title: Characterization of a new strain of Taura syndrome virus (TSV) from Colombian shrimp farms and the implication in the selection of TSV resistant lines.
abstract: Prior to 2004, Colombian shrimp farming benefited from a selection program in which Penaeus vannamei stocks were developed with resistance to Taura syndrome disease (TS). However since 2004, TS reappeared as a significant disease. In 2010, an apparently new strain of TSV (designated as CO 10) was collected in Colombia. Its genome was sequenced and compared with six other fully sequenced isolates. This analysis revealed that the TSV CO 10 is closely related to the isolates from Hawaii and Venezuela. Phylogenetic analysis based on capsid protein 2 (CP2) region from 59 TSV isolates shows that the recent Colombian isolates (2006-2010) form a new cluster and differ from the previous Colombia isolates (1994-1998) by 4% in nucleotide sequence. The virulence of this CO 10 isolate was similar to a Belize TSV determined through experimental infection in P. vannamei showing 100% mortalities and similar survival curves. By RT-qPCR for TSV, the viral loads were also close in the infected shrimp from both CO 10 and Belize at the order of 1×10(10) copies per μl RNA. To develop TSV-resistant lines, the candidate shrimp should be challenged with virus strains that have been isolated most recently from the regions where they will be cultured. This study suggests that the TSV present in Colombian shrimp farms during the last 5 years is a new TSV strain with high virulence.
authors.affiliation: The University of Arizona, Aquaculture Pathology Laboratory, Dept. Veterinary Science and Microbiology, 1117 E. Lowell St., Tucson, AZ 85719, USA. lfarangu@email.arizona.edu
authors.forename: Luis Fernando
authors.initials: LF
authors.lastname: Aranguren
authors.forename: Marcela
authors.initials: M
authors.lastname: Salazar
authors.forename: Kathy
authors.initials: K
authors.lastname: Tang
authors.forename: Xenia
authors.initials: X
authors.lastname: Caraballo
authors.forename: Donald
authors.initials: D
authors.lastname: Lightner
mesh_terms: D000818:Animals; D017756:Aquaculture; D001483:Base Sequence; D003105:Colombia; D056629:Dicistroviridae / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D008969:Molecular Sequence Data; D033561:Penaeidae / Q000821:virology*; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019562:Viral Load; D014774:Virulence