BIOLOGICAL AND PHYSICOCHEMICAL PROPERTIES OF THE IRIDOVIRUS ISOLATED FROM CULTURED RED-SEA BREAM, PAGRUS-MAJOR

Eleven fish cell lines were compared for susceptibility to red sea bre am iridovirus (RSIV). Cytopathic effect was produced in BF-2, CHSE-214 , FHM, JSKG, KRE-3, RTG-2 and YTF cell lines among the cell lines exam ined. The titers of the virus on BF-2 and KRE-3 were higher than those on the other cell lines. The pretreatment of BF-2 and KRE-3 cells wit h polyethylene glycol (PEG) or addition of PEG to the sample increased the virus titers. RSIV replicated at 15-degrees-C, 20-degrees-C, 25-d egrees-C and 30-degrees-C but not at 37-degrees-C. The suitable temper ature for viral growth was 20-degrees-C or 25-degrees-C. The virus was sensitive to acid (pH 3), chloroform and ether and unstable to heat b ut stable to ultrasonic treatment and repeated freezing and thawing. T reatment with 5-iodo-2-deoxyuridine (IUdR) reduced the titers of the v irus.