[Study of the virulence of Shigella sonnei isolated from persons with different forms of dysenteric infection].

Possible ranges of virulence of Sh. sonnei strains isolated from the patients and carriers in the foci of Sonne dysentery, supposedly with the same source of infection, were studied. Sh. sonnei strains isolated from carriers proved to be less virulent than the strains isolated from patients with the clinical manifestation of the infection. A hypothesis was put forward explaining some aspects of carrier state in Sonne dysentery, which most probably was explained by the refracterity of the macroorganism, not by the alterations in the genom of the causative agent.