Establishment of a RT-PCR Assay for the BLSV Gene and the Molecular Detection of BLS

Based on the reported Big liver and spleen disease virus (BLSV) gene sequence, a pair of primers was designed and a 375bp product was amplified from the total RNA extracted from homogenates of BLSV-infected livers. Twenty liver samples were randomly collected from two commercial broiler breeder flocks in Nanjing.One of ten liver samples was positive reaction in RT-PCR in one flock but not in another. The RT-PCR detection for cDNA from BLSV was specific with the sensitivity of 4.16×10~(-3)μg/μL. Phylogentic tree analysis suggested that the 338bp sequence of the isolated strain (BLSV-NJ2002) shared 97.3% and 83.6% nt hemologue indentities with that of Australia strain and avian HEV respectively.