[Change of serological properties of museum strains of Shigella flexneri in different terms of storage].

The viability, purity, biological and serological properties of museum strains of Shigella flexneri which were kept in lyophilized state during above 30 years were studied. Primary serological characteristics were specified, it was established that type 2a is the predominant serotype independent of the years and regions of isolation. Some strains lost antigens as a result of the long-term preservation or reinoculation on agar media.