Molecular Detection of Aquatic Birnaviruses from Marine Fish and Shellfish

Abstract

Birnaviruses have been isolated from several kinds of marine fin fish (Kusuda et al., 1993) and shellfish (Rivas et al., 1993). The isolates are distinguishable from infectious pancreatic necrosis virus (IPNV) in terms of antigenicity and genogrouping by using VP2NS junction region (Hosono et al., 1996). Hosono et al., 1996 proposed the tentative term, marine birnavirus (MABV), which includes yellowtail ascites virus (YAV) (Sorimachi & Hara, 1985), viral deformity virus (VDV) (Nakajima et al., 1993) and other birnaviruses isolated from marine fishes (Kusuda et al., 1989; Kusuda et al., 1994). A molecular detection technique was needed to determine the distribution of MABV and to determine the variation in the viral genome from different MABV isolates. This information is important in understanding the spread of MABV between susceptible hosts and reservoirs of infection in natural environment. We recently developed a 2-step PCR method specific for birnaviruses (Suzuki et al., 1997). In this paper, the MABV genome was surveyed by using the 2-step PCR on fish and shellfish samples.