Pathological and Molecular Study of Taura Syndrome Virus (TSV) in Shrimp Litopenaeus vannamei in Iran

In 2007, mass mortality occurred in juvenile shrimp L. vannamei in most farms of Bousher province in the south of Iran. The gross sign of moribund shrimp was red discoloration in body surface as well as in tail and appendage. The gut of shrimp was empty and by close observation many necrotic area were seen in the tail and appendage. 200 samples collected and fixed in Davidson fixative for histopathology. The small part of pelopoda was preserved in ethyl alcohol 95% for polymerase chain reaction. The histopathological finding that characterize in acute form of TSV were multifocal necrosis in the cuticular epithelium and often, the subcuticular connective tissue and at time, the underlying striated muscles, multiple, spheroid inclusion body were scattered the affected area of cuticle tissue. This spherical inclusion body in H&E/Ph staining showed eosinophilic to basophilic color in hind gut and stomach. The samples also examined by PCR KIT for TSV infection by IQ 2000TM WIT Multivir System and IQ 200 TM TSV Detection and Prevention Kit (Farming IntelliGene Technology Corporation, Taipei, Taiwan) with the respective RNA extracts. The PCR results showed positive reaction to infection with TSV.