[Phenomenology and molecular mechanisms of Shigella sonnei dissociation: its variability in model in vivo and in vitro systems]. / Fenomenologiia i molekuliarnye mekhanizmy dissotsiatsii Shigella sonnei: izmenchivost' v model'nykh sistemakh in vivo i in vitro.

The dynamics of the accumulation of phase II S. sonnei in the infectious process in germ-free rats, during cultivation and in subcultures was studied. The in vivo variability of S. sonnei showed a sharply defined phasic character of the process with the periods of the apparent absence of phase II, the increase of its occurrence and stabilization with the preservation of S-forms in minor amounts. Kanamycin-resistant phase II accumulated in vivo more rapidly than in vitro. Cultivation with sodium desoxycholate was found to accelerate the process of disassociation. The characteristic feature of all dissociants detected in all systems was their plasmid profile: in phase I, plasmids of 120 and 60 Md, as well as small plasmids, were detected; in phase II disassociants, plasmid with a molecular weight of 120 Md was absent. The restriction analysis of total plasmid DNA by means of restrictase EcoR1 showed the absence of 3 fragments in phase II while other 13 fragments were retained. These results open prospects for the molecular cloning of the gene antigen of phase II.

[Cell wall composition of Streptomyces roseoflavus var. roseofungini and its Nocardia-like variant]. / Sostav kletochnykh stenok Streptomyces roseoflavus var. roseofungini i ego nokardiopodobnogo varianta.

The composition of cell walls was comparatively studied in Streptomyces roseoflavus var. roseofungini 1128 and in its variant 1-68. In the logarithmic phase of growth, the content of teichoic acid in the cell wall of the parent culture was four times as high as in the cell wall of the variant. The cell walls of the parent culture contained 5 to 7 times more O-lysyl residues not only due to a higher content of teichoic acid in the walls but also owing to a lower content of lysyl groups in the teichoic acid of the variant. An additional polysaccharide comprising galactose and glucosamine was found in the cell wall of the variant but not in the parent strain. The peptidoglycan of the both cultures had a structure typical of Streptomyces spp.; its content in the cell walls of the two cultures was identical (ca. 50% of the dry cell wall biomass weight). The results are discussed in connection with the peculiarities of the variant hyphal septation.

[Structure of cell-wall teichoic acids in Streptomyces roseoflavus var. roseofungini and its Nocardia-like variant]. / O strukture teikhoevykh kislot kletochnykh stenok Streptomyces roseoflavus var. roseofungini i ego nokardiopodobnogo varianta.

The structure of teichoic acids was studied in the cell walls of Streptomyces roseoflavus var. roseofungini 1128 and its Nocardia-like variant 1-68 differing from the parent strain in the absence of a spore-forming aerial mycelium as well as by the fragmentation of hyphae in the substrate mycelium. The teichoic acids of the both cultures consist of a 1,3-poly(glycerophosphate) chain containing 11-13 glycerolphosphate residues which have glucosamynl units and lysine groups bound through an ester bond. These teichoic acids contain no O-acetyl groups, in contrast to the glyceroteichoic acids of actinomycetes studied earlier. The teichoic acid from the cell wall of the variant has less lysine and glucosamine then the parent strain. The content of teichoic acid in the cell wall of the parent culture is 4.5 times greater than in the wall of the variant.