Chinese sacbrood virus infection in Apis mellifera, Shandong, China, 2016

The Chinese sacbrood virus (CSBV) was first isolated from Apis cerana in 1972. However, the biological characteristics of the CSBV that naturally infects Apis mellifera, causing larval death, have not been reported yet. In the present study, natural CSBV infection was evaluated using clinical symptoms of A. mellifera larvae, RT-PCR, electron microscopy, agar gel immunodiffusion assays, and virus analysis in inoculated A. cerana larvae. The isolated CSBV strain was named AmCSBV-SDLY-2016. Subsequently, AmCSBV-SDLY-2016 was analyzed by constructing a phylogenetic tree using VP1. Data from the phylogenetic tree suggested that AmCSBV-SDLY-2016 is evolutionarily close to JLCBS-2014. It was also observed that CSBV crossed the species barrier, causing the death of A. mellifera larvae.