[Genetic characteristics and trends in the spread of a new Shigella flexneri subserovar with the antigenic formula IV:7,8]. / Geneticheskaia kharakteristika i tendentsii v rasprostranenii novogo podserovara Shigella flexneri s antigennoi formuloi IV:7,8.

As the result of experiments with the conjugation of S. flexneri strains 4 belonging to an unusual subserovar (IV: 7,8) with Escherichia coli donor strains K12 Hfr C and Hfr H, as well as experiments with converting phages IV and 7,8, this new subserovar of S. flexneri 4, similarly to other S. flexneri subserovars, was proved to be the Y-variant of shigellae rendered lysogenic by the two above phages. The experiments also revealed that 97.9% of all S. flexneri strains 4 (IV: 7,8) under study possessed invasive properties and were capable of inducing specific keratoconjunctivitis in guinea pigs. Observations on the isolation of S. flexneri strains 4 belonging to the new serovar (IV: 7,8), carried out by the All-Union Shigelloses Center on its basal territories in 1980-1984, made it possible to establish the tendency towards a wider circulation of this infective agent in the USSR.

[Biochemical properties of Shigella flexneri and their practical significance]. / Biokhimicheskie svoistva Shigella flexneri i ikh prakticheskoe znachenie.

As the result of the study of 921 S. flexneri strains 1-6 and 4 (IV: 7,8), isolated in 31 regions of the USSR in 1975-1984, their biochemical characterization by 33 tests was made. All the strains under study proved to be typical in most of their constant signs, only some of strains 2a showed deviations in mannitol and some of strains 4a, in acetate. In strains of serovar 6, circulating in the USSR, specific features with respect to dulcitol and xylose were noted. The possibility of the biochemical subserovar typing of S. flexneri 1-5, X- and Y-var., with respect to maltose, arabinose, sorbitol and rhamnose was confirmed.

[Structure of the causative agents of shigellosis in areas of the USSR 1979-1981]. / Struktura vozbuditelei shigellezov na nekotorykh territoriiakh SSSR v 1979-1981 gg.

Summarized data on the specific structure of Shigella strains isolated in different territories of the USSR in 1979-1981 are presented. These data indicate that in the intra-specific structure of S. flexneri strains the proportion of serological subvariant 2a increased and that of serological variant 6 and subvariants 16 and 4a decreased during this period. Using one of the base territories of the All-Union Shigellosis Center as an example, the spread of an unusual serological variant of S. flexneri (IV:7,8) in the USSR is shown. The increase of the proportion of S. boydii strains, mainly S. boydii 4, is noted.

[Unusual serovar of the causative agent of Flexner's dysentery. I. Its distribution and biochemical properties]. / Neobychnyi serovar vozbuditelia dizenterii Fleksnera. Soobshchenie I. Rasprostranenie i biokhimicheskie svoistva.

The data on the circulation of some S. flexneri strains in the USSR are presented. The antigenic structure of these strains (type antigen 4 and group antigens 7, 8) is not characteristic of known serological subvariants 4a, 4b or var. X. The time course of changes in their spreading on certain base territories controlled by the All-Union Shigellosis Center in 1980-1983 is shown. The biochemical characteristics of S. flexneri strains IV:7,8 under study, isolated in the USSR and abroad (Czechoslovakia, London) from humans, from a monkey and from the environment, are given. Similarities in the biochemical reactions of these strains with respect to indole, rhamnose, saccharose, maltose, arabinose and raffinose have been revealed. The strains isolated in the USSR have shown differences in the spectra of their resistance to antibiotics, depending on their territorial origin.