[Experimental study, using a pulmonary model, of the pathogenic properties of genetically related strains of Sh. flexneri, differing in their ability to cause keratoconjunctivitis].

Complex microbiological and morphological study of the genetically connected Sh. flexneri strains, avirulent by keratoconjunctival test showed that the greatest extent of the virulent loss was revealed in shigellae with mutation in the area glpK-gene: they lost the capacity to penetrate into the cells of the bronchial epithelium, to resist local leukocytic reaction and to produce an injurious action on the pulmonary vessels. Shigellae with the replaced kcpA- gene area mostly lost the capacity to penetrate into the epithelial cells of mouse bronchi and were eliminated from the epithelium by the 9th hour after the administration. Xyl--avir-hybrids obtained from crossing of Sh flexneri with the streptomycin-resistant E. coli K12 donors were characterized by the loss of the capacity to prolonged reproduction in the organism of mice with the retention of the capacity to penetration into the epithelium, of the influence on the development of the leukocytic reaction and of the damaging effect on the pulmonary capillaries.