[Antagonism of lactobacilli, oral streptococci and staphylococci].

From the oral cavity of healthy young people aged 18-22 years there were isolated 26 strains of lactobacilli, 28 streptococci, including the pathogenic and opportunistic strains, and 32 strains of staphylococci, 10 of which were methicillin-resistant S.aureus. Oral lactobacilli possessed by a high probiotic potential, showing high antagonism to methicillin-resistant staphylococci, pathogenic and opportunistic streptococci and enterococci. Oral lactobacilli showed medium and high adhesive activity that determines their high adaptive capacity. Staphylococci and streptococci in 90.3% of cases have not an antagonistic effect on lactobacilli. Isolated lactobacilli can be used as probiotic strains for oral administration.

[Microbiocenosis of major biotopes of the oral cavity in patients with tongue carcinoma during complex treatment].

The composition of the microflora in three biotopes of the oral cavity was examined in 36 patients with tongue carcinoma before chemotherapy, one - two weeks after two courses of chemotherapy and before gemiglosseklomiya. The oral dysbiosis was revealed in patients before antitumor therapy. The opportunistic and pathogenic bacteria in concentration more than 4 lg CFU/cm² were dominant in microbiocenosis of oral cavity. Most of the isolated microorganisms were capable of maintaining the inflammatory process by secreting oral enzymes and toxins. The microflora formed normobiocenosis in oral cavity after two courses of chemotherapy. The pathogenic potential of selected microflora in patients after preoperative radiotherapy before surgery was more pronounced than the microflora of healthy people, and also in patients prior to treatment. Dysbiosis of III degree was detected in oral cavity of patients with tongue carcinoma before gemiglosseklomiya. requiring correction for the prevention the postoperative complications.

[Oral microbiocenosis features of diabetic patients after orthopedic treatment with various types of crowns].

The article gives a detailed analysis of oral cavity microbiocenosis features of 36 patients with type II diabetes for 5 years. These data reflects microbiocenosis features before and after orthopedic treatment with metal-ceramic and pressed crowns. These results indicate that frequency of occurrence and the number of microorganisms of the genus Streptococcus, Staphylococcus (including S. aureus), Peptostreptococcus and Candida is significantly higher in patients after orthopedic treatment with pressed crowns than with metal-ceramic crowns. A high percentage of normal microflora, particularly lactobacilli (60%), was revealed on gingival mucosa in patients after orthopedic treatment with metal-ceramic crowns.

[Peculiarities of microbiological composition of oral fluid during various stages of orthodontic treatment in children and adolescents].

The article presents the results of analysis of spectrum, the rate of frequency and the amount of microorganisms in oral liquid before the beginning of orthodontic treatment of dental abnormalities and deformations and in its stages (6 and 12 months later). As the result of the study the appearance of pathologic microorganisms Staphylococcus aureus and a great number of conditionally-pathogenic fungi of Candida family and Porphyromonas spp. were determined. The obtained results show the need of elaboration of standards for the treatment of orthodontic patients.

[The microbiocenosis of intestine and immune status of children of primary school age].

The article deals with the study of species and quantitative structure of microbiocenosis of intestine and characteristics of immune status in children aged 8-10 years. In children with chronic tonsillitis pharyngitis and bronchitis and with diseases of gastro-intestinal tract (biliary dysfunction, chronic gastroduodenitis and gastritis) the microbe imbalance of various degree of manifestation was established which was prevailing in cases of children with pathology of gastrointestinal tract. The increase of quantity of opportunistic microflora induces the production of both immunoglobulins and cytotoxic lymphocytes and cells-natural killers.

[The disbiotic changes of intestines microflora in healthy people].

The article presents the results of study of species and quantitative composition of intestinal flora in volunteer students aged 18-21 years. The disbiotic abnormality of different degrees was diagnosed in 75% of students. The associations of microorganisms, in case of normobiosis and disbacteriosis degree I included predominantly representatives of normoflora, in case of disbiotic abnormality II and III degrees included both representatives of normoflora and opportunistic pathogenic microorganisms.

[Spring water quality assessment regarding the problem of endemic fluorosis].

A possible variant for reducing the consumption of fluoride by population of Tver region is the use of water with low fluoride content, such as spring water. Assessment of drinking suitability of spring water (the content of physiologically important mineral elements and microbial purity) is relevant to our region. Water samples from 6 spring-water source of Tver region were studied during the year. The content of fluoride and calcium were measured by using an ion-selective electrodes. Microbiological purity tested by the presence of total coliform bacteria, thermotolerant coliform bacteria, coliphages and total microbial numbers. The analysis of some mineral components in spring water of Tver region showed that calcium content was in range 33-88 mg/l, that satisfied the recommended value; fluoride concentration is less then 0.5 mg/l. In all spring water samples total coliforms, thermotolerant coliforms and coliphages were absent. The total microbial number was in standard range, except of two spring-water source in the autumn and summer. The data suppose that spring water of Tver region can be used as a component of diet normalizing the fluoride consumption at risk of dental fluorosis in children.

[Biofilm formation by antagonistic strains of oral Lactobacillus].

Highantagonistic strains of lactobacillus isolated from the oral cavity of healthy people, genetically identified as L. fermentum 39, L. rhamnosus 50, L. rhamnosus 24, showed high degree of autoaggregation, surface hydrophobicity, coaggregation, adhesion, and the ability to form biofilms. These strains can be used to create new probiotic drugs for the prevention and correction the dysbiosis of the oral cavity.

[Clinical effect of chitosan in bacterial vaginosis therapy].

AIM: Determination of antibacterial activity of acid-soluble chitosan in bacterial vaginosis therapy in women of reproductive age and comparison of therapy results of traditional scheme and local administration of acid-soluble chitosan. MATERIALS AND METHODS: Vaginal microflora of 76 gynecologic and obstetrical female patients (18-43 years of age) with bacterial vaginosis diagnosis was examined by using bacteriological method. Control group consisted of 30 practically healthy women. Sensitivity of 145 bacteria strains from 14 genera to 2% acid-soluble chitosan solution (200-250 kDa molecularweight) was determined by using agar diffusion method. RESULTS: During bacterial vaginosis members of the Gardnerella, Mobiluncus and Bacteroides genera dominated with a background reduction of lactobacilli quantity. An increase of population level of Staphylococcus, Enterococcus, Prevotella, Porphyromonas, Peptostreptococcus genera members, and Candida species was also observed. All the microorganisms were sensitive to 2% chitosan solution. Mycoplasma and Ureaplasma spp. were sensitive to chitosan in 82% of cases. Administration of chitosan in local therapy of vaginosis resulted in suppression of opportunistic microflora and clinical effect with a lack of adverse effects. CONCLUSION: Local administration of chitosan is perspective against bacterial vaginosis.

[Antibacterial activity of nanostructured silver gel].

AIM: Evaluation of antimicrobial activity of L-cysteine silver gel against various species of pathogenic and opportunistic microorganisms. MATERIALS AND METHODS: Antibacterial activity of L-cysteine silvergel with silver concentration from 1.28 x 10(-3) to 3.75 x10(-3) mole/l was studied by using agar diffusion test. Reparation processes were determined experimentally in 102 male Wistar rats (150 g) by forming under ether anesthesia a 225 mm2 skin wound on the back surface of the body and by introducing virulent strain Staphylococcus aureus 236 24-hour suspension (10(6) CFU/ml) inside the wound. The rat wounds were treated with L-cysteine silver gel once per day for one week and proliferation processes were studied on day 7, 14 and 21. RESULTS: Antibacterial activity of L-cysteine silver gel was detected against test strains: S. aureus ATCC 25923; Bacillus subtilis 537; Escherichia coli ATCC 25922; Shigella sonnei 1908; Pseudomonas aeruginosa ATCC 27853; Salmonella typhimurium 5715 and Candida albicans ATCC 885-653. Mean period of wound healing was reduced by 3 days when L-cysteine silver gel was used, index of healing acceleration was approximately 20%. CONCLUSION: L-cysteine silver gel has antibacterial and wound healing properties, it can be used for the creation of new medical preparations.

[Genetic identification and study of the ability of lactobacilli isolated from the oral cavity of healthy individuals to form biofilms].

The highly antagonistic lactobacillus strains isolated from the oral cavity of human individuals were genetically passported as L. fermentum 39, L. rhamnosus 50, and L. rhamnosus 24, by applying the RAPD-PCR technique with two types of primers (M13, MSP). These lactobacillus strains showed high degrees of autoaggregation, surface hydrophobicity, coaggregation, and adhesion. These characteristics determine the obvious capacity of lactobacilli to form biofilms, which may be used to design new probiotic agents.

[Ability of human oral cavity indigenous lactobacilli to form biofilms].

AIM: To determine ability of lactobacilli strains indigenous for oral cavity of healthy persons to adhesion, autoaggregation, surface hydrophobicity, coaggregation and formation of biofilms. MATERIALS AND METHODS: Twenty-three anatagonistically active isolates of lactobacilli, including 5 strains of Lactobacillus plantarum, 6--L. rhamnosus, 4--L. paracasei, and 8--L. fermentum, were studied. Characteristics of lactobacilli associated with adhesion, autoaggregation, surface hydrophobicity, coaggregation, and formation of biofilms were determined. RESULTS: Bacteria were characterized by high and intermediate level of adhesion, autoaggregation, surface hydrophobicity, expressed ability to form biofilms and different coaggregation activity relative to test-strains Staphylococcus aureus, Escherichia coli, Candida albicans, Pseudomonas aeruginosa, and Bacillus subtilis. CONCLUSION: Studied characteristics of lactobacilli could be used for development of new probiotics aimed at stabilization of oral cavity normoflora.

[Genetic identification of antagonistically active lactobacillus strains isolated from the oral cavity of healthy individuals].

Examination of dental deposits from 45 healthy individuals detected 3 lactobacillus strains showing a high antagonism toward test cultures. The api 50 CH "bio Merieux" test systems were employed to identify strains as Lactobacillus fermentum 39, Lactobacillus rhamnosus 24 and Lactobacillus paracasei 50. The results of analyzing the sequences of the 16S rRNA genes of the test strains confirmed this identification, except for the latter strain. The taxonomic status of the third strain L. rhamnosus 50 was determined by the bioinformative analysis of the nucleotide sequence of the 16S rRNA genes.

[Oral cavity microbiocenose in healthy teenagers and patients with chronic gastritis and gastroduodenitis].

Microbial association distinctive features and colonization degree of different oral cavity biotope were established in healthy teenagers and patients with chronic gastritis and gastroduodenitis. There were studied mucous membrane surfaces of cheek, tongue, content of gingival crevice, oral fluid and dental plaque of 24 healthy persons of the age 12-17 years and 29 patients of the same age with gastritis and gastroduodenitis. On the mucous membranes of the ill teenagers there were found Porphiromonas type bacteria, 20% more Staphylococcus, 90% less Peptostreptococcus, 30% less Lactobacillus, 20% less Veillonella and Stomatococcus. In saliva anaerobic Peptostreptococcus and facultative anaerobic Streptococcus (7 lg COE/ml); Porphiromonas, Veillonella, Peptococcus and Staphylococcus (6 lg COE/ml); Neisseria (5 lg COE/ml); Stomatococcus, Enterobacteriaceae and Bacillus (4.6 lg COE/ml); Lactobacillus and Candida (4 lg COE/ml) predominated. In patients with chronic pathology in all tested biotopes there was found the increase of the whole microbiota spectra (representatives of opportunistic pathogenic microfiora were detected more often) as well as the bacteria number if compared with healthy teenagers.

[Sensitivity to antibiotics monitoring of oral microflora in practically sound children and patients with chronic gastroduodenitis].

Characteristic of oral microflora in practically sound children and patients with chronic gastroduodenitis was offered. Microflora singled out from ill persons differed by pathogenicity in previously opportunistic pathogenic forms. Monitoring of sensitivity and resistivity to antibiotics of the singled out microflora in practically sound children and ill with chronic gastroduodenitis was presented. When treating oral diseases one should take into account the high resistivity to antibiotics (especially to benzilpenicillin) of opportunistic pathogenic forms.

[Microflora of gastrointestinal tract in patients with chronic cholecystitis].

AIM: Assessment of quantitative and qualitative characteristics of gastrointestinal microflora in patients with chronic cholecystitis. MATERIALS AND METHODS: Bacteriological analysis of biopsy samples of esophageal and gastric mucosae as well as stool samples was performed in 10 healthy volunteers and 28 patients with chronic cholecystitis. RESULTS: Opportunistic microorganisms are acquiring greater significance in formation of gastrointestinal microbiocenosis. Significant increase of both isolation rate and density of gastrointestinal tract colonization by staphylococci, enterobacteriae and anaerobic microorganisms was revealed. CONCLUSION: Obtained results showed abnormalities of microbiocenosis of esophageal and gastric mucosae and presence of intestinal disbacteriosis of different degrees of intensity.

[Oral cavity microbiocenosis in healthy adolescents and patients with chronic gastroduodenitis].

AIM: To determine characteristics of microbial associations and degree of oral cavity colonization by different biotopes in healthy adolescents and patients with chronic gastroduodenitis. MATERIALS AND METHODS: Saliva, dental deposit, content of tooth-gingival cavity and material from buccal and lingual mucous surfaces of 24 healthy adolescents and 29 patients of the same age with gastroduodenitis were used for bacteriological analysis. Inoculation were made on the following growth media: yolk-salt agar, Endo, Saburo, MRS as well as on Columbia and Saedler blood agars. RESULTS: It was shown that rate of isolation of peptostreptococci from oral cavity of patients was 90% lower compared with controls; rate of isolation of lactobacilli, Veillonella, and stomatococci was 30% lower, whereas hemolytic Porphyromonas, staphylococci and streptococci were isolated 20% more frequently. Concentration of peptostreptococci and streptococci was 7.0 lg CFU/ml, whereas concentration of Porphyromonas, Veillonella, peptococci and staphylococci was 6.0 lg CFU/ml, Neisseria--5.0 lg CFU/ml, stomatococci, bacilli and Candida fungi --4.5 lg CFU/ml. Decrease of concentration of lactobacilli to 4.0 lg CFU/ml was noted. CONCLUSION: Compared with healthy group of children, widened spectrum of microorganisms in all studied biotopes of oral cavity was observed in patients with chronic gastroduodenitis; species belonging to pathogenic microflora were detected in patients more frequently and in more quantities.

[Screening of nonpathogenic strains of Enterococcus faecium with antagonistic activity].

Forty two strains of enterococci were isolated from feces of healthy adolescents. Strains were selected according to their antagonistic effects associated with bacteriocinogenic and microcinogenic activity. Resistance of enterococci to antibiotics, various concentrations of hydrochloric acid and bile, their level of production of organic acids and adhesiveness were determined. Characteristics related to pathogenicity were investigared in 5 microcinogenic strains of E. faecium with broad spectrum of antagonistic activity. Non-pathogenic microcin-producing strains of E. faecium resistant to physiological concentrations of hydrochloric acid and bile with broad spectrum of antagonistic activity against obligatory pathogenic and opportunistic microorganisms can be considered as possessing probiotic activity.

[Bacteriocinogenic highly antagonistic strains of lactobacilli].

Ability to secrete bacteriocines and microcines was studied in 25 cultures of lactobacilli isolated from intestine of healthy children. Sixteen (64%) of them produced microcines with wide spectrum of antagonistic activity. Susceptibility of microcines-secreting cultures to antibacterial preparations, different dilutions of hydrochloric acid and bile was studied along with their acid-producing ability. Five strains without DNA-se, RNA-se, gelatinase, lecitinase and caseinolytic activity were selected from Sixteen microcines-producing cultures. Three of the selected strains carried plasmid DNA and two didn't have plasmids. Bacteria were characterized by tolerance to hydrochloric acid and bile - minimal inhibitory concentrations for them were 1,25 and 10% respectively. Strains without plasmids were susceptible to majority of wide-spectrum antibiotics and resistant to fluorochinolones. Microcines-producing lactobacilli with wide spectrum of antagonistic activity against pathogenic and conditionally pathogenic microorganisms and tolerance to physiological concentrations of hydrochloric acid and bile have a potential to be used in manufacturing of probiotics.