Estudo do Circovírus suíno - 2 (PCV2) pelas técnicas de ELISA indireto por captura de anticorpo e PCR em tempo real em suínos

Abstract

Porcine circovirus (PCV) belongs to the Circoviridae family and Circovirus genus. The vírus can be subdivided into porcine circovirus-1 (PCV1) and porcine circovirus-2 (PCV2). PCV1 is non-pathogenic, where as PCV2 is one of the most important etiological agents in the pig industry today, and the cause of several diseases. The complexity of PCV2 caused by disturbances has led to a demand for laboratory techniques and a wider range of biological samples that can facilitate diagnosis and herd health monitoring. Research studies of the antibodies against PCV2 have prefered the ELISA technique to other serological methods because of its simplicity, high sensitivity and specificity. Among the molecular tools, the quantitative real-time polymerase chain reaction (qPCR) stands out since it makes it possible to measure the viral load of the sample. The oral fluid (FO) is a biological sample that has been increasingly used in pig farming as it reduces stress and improves animal welfare. Although PCV2 has been recently detected in Brazil, the North-East region has still not carried out many studies on the dynamics of the respective viruses. In view of this, the, aim of this research is to study PCV2 by means of indirect ELISA with the capture antibody and qPCR in pigs through serum and FO, respectively. The samples were obtained from the Municipal Slaughterhouse in the town of Paulista, located in the metropolitan district of Recife, Pernambuco State. Serum samples were collected during the bleeding process, and a total of 74 samples were obtained. These were assessed by means of the ELISA technique with the capture antibody. The FO samples were obtained from pigs that were housed in stalls to rest. A total of 60 samples were collected, and these were subjected to qPCR testing. The serum samples that were analyzed, had measurements in the ELISA index as follows: very low - 14 (18.92%), low - 13 (17.57%), moderate - 11 (14.86%) and high - 36 (48.65%). The FO samples showed the DNA of the virus as 13.34% (8/60). 75% (6/8) of these had a very low viral load of 4 (log) / ml of the sample and a low viral load 25% (2/8) 4 to 5 (log) / ml sample. The occurrence of antibodies and the presence of PCV2 in the FO samples suggest that the virus is spreading in the herds of Pernambuco State. This study provides a strong argument for the application of ELISA for capture antibody in serological tests and using pids to obtain biological FO samples in quantitative tests.