A simple and efficient method to rescue very virulent infectious bursal disease virus using SPF chickens

Abstract

Reverse genetic systems for efficient generation of very virulent infectious bursal disease virus (vvIBDV) are currently limited. In this study, we have developed a simple and efficient way to rescue vvIBDV using SPF chickens. The genome of a vvIBDV strain, HLJ0504, flanked by hammerhead and hepatitis delta ribozyme sequences, was cloned downstream of the cytomegalovirus enhancer and the chicken beta-actin promoter of the vector pCAGGS. After transfection of DF-1 cells, cell suspensions were injected into the bursa organ of three-week-old SPF chickens. Using this system, vvIBDV was recovered at high titers after one passage, and the rescued vvIBDV remained highly lethal to SPF chickens. This simple and efficient method to rescue vvIBDV will be a valuable tool for better understanding the molecular virulence determinants of vvIBDV.