[Cross infection of guinea pigs with different pneumococcal serotypes in the presence of the carrier state]. / Perekrestnoe zarazhenie morskikh svinok pnevmokokkom raznykh serotipov na fone nositel'stva.

The possibility of the pneumococcal cross infection of guinea pigs in experimental conditions, the time course of the distribution of pneumococci in their organs, and the duration, within the time limits of the experiment, of persistence of the given infective agent were studied. Normal animals placed in the same room with infected ones were shown to become the carriers of definite pneumococcal serotypes. As a result, these studies revealed that nasopharyngeal carriership and infection of different organs were not directly interrelated and the method of infection of guinea pigs did not influence the time course of distribution of pneumococci in their organs. The data on the duration of persistence of the infective agent, as well as on the importance of this phenomenon for determination of the relationship between pneumococcal carriership and disease, are presented.

[Nutrient medium for the isolation and cultivation of pneumococcus]. / Pitatel'naia sreda dlia vydeleniia i kul'tivirovaniia pnevmokokka.

A culture medium for the isolation and cultivation of pneumococci, produced in a solid or liquid form and based on raw material unsuitable for use as foodstuff (human placenta), has been developed. The amino acid composition of the medium has been studied. The medium has been found to contain 19 amino acids, to be free from ballast serum proteins and blood, and to ensure the good growth of pneumococci isolated from pathological material, the formation of the normal capsule, as well as active biological properties. The medium has proved to create elective and selective conditions enhancing the effectiveness of investigations and simplifying the isolation of pneumococci in the microbiological examination of patients.

[Sensitivity of different mouse strains to Streptococcus pneumomiae serotype 3]. / Chuvstvitel'nost' razlichnykh linii myshei k Streptococcus pneumoniae serotipa 3.

The sensitivity of different mouse strains to Str. pneumoniae, serotype 3, after the intraperitoneal injection of the infective agent was studied. These experiments revealed that the animals under study, so far as their susceptibility and sensitivity were concerned, formed a single group, highly sensitive to this serotype. The sublethal dose of the pneumococcus was determined. The distribution of pneumococci in the organs during a definite time interval was shown and the fact of the prolonged carriership of the capsular forms of the pneumococci was established.

[Biological properties of the antigens isolated from Streptococcus pneumoniae serotype 3]. / Izuchenie nekotorykh biologicheskikh svoistv antigenov, vydelennykh iz Streptococcus pneumoniae serologicheskogo tipa 3.

The protective activity of polysaccharide-containing antigens of Str. pneumoniae, serotype 3, was studied. The protective properties of the preparation were shown to be directly related to the quantitative content of carbohydrate substances, and the preparation was shown to be capable of inducing specific resistance. The study revealed that the resistance of mice to infection with the virulent strain of Str. pneumoniae, serotype 3, did not ensure the rapid elimination of the infective agent from the body. The antimicrobial effect of the preparation was due to the presence of protein, not subjected to deproteinization.

[Pneumococcal serotypes in various diseases of children]. / Serotipy pnevmokokkov pri razlichnykh zabolevaniiakh detei.

The serotyping of pneumococci isolated from different material obtained from children aged 0 to 11 years was carried out. Out of 156 patients with different diseases, hospitalized in two clinics in Moscow during February-May 1983, pneumococci were isolated from 67 patients (43%). The isolated pneumococcal strains belonged to 11 serotypes. Pneumococci of serotypes 3, 6, 9 and 19 were shown to occur most frequently in different diseases and constituted 50% of the isolated strains. The inoculation of the material by the quantitative method permitted the authors to find out the role of pneumococci as the etiological factor in the pathogenesis of some diseases. A certain dependence of diversity in the types of isolated pneumococci on the age of sick children was noted. Almost all isolated strains were found to be sensitive to penicillin, ampicillin and benzylpenicillin. But a few individual strains were sensitive only to one of these antibiotics. The data on some biological properties of pneumococci cultivated on solid culture media are presented.

[Type-specific pneumococcal agglutinating sera in precipitation tests]. / Izuchenie tipospetsificheskikh aggliutiniruiushchikh pnevmokokkovykh syvorotok v reaktsiiakh pretsipitatsii.

Diagnostic agglutinating sera to pneumococci of different serotypes have been studied with respect to their capacity for taking part in the reactions of precipitation with capsular pneumococcal polysaccharides. The sera have proved to be highly active and specific in the reactions of double immunodiffusion and immunoelectrophoresis. The sera under study have also been found to react with cattle serum, one of the components of the medium used for the cultivation of pneumococci.

[Persistence of pneumococci in mice]. / Persistentsiia pnevmokokka u myshei.

The sensitivity of different mouse strains to Str. pneumoniae, serotype 6, under the conditions of intraperitoneal and intranasal infection has been studied. The time course of distribution of pneumococci in the organs has been shown and differences depending on the methods of infection have been revealed. The pathomorphological and immunomorphological changes in the organs and tissues after the introduction of the infective agent by different methods have been established.

[Increase in the coefficient of component utilization by balancing the composition of the nutrient medium for growing pneumococci]. / Povyshenie koéffitsienta ispol'zovaniia komponentov pri balansirovke sostava pitatel'noi sredy dlia vyrashchivaniia pnevmokokkov.

The possibility of using the experimental-analytical balance method (EABM) for development of balanced media, optimal and economic by their composition is shown. The method is based on the specific growth activity of the medium components and mathematical calculation of their concentrations. A balanced medium containing human placenta hydrolysate was developed. The medium has a high component consumption coefficient and provides maintenance of high levels of the pneumococcal culture biological properties such as growth, capsule formation, virulence and agglutinability. The quantities of nutrient yeast extract, cystine, glucose and sodium chloride in the balanced medium are 2, 18-20, 4-4.7 and 32-33 times lower respectively than those in the initial medium. The use of the balanced medium instead of the initial unbalanced one or instead of the meat medium based on the Hottinger broth will provide the total economy of 1010 or 2360-2580 roubles respectively per. 1000 liters of the medium. It is concluded that a wider use of this method in optimization of microbiological nutrient media in production of medical and biological preparations is promising.