[Immunoenzyme test system for detecting antibodies to group-specific antigens of group A Streptococcus on the base of conjugated N-acetylglucosamine and its use in medical practice].

Enzyme immunoassay kit has been created for detecting antibodies to group A Streptococcus, based on N-acetylglucosamine. N-acetylglucosamine was selected as the group-specific determinant due to the structure of group A Streptococcus polysaccharide, in which this monosaccharide residue is lateral to the main polysaccharide chain and hence more available for antibodies. Water-soluble polyacrylamide is the carrier in this kit, for this carrier is stable and not liable to nonspecific reaction with proteins.

[The production of erythrogenic toxin and the epidemic process in respiratory streptococcal infection].

The capacity of Streptococcus pyogenes, isolated from clinically healthy children in a large organized group, for producing erythrogenic toxin A, B and C was studied. The dynamics of toxin production was compared with changes in the levels of morbidity and carrier state, as well as with some characteristics of the interaction between the populations of the infective agent and the host by such values as virulence and susceptibility. Similarity in the dynamics of the parameters under study was noted.

[The M-protein heterogeneity of Streptococcus pyogenes strains isolated from clinically healthy and ill children in an organized collective].

The study of the kinetic curves of the lysis of group A S. pyogenes cell-walls (cells), serovars 29 and 12 M, variants M+ and M-; with endo-N-acetyl-muramidase revealed that the kinetics of the lysis of virulent and avirulent strains was different: variant M- was lyzed faster than M+. This difference in the cell-wall lysis of both variants made it possible to use this method for the identification of M+ and M- states of the strains.

[The heterogeneity of Streptococcus pyogenes strains isolated from clinically healthy and sick children in an organized collective].

Experiments on typed strains used as an example revealed that kinetic curves obtained in the lysis by endo-N-aretylmuramidase of virulent strains greatly differed from those obtained from nonvirulent ones: the lysis rate of M+ variants was less than that of M- variants; M- strains gave rather steep kinetic curves of lysis, while those of M+ strains were more declivous. In this study group A S. pyogenes cultures isolated from healthy and sick children in a summer camp were used.

[Streptococcal group A carriage: new data on the characteristics of the biology of the causative agent and of the immune response of the host].

Carriership of group A streptococcus (A-STR) was registered with significantly greater frequency among children of preschool and early school age (29.8%) than among adults (4.0%).

[An explosive outbreak of strep throat morbidity in an adult organized collective].

Altogether 162 cases of tonsillitis were registered in two military units during the period of May 11-16. The disease took an acute course with short-time fever, symptoms of acute intoxication, sore throat, pronounced inflammatory changes in tonsils and swelling of regional (submaxillary and anterocervical) lymph nodes. In some of the patients (1.

[The modification of the cell wall proteins in group A streptococci type M 29 under the influence of spermidine contained in the culture medium].

The addition of spermidine into growth medium used for the cultivation of group A streptococci, type M 29, leads to changes in the amino acid composition of cell walls and surface proteins isolated by the method of E. H. Beachey et al.

[The low-molecular protein of the cell wall in streptococci group A devoid of serological type specificity].

The scheme for the isolation and purification of low-molecular cell-wall protein without type specificity, including the extraction of the cell walls of group A streptococci, type M 29, with 1% solution of Triton X-100, the separation of the extract by ion-exchange chromatography in DEAE-trisacryl M with the subsequent two-stage gel filtration in superfine Sephadex G-50, is described. The isolated protein had a molecular weight of 4,000 daltons and contained no admixtures of group-specific polysaccharide A, phosphorus, nucleic acids and Fc receptors and interacted with antisera to group A streptococcal cells of heterologous type M in the enzyme immunoassay (EIA). Purified protein was characterized by a high content of glycine.

[The pharyngeal beta-hemolytic streptococcal carrier state among blood donors].

459 blood donors aged 18-50 years were examined in 1987-1988 in Moscow. Among them, carrier state with respect to beta-hemolytic streptococci was detected in 107 donors (23.3%).

[A study of the variability of group A type M29 streptococcus on exposure to biologically active substances].

Biologically active substances spermidine and the compounds contained in the low-molecular fraction of cattle blood serum change the phenotype of type 29 group A Streptococcus. Amino acid analysis and enzymatic destruction of cell walls have demonstrated changes of the streptococcal biological characteristics and cell wall structural organization. These changes may result from loss of supervariable component of the M-protein when compounds from cattle blood serum low-molecular fraction are added to culture medium and by unbalanced growth of Streptococcus after spermidine addition to growth medium.

[Heterogeneity of streptococcus group A cell wall protein components].

Cell wall surface proteins of group A streptococcus (M 29) were isolated by mild chemical extraction with 1 M hydroxylamine pH 6.0 (37 degrees C). The proteins were purified by ammonium sulfate fractionation, gel filtration on Sephadex G-150 and ion-exchange chromatography on DEAE-Trisacryl M.

[The physicochemical and biochemical characteristics of the cell walls in M+ and M- variants of Streptococcus group A type 29].

The amino acid composition of cell walls and surface proteins, isolated from virulent (M+) and avirulent (M-) streptococcal strains (group A, type 29) has been determined by the method of E. H. Beachey et al.

[The epidemic process of an acute streptococcal respiratory infection in large organized collectives of children].

The study of the specific features of the development of the epidemic process of scarlet fever, tonsillitis, and acute respiratory diseases (ARD) in two large organized groups of children revealed the presence of some differences which depended on the character of prophylactic measures taken in these groups. Thus, in the absence of prophylaxis with bicillin a pronounced increase in the level of carriership, accompanied by an increase in the infective capacity of carriers, was noted. This resulted in a high level and unfavorable dynamics of morbidity in scarlet fever, tonsillitis, and ARD.

[Study of the composition of cell wall of group A Streptococcus after hydrolysis using muramidase from Streptomyces levoris].

The aim of the experiment was to study the lysis products of cell walls of group A streptococci resulting from exposure to N-acetylmuramidase. It was shown that for isolating surface proteins free of polysaccharide and peptidoglycan fragments it was necessary to treat the streptococcal cell walls with endo-beta-N-acetylmuramidase for no more than 30 minutes. Prolonged hydrolysis with muramidase led to the presence of polysaccharide and the peptidoglycan fragments in the protein fractions, intracellular wall proteins covalently bound to the peptidoglycan fragments and polysaccharide being also released.

[The effect of blood serum components on the growth, biochemical and biological properties of streptococcus].

The components of cattle blood serum, added to the medium for the cultivation of group A streptococci, considerably decrease the period of adaptation and increase the balanced growth rate of streptococci, which is manifested by changes in the surface structures of the cell wall: the absence or modification of protein M. Streptococci grown under these conditions lose their capacity for phagocytosis, and from the cell walls obtained from these streptococci no surface protein M can be isolated by pepsin treatment. Nevertheless, the ratio of the main cell-wall components (proteins, polysaccharide and peptidoglycan), the amino acid composition, as well as the resistance of the cell walls to the action of trypsin and endo-N-acetylmuramidase are the same in M+ and Mx variants, that makes it possible to infer that the modification of protein M or the inhibition of its synthesis occurs during the growth of streptococci in the presence of blood serum components.

[Hydrophobic quality and the level of surface proteins in the cell wall of cultures of Streptococcus pyogenes isolated from clinically healthy children from an organized collective].

The Str. pyogenes cultures isolated from clinically healthy children were found to have different hydrophobic properties and quantities of surface cell wall proteins, and to exhibit pronounced variability in these signs in time. Most studied cultures lacked a correlation between their hydrophobic properties and the quantity of surface proteins of the cell wall.

[Changes in the cell wall composition and structure of Streptococcus pyogenes during batch culture].

Changes in S. pyogenes cells in the process of batch cultivation have been studied. The composition of S.

[Ribosomes of the blue-green alga Anabaena variabilis. Sedimentation, density characteristics and analysis of ribosomal RNA].

Ribosomes and rRNAs were isolated from cells of green-blue alga Anabaena variabilis. The sedimentation properties of the ribosomes as well as density, molecular weights and nucleotide composition of rRNAs were determined. The ribosomes were found to have the S20,w value equal to 67.