title: Characterization of a Taura syndrome virus isolate originating from the 2004 Texas epizootic in cultured shrimp.
abstract: A comprehensive investigation of the Taura syndrome virus (TSV) isolate that caused epizootics in shrimp farms in Texas in 2004 (Texas isolate) revealed that this virus was more virulent in laboratory bioassays than the TSV reference isolate, Hawaii 1994, causing severe symptom development and rapid mortality. Histopathology of moribund animals demonstrated epithelial necrosis within the stomach, appendages, general body cuticle and gills, and the surviving animals demonstrated moderate to numerous lymphoid organ spheroids. Purified virions showed icosahedral morphology, with a diameter of 31 nm. Comparative genome analysis showed that the Texas isolate is more closely related to TSV isolates from Thailand and China than to the Hawaii isolate. The predicted tertiary structures of the inhibition of apoptosis protein (IAP) and protease domains of the Texas isolate are very similar to those of the Hawaii isolate. However, the RNA-dependent RNA polymerase (RdRp) of the Texas isolate has significant structural differences from the Hawaii isolate due to point mutation(s) in the RdRp gene. Changes in the RdRp tertiary structure might contribute to the replication fidelity, virulence and ecological adaptability of the Texas isolate.
authors.affiliation: Advanced BioNutrition Corporation, Columbia, MD 21046, USA. ADhar@abn-corp.com
authors.forename: Arun K
authors.initials: AK
authors.lastname: Dhar
authors.forename: Dilip K
authors.initials: DK
authors.lastname: Lakshman
authors.forename: Keenan
authors.initials: K
authors.lastname: Amundsen
authors.forename: Refugio
authors.initials: R
authors.lastname: Robles-Sikisaka
authors.forename: Krista N
authors.initials: KN
authors.lastname: Kaizer
authors.forename: Sribash
authors.initials: S
authors.lastname: Roy
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Hasson
authors.forename: F C Thomas
authors.initials: FC
authors.lastname: Allnutt
mesh_terms: D000818:Animals; D016000:Cluster Analysis; D056629:Dicistroviridae / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity* / Q000648:ultrastructure; D005880:Gills / Q000473:pathology; D008969:Molecular Sequence Data; D033561:Penaeidae / Q000821:virology*; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D012327:RNA Virus Infections / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D013270:Stomach / Q000473:pathology; D013781:Texas; D014764:Viral Proteins / Q000737:chemistry; D014771:Virion / Q000648:ultrastructure; D014774:Virulence
chemical_list: D012367:RNA, Viral; D014764:Viral Proteins