Characterization and risk assessment of a novel virus isolated from white sucker fish (Catostomus Commersonii) in Wisconsin

Abstract

White suckers are important both ecologically and economically as baitfish. Wild white suckers and baitfish suckers are affected by viral diseases. In 2010, the La Crosse Fish Health Center (LFHC) isolated a novel virus from white suckers being sold as baitfish in Wisconsin. Since then, the LFHC has presumptively detected this virus in wild white suckers and in white suckers being sold as baitfish, but has not had a definitive assay. Previous research generated genomic information and that suggested the virus belonged to the family Bunyaviridae. The virus was named white sucker bunyavirus (WSBV). Further sequence analysis confirmed that this virus was a bunyavirus, but was distantly related to all known bunyaviruses. This sequence information was used to develop a diagnostic RT-PCR assay for WSBV. The assay was used to detect WSBV during a preliminary survey and experimental infection. In the survey, no fish from the twelve watersheds surveyed tested positive for WSBV. The assay has since been used to identify WSBV from 11 previous presumptive isolations collected by the LFHC. The experimental infection demonstrated WSBV was pathogenic to juvenile white suckers at high doses (107 PFU). Environmental agencies should now consider WSBV significant viral agent of white sucker fish.