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The identification of probiotic strain Lactobacillus sp. 55 at species level on the basis of analysis of the 16S rRNA gene nucleotide sequences has been done. It has been established that investigated strain belongs to the species Lactobacillus gasseri. The nucleotide sequence of strain Lactobacillus gasseri 55 16S rRNA gene’s fragment has been deposited in international database GenBank (NCBI) under number 314159 KT.

The strains of lactic acid bacteria have been isolated from the intestine of older women. These strains were identified and their biological activity was studied. It has been established that Lactobacillus acidophilus, L. plantarum, L. salivarius var. salivarius and Enterococcus faecium had the highest antagonistic activity against opportunistic microorganisms. It has been revealed, that the adhesive properties and antibiotic resistance of the tested cultures had strain specificity. Most of the isolates were highly adhesive and did not produce hemolysins.

Composition of lactic acid bacteria and bifidobacteria in raw milk and home-made milk products has been analyzed using real-time PCR (quantitative PCR) with genus-specific primers to Enterococcus, Lactobacillus and Bifidobacteria. Bacteria belonging to these genera have been revealed in all samples analyzed (milk, sour cream, cottage cheese). It has been shown that the representatives of Enterococcus and Lactobacillus genera dominated in the samples analyzed (10(3)-10(7) genome equivalent/ml (mg)). The largest number of these microorganisms (10(7) genome equivalent/mg) has been detected in cottage cheese.

The methods of Gram-positive cells disintegration to obtain cell wall fragments have been described. It has been shown that the use of ultrasonic disintegrator UZD-500 at the frequency 22 kHz during 30 min is optimal for disintegration of lactic acid bacteria cells. Also the ability to use grinding of cells in liquid nitrogen (6 times to the complete evaporation) for obtaining the cell wall fragments has been demonstrated.

Lactic acid bacteria and bifidobacteria were isolated from the samples of dry microbial substance "Vivolac" and identified. The lactic acid bacteria were identified as Lactobacillus acidophilus. L. delbrueckii subsp. bulgaricus, L. paracasei. Bifidobacteria belonged to the species Bifidobacterium animalis. Manifestation of biological activity of all studied strains was investigated. It was shown, that adhesive activity of the studied strains depended on the genus of the strain: lactobacilli manifested medium adhesiveness to buccal epithelium (medium adhesive index 2.07-2.26), bifidobacteria manifested high adhesiveness (medium adhesive index 4.11-4.76). Antagonism against pathogenic and opportunistic reference strains was manifested to a greater extent to Pseudomonas aeruginosa. Lactobacilli and Bifidobacteria were resistant to aminoglycosides. Sensitivity of the studied strains to antibiotics did not depend on the genus and species of microorganism. Lactobacillus and Bifidobacterium strains were capable to survive in gastric juice and at different concentration of bile, which is promising for development of probiotic preparations on the basis of these strains.

The reversion of the antibiotic sensitivity of lactic acid bacteria: Streptococcus salivarius subsp. thermophilus, Enterococcus faecium, Lactobacillus plantarum have been studied. The phenomenon of the reversion has been fists studied in lactic acid bacteria of different taxonomic groups at their interactions with lymphoblastoid human cells. It is shown that resistance of lactobacteria to antibiotics can change depending on the terms of cultivation, genus and strain specificity. Most often the reversion of antibiotic sensitivity was observed with respect to fuzidin (26%) and cefepim (23%), most rarely--with respect to cephazolin, erithromicin, cefamandol, tobramicin and oxacillin.

The influence of the AB0 blood groups on adhesion of different lactic acid bacteria species was studied. From twelve investigated strains of Streptococcus salivarius subsp. thermophilus, Enterococcus faecium, Lactobacillus acidophilus, L. plantarum and L. delbrueckii subsp. bulgaricus species, difference between adhesion average index on erythrocytes of various blood groups was found in two strains. The average adhesion index of the strain E. faecium K-50 in A (II) blood group erythrocytes was higher (AAI = 4.91 +/- 0.26) than in B (III) blood group erythrocytes (AAI = 4.17 +/- 0.33). The strain L. delbrueckii subsp. bulgaricus 4n has displayed a higher adhesive activity in A (II) blood group erythrocytes (AAI = 4.36 +/- 0.13) in comparison with AB (III) blood group erythrocytes (AAI = 3.61 +/- 0.75).

A comparative research of the structure of vaginal and intestinal microflora in norm and at kidney pathologies in women in the prenatal period was carried out. At physiologically normal course of pregnancy microbiocenosis of vagina and intestine does not contain pathogenic and conditional-pathogenic microorganisms. Lactic acid bacteria are fixed within the limits of 10(5)-10(8) CFU/1 ml in the vagina secretion and 10(7)-10(8) CFU/1 g in the intestine content. The spore microorganisms have completely disappeared in vaginal biocenosis of women with pyelonephritis after pharmacotherapy; and colibacterias has disappeared in 62% of women. Quantity of lactic acid bacteria has also decreased. Quantity of E. coli (10(8)- 10(9)) CFU/g, sporous microorganisms (10(3)-10(4)) CFU/g and yeast (10(4)-10(5)) CFU/g has considerably increased in the content of intestine. Lactic acid bacteria in content of the vagina are presented by: Lactobacillus acidophilus, L. plantarum, L. fermentum, L. vaginalis; in content of the intestine--L. plantarum and L. fermentum. All the isolated strains of lactobacilli are resistant to metrogyl and amphotericin, 87%--to cephoxitine, cypropfloxacine. Twenty three of 24 strains of lactic acid bacteria--antagonists of pathogenic microflora have shown adhesion to vaginal epthelium. The degree of adhesive activity depends on the strain and genus specificity of cultures. The highest index of adhesiveness in indicated in Enterococcus faecium (5.82 - 7.62) and Streptococcus salivarius subsp. thermophilus (2.74 - 6.40) strains. The screening of strains has been performed, which suppress growth of gas-producing microflora. The strain of Lactobacillus plantarum 200D proved to be the most active one. A complex of cultures of the lactic bacteria providing normalization of microbial cenosis of the vagina in women in the prenatal period has been selected as based on the data obtained. The biotechnology of production of vaginal suppositories is developed.

Current status of the question concerning the study of lactic acid bacteria adhesion process is presented in the review. Lactic acid bacteria colonization capacity allows them to form monolayers, to join the mucosal microbiota, to become a component of ecological barrier, which protects an organism from penetration of pathogens. The available methods of investigation of adhesive properties such as microbiological, light and electron microscopy, biophysical, mathematical and others are presented in detail. The works concerning lactic acid bacteria adhesines nature and factors that influence the exhibition of adhesion have been analyzed. Studies concerning the mechanisms responsible for attachment of cells of lactic acid bacteria to the surface of different types of epithelium and substances that are products of endothelium secretion are analyzed. Questions on adhesion specificity and factors that inhibit its exhibition are considered. The chart of current concept of the adhesive process and factors that reciprocally affect the exhibition of lactic acid bacteria adhesion properties is developed and presented by the authors.

The numeric analysis of 14 strains of lactobacilli investigated by 57 phenotypical characteristics, has resulted in formation of three clusters: group L. delbrueckii, L. plantarum and the modular group formed by strains of various species. The API-testing, 16S rRNA sequencing and RAPD-typing with primers 5'-AGCAGCGTGG-3' and LP3-ST 5'-TGGTCCGAGC-3' have been carried out for several strains which position in a dendrogram did not correspond to their species diagnosis. The obtained data have allowed the reclassification of the strain L. delbrueckii subsp. bulgaricus B-1923T as L. plantarum B-1923T, L. agilis B-2603 as L. fermentum B-2603, L. amylophilus 30/4/(2) as L. plantarum 30/4/(2). Strain L. confusus 39T, identified by the phenotypical characteristics and data of API-testing as L. fermenturm, was reclassified on the basis of the phylogenetic analysis and RAPD-typing, as L. pentosus 39T.

During investigation of adhesive properties of lactic acid bacteria it was found out that 11 strains adhered to buccal intestinal and vaginal epithelium of human. The highest adhesive activity was detected in enterococci (adhesive index 7.75-14.26), lower one--in streptococci (6.40-9.16). In lactobacilli adhesive properties manifested in different ways: Lactobacillus acidophilus strains adhered more often to buccal epithelium (2.58-4.60) and rarely--to intestinal and vaginal. L. plantarum manifested high adhesive activity (8.03 -9.69) to buccal epithelium and lower one--to the rest of epithelium types. Monosaccharide composition of glycocalix of 6 strains of lactic acid bacteria was studied to understand the adhesion mechanism. It was shown that surface structures of this microorganism interact with plant lectins, specific to certain monosaccharides.

The strains of lactic acid bacteria (n = 139) belonging to Lactobacillus, Streptococcus, Enterococcus and Leuconostoc genera have been studied. It has been shown that neither of the strains used cholesterol as a source of carbon. Some strains (13.6%) hydrolyzed actively the conjugates of bile acids. The hydrolyzed activity displayed to a higher extent in anaerobic conditions on the medium with glucose. Hydrolase of conjugates of bile salts, which precipitated under acid value of pH and were excreted from the organism, was contained in 29% of 69 studied strains of lactic acid bacteria. Cholesterol is also removed from the organism under the same pH values that is confirmed by clinical tests of the product "Gerolakt Kislomolochny" (lactic-acid Gerolact).

Primers LP1-LP2 to the gene 16S rRNA have been developed, which permit to differentiate lactic acid bacteria: Lactobacillus plantarum, L. delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus. The strain-specific and species-specific differentiations are possible under different annealing temperature. Additional fragments, which are synthesized outside the framework of gene 16S rRNA reading, provide for the strain-specific type of differentiation, and the fragment F864 read in the gene 16S rRNA permits identifying L. plantarum.

The preliminary test of carbohydrates fermentation has been carried out to confirm a regular position for some lactic acid bacteria strains. Restriction cards have been compiled for Lactobacillus plantarum, L. delbrueckii and Streptococcus salivarius using Vector NTI program. A comparative analysis of the restriction cards has shown presence of unique sites of restriction endonucleases, which can be used for differentiation of the above-stated species.

REP- and ERIC-PCR genome analysis of lactic acid bacteria of genera Lactobacillus and Streptococcus have shown the presence of REP- and ERIC-repetitive sequences with high degree of homology. Amplification products which separation in agar gel results in formation of a specific fingerprint are obtained under REP- and ERIC-PCR. It is shown that REP- and ERIC-specific primers can be used for PCR identification of both enterobacteria and lactic acid bacteria isolated from different ecological niches.

Availability of certain monosaccharides in the composition of glycocalyx of lactic acid bacteria (Lactobacillus plantarum--strains 337D and 11/16; Streptococcus thermophilus--strains S1 (nonmucous race) and S5 (mucous race), Enterococcus faecium (K-50) has been investigated with the help of plant lectins with certain carbohydrate specificity labelled by colloid gold. All the microorganisms under investigation were characterized by the presence of N-acetyl-D-galactosamine and N-acetyl-D-glucosamine in rather insignificant amounts. Glycocalyx of lactic acid bacteria was also characterized by availability of essential amount of L-fructose and low amount of sialic acid (except for S. thermophilus S5 (mucous race). Presence of alpha-N-acetyl-D-galactosamine, alpha-D, beta-D-galactose, alpha-D-glucose, alpha-D-mannose in the composition of the lactic acid bacteria glycocalyx composition evidences for the additional role of these monosaccharides in the process of the microorganism adhesion on the human and animal intestine mucosa. It has been confirmed that availability of certain monosaccharides in the composition of surface glycopolymers of lactic acid bacteria was connected with adhesive properties of cells and their existence conditions.

Health effects of fermented milks have been associated with the metabolic activity of lactic acid bacteria in the gastrointestinal tract. It has been proposed that an increased excretion of urea nitrogen via microbial protein may decrease the workload on kidneys and liver. Therefore, a study was carried out in healthy elderly human subjects to investigate the incorporation of [15N2]urea nitrogen into plasma and fecal proteins and amino acids. Over a period of 10 d 13 healthy elderly subjects ingested daily a freeze-dried microbial preparation which contained different genera of lactic acid bacteria and is used to produce fermented milk products. One of the strains was originally isolated from stool samples of elderly people from the Caucasus region (Lactobacillus plantarum). No stimulation of fecal protein-nitrogen excretion and no increase in 15N-abundances in fecal protein was measured following the administration of the viable microbial preparation and a [15N2]urea bolus. Tentatively, it was concluded that this may have been caused by the inability of the microbial culture to survive the gastro-intestinal passage and (or) by the absence of additional fermentable carbohydrates in the diet as energy source for bacterial protein synthesis in the large intestine. However, using a highly sensitive GC-C-IRMS method we observed a significant incorporation of 15N into plasma protein amino acids. 15N-Enrichments in single amino acids were found according to their participation in transamination reactions. The slight enrichment of lysine which is not transaminated in mammalian tissues may indicate a microbial synthesis and absorption of bacterial lysine.

Lysozyme-synthesizing activity of a large collection of cultures of lactic-acid bacteria isolated from various natural substrates has been studied. It is shown that the degree of lysozyme production depends on the source of bacteria isolation. Representatives of Enterococcus genus isolated from the digestive tract of long-living people, as well as fishes, geese and ducks are most active among the coccal forms. Manifestation of lysozyme-synthesizing activity in lactobacilli depends on the group and species belonging of strains. It is established that the capacity to produce lysozyme can serve a diagnostic characteristic under identification of lactobacillus of subgenus Betabacterium. Lysozyme produced by lactic acid bacteria is one of the components in the total complex of the mechanism of biological activity of this important group of microorganisms.

One hundred and thirty six Lactobacillus strains isolated from poultry and 23 Lactobacillus strains isolated from long-living persons were tested for their antibiotic sensitivity. Occurrence of some type determinants of resistance to aminoglycoside antibiotics and tetracyclines in the Lactobacillus strains resistant to these antibiotics was studied. The majority of the strains from the both collections were resistant to aminoglycosides (73 and 79 per cent, respectively). The isolates from the poultry were characterized by multiple resistance. The isolates from the long-living persons were most frequently resistant to one of two antibiotics. All the tested Lactobacillus strains isolated from the long-living persons were sensitive to tetracyclines. The species composition of the isolates was different. The antibiotic-resistant strains were detected in all the species involved in the study. By hybridization of Lactobacillus colonies with the probes containing various genes of the resistance it was shown that in 14 per cent of the antibiotic-resistant strains belonging to Lactobacillus the antibiotic resistance was controlled by the genes homologous to resistance genes widely distributed in gramnegative organisms. This indicated a possible wide exchange and heterologous expression of the antibiotic resistance determinants between microorganisms of various taxonomic groups.

The lactic acid bacteria isolated from different ecological niches are established to be able to adhere in vitro to the intestine epithelium of pigs and cattle. The studied strains of enterococci have a higher index of adhesiveness (5.7-2.24) as compared to lactic acid bacilli (3.34-1.08). Detection of the lactic acid bacteria ability to adhere to intestine enterocytes of agricultural animals served as a premise to use those bacteria when constructing preparations of the directed action on the basis of living cultures.

Lactic acid bacteria were either absent or present in negligent quantities in the stomach of apparently healthy man. But in case of various pathological processes in the stomach and duodenum lactic acid bacteria accumulated (up to a million cells per 1 ml of gastric contents). Under these conditions coccal forms sharply prevailed over the bacillary ones. In patients with chronic gastritis and peptic ulcer of the stomach the most frequent were Streptococcus faecalis and its variants; in oncological patients--Str. faecium, strains affiliated to Leuconostoc mesenteroides, and sometimes Str. durans.

Lactic bacteria predominate in the microflora of the digestive tract of chicken and turkey. They are represented mainly by Lactobacillus acidophilus, L. salivarius, L. fermentum and L. buchneri. Streptococcus faecium is always isolated. L. ruminis, L. vitulinus, L. delbrueckii, L. coryniformis and L. viridescens were found in this ecological niche for the first time. S. faecium and S. faecalis prevail in the digestive tract of geese and ducks, while lactobacilli are detected in a lesser amount and are represented mainly by L. plantarum. L. salivarius cells isolated from the digestive tract of poultry are highly polymorphous. Most of the lactic acid bacteria found in the digestive tract of poultry can grow at 45-50 degrees C whatever is the species they belong to.

Normal microflora in the intestinal tract of fishes inhabiting fresh-water reservoirs includes lactic bacteria. The number of the bacteria depends on the animal species, the composition of food, the age, and the season. The highest number of these microorganisms (hundreds of millions per gram of the intestinal content) is found in carps. Enterococci are most often encountered in fishes inhabiting ponds: Streptococcus faecalis Andrewes a. Horder, Str. faecium Orla-Jensen, Str. bovis Orla-Jensen. Lactobacilli are more typical of fishes in water reserviors: Lactobacillus plantarum (Orla-Jensen) Bergey et al., L. casei (Orla-Jensen) Hansen a. Lessel, L. casei var. casei, L. casei var. rhamnosus, L. Casei var. alactosus, L. leichmannii (Henneberg) Bergey et al., L. acidophillus (Moro) Hansen a. Mocquot, L. Fermenti Beijerinck, L. cellobiosus Rogosa et al., L. Buchneri (Henneberg) Bergey et al. The content of lactic bacteria varies in water reservoirs; their highest content is found in ooze (tens of thousands per gram).