Isolation and Identification of Viruses from Adult Largemouth Bass during a 1997–1998 Survey in the Southeastern United States

Abstract

A total of 452 largemouth bass Micropterus salmoides (mostly adults) from 78 reservoirs, lakes, rivers, and state fish hatcheries in eight states of the southeastern USA were surveyed for largemouth bass virus (LMBV) between August 1997 and November 1998. Virus was isolated from ostensibly healthy electrofished largemouth bass from six reservoirs on four different river systems—Lakes Jordan (Coosa River) and Wilson (Tennessee River) in Alabama; Lakes Walter F. George and Oliver (Chattahoochee River), Lake Blackshear (Flint River), and Lake Allatoona (Coosa River) in Georgia—and from moribund fish from Lake Walter F. George and Lake Greenwood (Santee River) in South Carolina. Fish samples from 71 locations in Alabama, Florida, Georgia, Kentucky, Louisiana, Missouri, South Carolina and Virginia showed no evidence of virus infection. Sequence analysis of the major capsid protein gene showed that virus isolates from Lakes Walter F. George, Jordan, Blackshear, and Allatoona were identical to the original LMBV isolate from Santee–Cooper Reservoir. Largemouth bass virus is a member of the genus Ranavirus within the family Iridoviridae and is nearly identical to doctor fish virus (DFV-16) and guppy virus (GV6), two fish viruses from Southeast Asia.