Lysogeny and lysosensitivity in Shigella dysenteriae group of bacteria - I. Isolation of bacteriophages and receptor substances

The set of lysogenic phages D2/D7, D4/D7, D5/D7, D8/D7, D4/B15 and D8/B15 was prepared from lysogenic bacterial strains representing various serotypes of Sh. dysenteriae. The activity spectrum of these phages was limited to some serotypes of Sh. dysenteriae, Sh. boydii, and to Sh. sonnei; they were not active against Sh. flexneri. With the use of a prepared set of phages, the Sh. dysenteriae 7 (D7) strain was found to be a strain with a broad spectrum of phage sensitivity, which was sensitive to all prepared temperate phages, and also to T2, T3, T4 and T6 phages. Extracts from D7 strain were shown to contain the receptor activity for prepared temperate phages as well as for T phages; trichloracetic acid extract (TCA) contains receptors for temperate phages. Receptor activity for phages T2 was found in water extract (H₂O 65‡C) as well as in TCA and water/phenol extracts (Aq/Ph 65‡C), while receptor activity for phage T4 was found only in Aq/Ph 65‡C. This extract has also shown some activity against phages T3 and T6. The results suggest that the receptor sites for T-phages in the Sh. dysenteriae 7 may be differently localized than in the E. coli B. The receptor sites for the temperate and for T-phages were shown to differ.