ISOLATION AND PROPERTIES OF 2 NEW RNA PHAGES SP AND FI

New RNA phages were isolated from feces of Siamang Gibbon and infants, and their characters were investigated. These phages, SP and FI were serologically unrelated to any of known RNA phages (group I, II and III) and were classified into groups IV and V. Several other characters, such as filtration and elution patterns through membrane filters, buoyant densities in CsCl, and UV sensitivities of SP and FI were similar to those of the group III phages, suggesting that a certain similarity between group III and IV or V might exist. Peculiar phage‐host relations found in phages of FI group were also discussed. From these results, we propose new possible schemata for the grouping of RNA phages. © jointly owned by Japanese society for Bacteriology and Society of Japanese Virologists