ANTIGENIC CHANGES IN SHIGELLA FLEXNERI GROUP BY BACTERIOPHAGE

Abstract

Using a frozen-thawed filtrate prepared from a strain of Sh. flexneri (EW 19), the occurrence of antigenic change I to IV as well as III to IV has been observed experimentally.
The antigen changing factor was considered to be the temperate phage possessed by Sh. flexneri 4c (EW 19).
The antigenically changed strains had biological properties similar to their parent strains. There were no indications that the biological characteristics of the strains from which the filtrate was prepared were introduced into the antigenically changed strains.