Abstract: | The interaction of S. flexneri converting phages PE5, P90 and fV with E. coli antigenic variant O129, E. coli O129 converting phage VB with the above antigenic variant and with S. flexneri y-variant was studied. Phage PE5 and phage VB were found to induce the conversion of O-antigen in E. coli antigenic variant 0129 and in S. flexneri y-variant with the detection of antigens V and 7,8. Phages P90 and fV induced no conversion of O-antigen. Changes in the antigenic properties of convertants were confirmed by the results obtained in the agglutination test and in the agglutination adsorption test. |