Abstract: | The study of the interaction between mutants of Sh. flexneri 2a and epithelial HeLa cells has revealed that in all cases the loss of virulence in the studied groups of mutants, resistant to antibiotics with different mechanisms of action (polymyxin M, mecillinam and neamin) was linked with the loss of the ability of bacteria to penetrate into epithelial cells. These changes are probably the result of disturbances in the structure of external membrane in polymyxin-resistant mutants, in the regulation of the penetration factor synthesis in mecillinam-resistant mutants, and in the translation process in neamin-resistant mutants. |