Molecular detection of classical swine fever from a field outbreak in Tamil Nadu

Classical swine fever (CSF) is an economically important viral disease of swine, characterised by high fever and multiple haemorrhages. The paper describes molecular detection of swine fever from a field outbreak in a small piggery unit in Tamilnadu, based on histopathology, virus isolation and 5’UTR and E2 nested primer based reverse transcriptase PCR. The 5’UTR specific primers resulted in 138 bp amplicon and E2 nested outer with 680 bp amplicon and inner resulting in 270 bp amplicon. The E2 inner nested RT - PCR amplified products were bulk produced, purified and sequenced and nucleotide blast analysis performed. Phylogenetic analysis of the sequenced isolate was compared with few available genebank sequences, revealed maximum 96% homology with CSFV Hisar polyprotein gene and 95% with CSFV Kerala isolates. Based on the phylogenetic analysis, the Erode isolate was grouped closer to the Kerala isolate tracing back the spread of the disease may be from the neighbouring state Kerala. Further, virus isolation was done in PK15 cell line and after 4 dpi confirmed by indirect immunofluorescent test using standard polyclonal serum showed intracytoplasmic fluorescence in the infected cells.