[Approaches to classifying bifidobacteria based on DNA structural data]. / Podkhody k klassifikatsii bifidobakterii na osnove dannykh o strukture ikh DNK.

A brief historical review of classifications of Bifidobacteria demonstrates the difficulties in this problem, for the present-day classifications are far from being satisfactory. Based on the genotypical heterogeneity of the genus Bifidobacterium, the authors validate the possibility of raising it to the status of the family Bidobacteriaceae fam. nov. The principle of forming new genera within the frames of this hypothetical family, discussed in the paper, originates from the genomic similarity of representatives of some species of this group of microorganisms.

[Immunological imbalance in the newborn infant and its correction in a system to prevent neonatal morbidity and infant mortality]. / Immunologicheskii disbalans novorozhdennogo i ego korrektsiia v sisteme preduprezhdeniia neonatal'noi zabolevaemosti i mladencheskoi smertnosti.

Immunological changes were examined in neonates having a different clinical status and varying effects of immunomodulation. The paper shows it expedient to use intravenous immunoglobulin as part of a package of measures to nurse premature neonates. A method for evaluating the responsiveness of immunocytes in the newborn has been developed, which is based on the determination of the equilibrium between activation-induced T-cell proliferation and apoptosis.

[Stable paper indicator systems for rapid identification of microorganisms]. / Stabil'nye bumazhnye indikatornye sistemy dlia uskorennoi identifikatsii mikroorganizmov.

The authors prepared under experimental-industrial conditions paper indicator systems for the express identification of microbes, including carbohydrate discs (by the method of Nikitin et al.), and newly worked out types for the determination of the activity of cytochromoxidase, urease, indol formation, and indicator amino acid decarboxylases (lysin, ornithin, arginine). The use of paper indicator discs proved to be expedient for rationalization of laboratory diagnosis of bacterial intestinal infections.

[Theoretical-experimental study of the process of phage lysis]. / Teoretiko-eksperimental'noe issledovanie protsessa fagolizisa.

The mathematical model of phagolytic process is proposed, taking into account the preexponential phase in the growth of the biomass of bacteria and phages. This phase seems to be connected with the existence of biological inertia in the synthesis of phage and bacterial proteins. Proceeding from the comparison with experiments on E. coli and the corresponding phage, the numerical values of the constants of the model were determined by one of the optimization methods. The comparison of theoretical calculations with the results of experimental studies showed that this mathematical model correctly described the dynamics of phagolysis both in qualitative and quantitative aspects.

[The use of a molecular hybridization method for studying the enterotoxigenic properties of Salmonella]. / Primenenie metoda molekuliarnoi gibridizatsii dlia izucheniia énterotoksigennykh svoistv sal'monell.

The occurrence of the tox gene among 320 Salmonella strains of 23 serovars, differing in their origin, sensitivity to antibiotics, the presence of R-plasmids and a number of biochemical properties, has been studied by the method of DNA-DNA hybridization in situ. Essential differences in the occurrence of the tox gene have been detected both among S. typhimurium hospital strains and strains isolated in sporadic diseases, from the environment, from animals and among salmonellae belonging to different serovars. The direct correlation between the presence of the enterotoxigenicity gene and plasmids controlling resistance to antibiotics in Salmonella strains has been established. The expediency of using the method of gene probing for the study of the enterotoxigenic properties of salmonellae has been substantiated.

[Distribution of phage-resistant Pseudomonas aeruginosa strains]. / Raspredelenie fagoustoichivykh shtammov Pseudomonas aeruginosa.

The sensitivity of a number of P. aeruginosa clinical strains to virulent bacteriophages has been studied. Phage-resistant strains have been found to constitute a considerable proportion among the tested P. aeruginosa strains. The strains under study fall into 19 groups differing in their sensitivity to the bacteriophages used in this investigation. The strains belonging to some groups are phenotypically identical to experimentally obtained P. aeruginosa phage-resistant mutants PAO. The use of bacteriophage mutants has made it possible to demonstrate that in most cases the resistance of P. aeruginosa natural strains to type phi k phages is due to disturbances in their adsorption, whereas their resistance to type phi m and phi mn phages is, seemingly, not linked with disturbances in their capacity for adsorption on the cell membranes of the bacteria.

[Removal of biologically active admixtures from immunoglobulin preparations]. / Udalenie biologicheski aktivnykh primesei iz preparatov immunoglobulinov.

Inclusion of an additional treatment of the products obtained at centrifugation stages b1 and b13 with activated bentonite and aluminium hydroxide into the alcohol method for the production of immunoglobulin from placental and abortion blood permits obtaining preparations with lowered content of proteolytic enzymes and thermostable acid phosphatase, free from chorionic gonadotropin and blood pigment. The treatment of the final preparation with DEAE cellulose removes blood group antigens from immunoglobulins. The preparations obtained by this method have been shown to meet the requirements for immunoglobulins imposed by technological specifications.

[The traditional classification and genetic systematics of bacteria in the genus Lactobacillus]. / Traditsionnaia klassifikatsiia i genosistematika bakterii roda Lactobacillus.

The classification of bacteria of the genus Lactobacillus has virtually been constructed according to generally accepted peculiarities of the carbohydrate metabolism of the 3 selective groups. The information about the nucleotide contents of DNA (%GC) allows to divide all of 67 species included in the genus into 4 "nucleotide" group according to genosystematics principles. The first group species has %GC = first--49-53, second--42-46, third--34-41 and fourth--32-37. In this manner, it will be singled out 4 new genera in a new proposed family Lactobacillaceae comb.nov.: Thermobacterium comb.nov., Streptobacterium comb.nov., Mediumbacterium comb.nov., and Betabacterium comb.nov. correspondingly. For further revision of the systematics of the bacteria of the Lactobacillaceae family comb.nov. in the direction of approaching its to the natural one it is essential to study of the degree of genome similarities of species representatives within being outline 4 "nucleotide" group both the molecular hybridization using the specific DNA probes and the restriction analysis of the chromosomal DNA (dactyloscopy genome technique).

The possibility of differentiating Vibrio and Aeromonas on the basis of correlation of the nucleotide composition of DNA and the peculiarities of the antigenic structure.

The nucleotide composition of DNA was correlated with the peculiarities of the antigenic structure of vibrios and aeromonades. The authors propose a supplementary test for the differentiation between these microorganisms by the detection of thermolabile "indicator" antigens, most characteristic of cholera vibrios and pathogenic NAG vibrios, in immunoelectrophoresis with diagnostic serum to alcoholic preparation of NAG-vibrio flagellin.

[Genetic determinants of antibiotic resistance in bacteria of the genus Salmonella]. / Geneticheskie determinanty rezistentnosti k antibiotikam bakterii roda Salmonella.

Distribution of genetic determinants of resistance to streptomycin, kanamycin, chloramphenicol, tetracycline, sulfanilamides and trimethoprim in strains of Salmonella isolated from studied. The majority of the resistant strains carried the genes of aminoglycoside-3"-phosphotransferase, type I aminoglycoside-3'-phosphotransferase, type I chloramphenicol acetyltransferase and type II dihydropteroate synthetase. Tetracycline resistance in the strains was often due to the class B tetracycline resistance genetic determinants. It was suggested that the resistance mechanisms controlled by these genes provided higher levels of resistance to the above drugs in Salmonella as compared to the other mechanisms. Plasmid resistance genes were detected in more than 90 per cent of the clinical strains and in 35 per cent of the sporadic strains of S. typhimurium. The antibiotic resistance of the Salmonella strains of other serovars was not as a rule controlled by the plasmid genes.

[Significance of the antibiotic resistance of the causative agents of salmonellosis in its epidemiology and the procedure for controlling the infection]. / Znachenie antibiotikorezistentnosti vozbuditelei sal'monelleza v épidemiologii i taktika bor'by s infektsiei.

Antibiotic resistance of a wide set of strains (1501) of different serovars (69) was studied and the nature of the resistance was determined. Virulent bacteriophages designed with regard to the biological properties of the isolates were considered as possible agents for the control of antibiotic-resistant microorganisms. It was shown that multiple resistance to antibacterial drugs was mainly characteristic of the serovar of S. typhimurium. In Gorky and its region, strains carrying R plasmids determining the resistance to tetracycline and chloramphenicol with a molecular weight of 58-64 Md predominated. The antibiotic-resistant strains were dangerous from the epidemiological point of view. The use of the bacteriophages is advisable for the treatment of patients, sanation of bacterial carriers or decontamination of disease sources and prophylactic phaging with regard to the epidemiological indications for preventing group diseases.