[Cultivation of asporogenous anaerobic microorganisms in media of various compositions]. / Kul'tivirovanie nesporogennykh anaérobnykh mikroorganizmov v sredakh razlichnogo sostava.

The comparative evaluation of the quality of experimental dried culture medium for the isolation and cultivation of anaerobic microorganisms, developed on the basis of locally produced ingredients without unavailable raw material suitable for human consumption, and enriched thioglycolic medium has revealed the advantage of the former and permits its recommendation for practical use in laboratories.

[Use of an experimental analytical method for equilibrating nutrient broths for Clostridium perfringens type A growth and toxin formation]. / Ispol'zovanie éksperimental'no-analiticheskogo metoda dlia balansirovki zhidkikh pitatel'nykh sred dlia rosta i toksinoobrazovaniia Clostridium perfringens tipa A.

A successful attempt to use analytico-experimental approach to the evaluation of experimental data for the scientifically based calculation of the composition of complex culture media, intended for growing pathogenic microorganisms, has been made. The method is based on the evaluation of the specific growth-stimulating and toxin-forming activity of the components of a given culture medium, which are determined by the number of cells grown in the variants of the medium with the limited amount of one of its components. The use of the analytico-experimental balancing method makes it possible to develop culture media with the optimal composition ensuring the definite yield of the target product rather quickly and economically by experimenting on the minimal number of variants equal to the number of the components of the medium. The investigation carried out by means of the analytico-experimental method has revealed that on the basis of peptic serum albumin hydrolysate, pancreatic casein hydrolysate and fodder yeast extract, alongside the culture medium described in an earlier work and containing these components in the proportion 4:2:1, two other media, containing the above components in the proportion 2:4:1 and 3:4:2, can be obtained, these media providing the optimal conditions for, respectively, the toxin formation and growth of C. perfringens, type A.

[Effect of iron on the growth and toxin formation of Clostridium perfringens type A cultures]. / Izuchenie vliianiia zheleza na rost i toksinoobrazovanie kul'tur Clostridium perfringens tipa A.

The influence of iron at different concentrations on the growth and toxin formation of the cultures of C. perfringens strain 28 BP6K, type A, in media having different composition and protein base has been studied. As revealed by the results of these studies, bivalent iron at concentrations of 1-30 mg%, while having no essential influence on the growth and development of the culture, not only produces no stimulating effect on toxin formation, but even inhibits it. The concentrations of iron, both producing the optimum effect on toxin formation and inhibiting it, are not identical for different kinds of culture media and depend on their nature and composition. In culture media with fodder yeast extract added, and especially in media based on fermentative fodder yeast hydrolysate, the cultures have shown the increased stability of toxin formation in the presence of higher concentrations of iron.

[Antigenic fractions of Clostridium oedematiens toxin and their immunogenic properties]. / Antigennye fraktsii toksina Clostridium oedematiens i ikh immunogennye svoistva.

The results of the isolation of antigenic fractions and their complexes from Cl. oedematiens toxin and the study of their antigenic properties are presented. The purified, concentrated toxin has been found to consist of high- and low-molecular antigens differing in immunogenicity and affinity to aluminium hydroxide used as sorbent. Preparations obtained from low-molecular antigens easily adsorbed by the low doses of the sorbent possessed high specific and immunogenic activity.

[Comparative study of the physico-chemical properties of peptones used to the production of dry alkaline agar for cholera diagnosis]. / Sravnitel'noe izuchenie fiziko-khimicheskikh svoistv peptonov, ispol'zuemykh v proizvodstve sukhogo shchelochnogo agara dlia diagnostiki kholery

The authors present the results of chemical and physico-chemical study of dry peptones (made in the USSR) used in the production of dry alkaline nutrient agar for the diagnosis of cholera, in comparison with peptones used for other purposes. The batches and types of peptones studied differed by the fractional peptide composition and by the physico-chemical characteristics. Positive results were obtained in the biological test in using peptones with marked hydrolysis with the amine nitrogen content of not less than 200--230 mg%, with an elution curve approaching the Hottinger's peptone curve, well soluble in buffer phosphate solution at 5% concentration.

[Study of the interrelationship between the content of immunizing units and the immunogenicity of C1. perfringens anatoxins]. / Izuchenie vzaimosviazi mezhdu soderzhaniem immuniziruiushchikh edinitis i immunogennost'iu anatoksinov C1. perfringens

Comparative experiments were conducted on rabbits and guinea pigs; a study was made of the immunological efficacy of the toxoids with a different content of the immunizing units (IU/ml). There was revealed a regular quantitative interrelationship between the content of the IU/ml in the toxoids, the level of the antitoxin formation and the extent of protection against the experimental gas gangrene in the immunized animals.

[Method of determinating the protective capacity of C1. perfringens toxoid]. / K metodike opredeleniia zashchitnykh svoistv anatoksinov C1. perfringens

The authors describe a model of experimental gas gangrene in guinea pigs; it was produced by the administration of the vegetative form of C. perfringens; the cells were completely washed of the lethal toxin and no toxic or necrotizing agents were added. A possibility of development of gangrenous process without any preliminary depression of the resistance of body tissues in the area of injection of the causative agent was revealed. Apart from the local process and general intoxication gas gangrene, caused by intramuscular injection of C1. perfringens to guinea pigs, was accompanied by bacteriemia and microbial contamination of the internal organs. A method of the animal infection was ascertained and the causes of their death was assessed. The method is recommended for determination of the immunological efficacy of C1. perfringens toxoids.

[Detoxification of a purified concentrated C1. oedematiens toxin]. / Obezvrezhivanie ochishchennogo kontsentrirovannogo toksina C1. oedematiens

One of the stages of a new technological scheme for obtaining C1. oedematiens toxoid (detoxication with formaldehyde of a purified concentrated toxin) was elaborated under experimental conditions. It was found that under the effect of increased formalin concentrations (0.4--0.2%) or of prolonged action of heat there developed in the toxin a reduction of antigenic activity, expressed on immunoelectrophoregrams in the form of a change of surface potential of one of the electrophoretic fractions. Detoxication of the purified concentrated C1. oedematients toxin occurred in the course of 3 days without any losses of its antigenic activity under the following conditions: formalin concentration 0.1%, temperature 37-38 degrees C, pH L.7--6.9. No reversion of toxicity of the preparations detoxified under the mentioned conditions was revealed under the action of formalin-binding agent (sodium sulfite) on them.