TCID 50%, and/or up to 100 RNA molecules. In probang samples, diagnostic sensitivity was 93.1 (95% CI 86.5-96.6) and diagnostic specificity 100 (95% CI 96.3-100). The results of the challenge in vaccinated or multivaccinated bovines showed that although there were high levels of clinical protection in the vaccinated group, FMDV could be detected in all challenged groups. However, detection was 100 times lower in immunized animals.

Immune Response and Partial Protection against Heterologous Foot-and-Mouth Disease Virus Induced by Dendrimer Peptides in Cattle

“…The adjuvant included was the same contained in commercial vaccines. At 38 days postvaccination (dpv), the animals were challenged by nasal instillation with 1 ml (0.5 ml for each nostril) of 10000 of 50% bovine infective doses (BID50) of infective FMDV O1/Campos/Bra/58 (determined by titration on cattle tongue) [ 22 – 26 ]. This method is intended to mimic a natural FMDV infection [ 27 ].…”