[alpha-Hemolysin of E. coli]. / al'fa-Gemolizin E. coli

The activity of alpha-hemolysin increased at the log growth phase in the culture of E. coli P678 Hly+ hemolytic strain; this activity diminished with the change into the stationary phase, and then fell sharply. Replacement of the culture medium in the stationary growth phase by fresh one led to restoration of the hemolytic activity of the culture. The culture fluid separated from the cells at the stationary growth phase produced an inhibitory action on the alpha-hemolysin Ca ions activated and stabilized the alpha-hemolysin. Sodium citrate and sucrose served as hemolysis inhibitors. The action of alpha-hemolysin was maximal against human erythrocytes at pH 6.5. Hemolytic activity was characterized in time by a distinct lag-phase and the phase of the greatest rate of reaction. The duration of the lag-phase and also the rate of hemolysis depended on the concentration of alpha-hemolysin (with the increase of the hemolysin concentration lag-phase was shortened and the reaction was accelerated). There proved to be a linear relationship between the amount of erythrocytes taken into the reaction and the rate of hemoglobin release, and also there was noted a temperature activation of the hemolytic reaction.

[Some properties of the alpha-hemolysin produced by a hemolytic strain of E. coli]. / Nekotorye svoistva al'fa-gemolizina, produtsiruemogo gemoliticheskim shtammom E. coli

It was found that alpha-hemolysin of E. coli P 678 HIy+ was maximally active against human erythrocytes at pH 6.5. The hemolytic activity is characterized in time by a distinct lag-phase and a phase of the greatest velocity of the reaction immediately following it. The duration of the lag-phase and also the rate of hemolysis depends on alpha-hemolysin concentration, whose increase is accompanied by a decrease of the lag-phase and acceleration of hemolysis. There is a definite limit below which the duration of the lag-phase remains unchanged with further increase of hemolysin concentration. There was noted a linear relationship between the amount of erythrocytes taken for the test and the rate of hemoglobin release and also a temperature activation of the hemolytic reaction.

[Immunochemical analysis and protective properties of components of Pseudomonas aeruginosa mucus with different molecular weights]. / Immunokhimicheskaia analiz i protektivnye svoistva komponentov slizi Pseudomonas aeruginosa s raznoi molekuliarnoi massoi.

P. aeruginosa slime has been separated into fractions XM-300 (3 X 10(5) daltons and more), XM-100 (1 X 10(5) = 3 X 10(5) daltons), PM-30 (3 X 10(4) = 1 X 10(5) daltons) and PM-10, (1 X 10(4) = 3 X 10(4) daltons) by ultrafiltration. The high-molecular slime components (3 X 10(4) daltons and more) have been found to be serologically more active than the low-molecular components (1 X 10(4) = 3 X 10(4) daltons). As shown in experiments on mice, both high-molecular toxic and low-molecular nontoxic slime components have protective activity, but the high-molecular components are more active than the low-molecular ones. The slime components stimulate the formation of immunity to homologous and partially heterologous P. aeruginosa strains in mice. Antigenic relationship between the slime components (especially the high-molecular ones) and the corresponding lipopolysaccharides has been noted.

[Immunological study of cellular components of Pseudomonas aeruginosa. IV. Fractionation of Pseudomonas aeruginosa mucus by diafiltration and biological properties of isolated fractions]. / Immunologicheskoe izuchenie kletochnykh komponentov sinegnoioni palochki. Soobshchenie IV. Fraktsionirovanie slizi Pseudomonas aeruginosa metodom diafil'tratsii i biologicheskie svoistva vydelennykh fraktsii.

In fractionation of Pseudomonas aeruginosa mucus (strains No. 8 and 1463) by means of diafiltration on the system of membranes Diaflo XM-300, XM-100A, PM-30, and PM-10 there was obtained a successive series of fractions differing by the molecular weight and chemical composition. According to the results of gel chromatography fractions with the mol wt of 100000 dalton and over apparently represented protein-polysaccharide components of mucus in the form of complexes; fractions with the mol wt of 30000 dalton and lower contained a considerable amount of free protein along with the protein-polysaccharide complex. The fractions obtained differed by biological properties: fractions with the mol wt of 100000 dalton and over were toxic for mice and possessed weak antigenic properties in the precipitation in agar test and immunoelectrophoresis; fractions with the mol wt lower than 30000 dalton expressed in the mentioned test distinct antigenic properties and proved to be practically nontoxic for mice. Thus the use of diafiltration method permitted to separate the antigenic, weakly toxic component of Ps. aeruginosa mucus from the toxic factor with weak antigenic properties.

[Immunologic study of the cellular components of bacillus pyocyaneus. V. Antigenic analysis of slime and its fractions]. / Immunologicheskoe izuchenie kletochnykh komponentov sinegnoinoi palochki. V. Antigennyi analiz slizi i ee fraktsii.

Various slime fractions were obtained from newly isolated mucoid strains of P. aeruginosa by the method of ultrafiltration or differential centrifugation with subsequent gel chromatography. Purified slime was found to react with a broader spectrum of typing O sera than the corresponding cell wall lipopolysaccharides. Erythrocytic diagnostic preparations produced on the basis of slime antigens allowed to reveale the presence of circulating antibodies against P. aeruginosa. The slime components with molecular weight of 30,000--100,000 daltons and greater contained common antigenic determinants, and the slime components with molecular weight of 10,000--30,000 daltons contained both specific antigenic determinants and those also common to the high molecular components.

[Lipopolysaccharide identification in aqueous extracts of Pseudomonas aeruginosa by an immunoenzyme method]. / Identifikatsiia lipopolisakharida v vodnykh ékstraktakh Pseudomonas aeruginosa immunofermentnym metodom.

To determine the content of lipopolysaccharide (LPS) in P. aeruginosa aqueous extracts the ELISA was used. Membrane filtration and ultracentrifugation followed by precipitation with ammonium sulfate at 80% saturation and gel filtration on Sephadex G-100 have proved to be the most effective methods for purification of the aqueous extract from LPS.