Fifty-four Shigella sonnei colicin types and their typing by specific indicator strains.

Fifty-four S. sonnei colicin types and 92 indicator strains used for their determination are listed. Most of the indicators were prepared by conjugational transfer of Col factors from shigellae to the recipient strains of E. coli K13 HfrR nalr and E. coli K12 ROW or by selection of resistant mutants of these strains or by combination of both methods. Ten indicators are S. sonnei strains. The indicator strains are suitable for E. coli colicin typing.