[The clinico-pathogenetic significance of the outer membrane proteins determined by the invasiveness plasmid in Flexner's shigellosis].

S. flexneri 2a outer membrane proteins of 38, 43, 62 and 78 kD, determined by the 140 mD invasiveness plasmid, serving as antigens and specific rabbit sera serving as antibodies were used for diagnosing S. flexneri infection in the enzyme immunoassay. The examination of 96 patients and 20 healthy donors showed the possibility of the detection of S. flexneri 2a protein invasins and antibodies to them at different periods of the disease. During the severe course of shigellosis a higher level of protein invasins in the blood serum of patients was established in comparison with that observed during the medium severe course. An elevated level of protein invasins in the blood serum was accompanied by a lower content of specific antibodies to them, which was probably due to the immunosuppressive action of the invasiveness plasmid, established in earlier experiments.