Typing of Shigella sonnei colicins by means of specific indicators

An enlarged and perfected scheme of typing of Shigella sonnei colicins is based on the knowledge of types of colicins produced by Abbott's types as well as by newly discovered and determined colicin types. A set of specific indicators prepared from E. coli K13 HfrR, E. coli C6 and Shigella sonnei by a selection of suitable mutants and recombinations was used for the typing. Seven new colicin types were determined on typing shigellae found in the field. Type 9A produces colicins E3, Ia, Type 16 produces colicin B, Type 17 colicins B, Ib, Type 18 colicins E2+?, Type 19 colicins E2, Ia, Type 20 colicins E1, Ib, Type 21 colicins E2, ib. The present scheme can be enlarged, when new types are found.