[Epidemic strains of different plasmidovars of bacteria from Shigella genus].

Plasmid analysis of 46 strains of Shigella species confirmed the view about heterogeneity and variability of plasmids composition in these microorganisms. On the other hand,the presence of low-molecular, multiplicated extrachromosomal replicons, which were stable, was shown. Using them, it was possible to divide the Shigella isolates into two major plasmidovars, characterize them according to repertoire of the most stable plasmids and determine epidemically significant variants during sporadic and outbreak incidence of shigellosis in towns Nizhny Novgorod and Kstovo (Nizhny Novgorod region).

[Plasmid analysis of bacteria of Bacillus genus used in the development of probiotics].

Presence of plasmid-contained strains in probiotics prepared on the basis of Bacillus bacteria was assessed. Plasmid analysis was performed by the method based on neutralization of bacterial suspension after alkaline treatment with lithium chloride. Presence of 4-6 plasmids with molecular weight from 1 to 75 MDa was revealed in 4 commercially available probiotics. Since plasmids can facilitate transfer of genes of the antimicrobial resistance to pathogenic microorganisms it was recommended to perform thorough search of probiotic microorganisms without plasmids or ensure the elimination of R-plasmids in start cultures for the most promising biopreparations.

[Pseudomonas rathonis--a new species of "Pseudomonas aeruginosa-complex"].

Pseudomonas strains (n = 8), isolated from soil and attributed to a new species of Pseudomonas rathonis have been studied by the methods of polyphasic taxonomic analysis. The data of 16 S rRNA sequence, sequence of gyr B-gene, DNA-DNA molecular hybridization, data of fatty acid composition and phenotypical analysis proved, that the studied bacteria belonged to "Pseudomonas aeruginosa-complex". The set of characteristics to differentiate Pseudomonas rathonis from other 11 species of this complex has been proposed.

[Evaluation of the bacteriological safety of wares made from different metals].

The determination of the integral toxicity of a liquid after its contact with different metallic wares could provide a comparative assessment of the hazards of this ware to living organisms. The distilled water and physiological solution exposed to silverware even for a short period of time (15 min) proved to be deleterious to the specially selected bacterial strains differing in their resistance to different chemical substances while aluminum ware was quite harmless to them after their long (4-day) standing of liquids.

[Taxonomic analysis of Pseudomonas strains with uncertain taxonomic status]. / Taksonomicheskii analiz shtammov bakterii roda Pseudomonas s neopredelennoi vidovoi prinadlezhnost'iu.

Pseudomonas strains isolated from soil and rhizosphere and designated as "Pseudomonas rathonis", Pseudomonas sp. B and Pseudomonas sp. C have been characterized by 113 phenotypic properties and studied by methods of molecular-genetic analysis. The 5'-terminal hypervariable 16S rRNA regions, containing from 208 to 344 nucleotides have been amplified and sequenced. The comparative analysis of sequence results gave evidence about phylogenetic relatedness of studied bacteria (98-100% of 16S rRNA sequences identity) to some saprophytic and plant-pathogenic Pseudomonas species. The latter substantially differed from studied strains in phenotypic characteristics. The DNA-DNA hybridization results have shown the low (0-36%) level of chromosomic DNA homology of "Pseudomonas rathonis", Pseudomonas sp. B, Pseudomonas sp. C strains with the type strains of P. fluorescens, P. putida, P. mendocina, P. pseudoalcaligenes. Obtained data give evidence that these strains belong to some novel Pseudomonas species.

[Industrially produced eubiotics as materials for isolation and study of DNA]. / Eubiotiki promyshlennogo izgotovleniia kak material dlia vydeleniia i izucheniia DNK.

The optimum and available methods for the isolation of DNA from bacteria, used as the basis of the industrial manufacture of eubiotics (colibacterin, lactobacterin, biobactone) have been developed. The proposed approach makes it possible to isolate DNA, suitable for genosystematic studies under laboratory conditions, directly from producer strains.

Phenotypic diversity of Pseudoalteromonas citrea from different marine habitats and emendation of the description.

Four strains of marine, aerobic, agar-decomposing bacteria with one polar flagellum and with DNA G + C contents of 38.9-40.2 mol% were isolated from the Far-Eastern mussels Crenomytilus grayanus and Patinopecten yessoensis. These four strains were identified as Pseudoalteromonas; however, they were phenotypically different from species described previously according to carbon compound utilization tests and the BIOLOG identification system. High agar-decomposing activity was found in two strains, in one of which agarase, alpha-galactosidase, pustulanase and laminarinase had been detected. The level of DNA homology of three of the strains was 70-100%. The fourth isolate was genetically less related to the others (67% DNA relatedness) and phenotypically was more distant from other members of this group; however, all four strains were assigned to a single species genotypically. DNA from the strains isolated from mussels showed 40-45% genetic relatedness with the DNA of Alteromonas atlantica, 8-36% with DNA of Pseudoalteromonas haloplanktis subsp. haloplanktis, Pseudoalteromonas haloplanktis subsp. tetraodonis, Pseudoalteromonas undina, Pseudoalteromonas nigrifaciens and Pseudoalteromonasas carrageenovora, 53% with Pseudoalteromonas elyakovii, 32-48% with marine P. nigrifaciens from mussels and 14-16% with Alteromonas macleodii. The DNA-DNA hybridization data revealed that the levels of relatedness between the strains isolated and the type strains of Pseudoalteromonas citrea and Pseudoalteromonas fuliginea described recently were significant (95-85%). These results were confirmed by serological data employing polyclonal antibodies to cell surface antigens. The strains isolated from mussels were identified as P. citrea. The hybridization data showed that the name P. fuliginea Romanenko et al. 1994 should be recognized as a junior subjective synonym of P. citrea Gauthier 1977. A notable phenotypic diversity of P. citrea which might be a reflection of their ecological habitats is discussed.

[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.

[Improvement in the species identification of Lactobacillus by using microculture test systems and data on its genome structure]. / Sovershenstvovanie vidovoi identifikatsii laktobatsill s ispol'zovaniem mikrokul'tural'nykh test-sistem i dannykh o stroenii genoma.

18 microanalytical media, used for the construction of a biochemical plate test system permitting the specific identification of bacteria of the genus Lactobacillus, were developed on the basis of data on the metabolic activity of these bacteria and their need of growth factors. As the results of studies made on 78 Lactobacillus strains with the use of traditional microbiological and gene-systematizing methods, the proposed test system was shown to be reliable and specific.

[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).

[Plasmid analysis of cadmium- and penicillin-resistant strains of staphylococci isolated in maternity hospitals]. / Plazmidnyi analiz kadmii-penitsillinorezistentnykh shtammov stafilokokkov, vydelennykh v akusherskikh statsionarakh.

The plasmid analysis of a collection of the staphylococci isolated was made in the obstetric hospitals of Nizhny Novgorod and Arzamas in 1986-1989. It revealed the presence of large complex plasmids with a molecular weight of 22 MD carrying the determinants of resistance to penicillins and cadmium and mercury ions in polyresistant strains. Conjugation transfer of the plasmid even between the staphylococci of different species was performed under experimental conditions. It was suggested that occurrence of the strains carrying the complex cadmium-penicillinase plasmid was due to violation of the sanitary or ecological requirements.

[The isolation of Vibrio fluvialis on the territory of the USSR]. / O vydelenii Vibrio fluvialis na territorii SSSR.

For the first time V. fluvialis strains were detected on the territory of the USSR. The taxonomic position of these vibrios was determined by their nucleotide DNA composition (the content of guanine + cytosine was 49.3-51.0 mole%) and the characteristic features of their phenotype. The individual features of the strains consisted in their capacity for agglutination with cholera antisera, groups 01 and Inaba, in diagnostic dilutions in the presence of differences in genomes and phenotypes with cholera vibrios. Molecular hybridization DNA-DNA also gave no confirmation of their relationship to cholera vibrios (23-26% homology). The comparative study of V. fluvialis strains from the USSR and other countries by a broader set of their phenotypical signs confirmed their identity.