Bacterial and Protozoan Lipoxygenases Could be Involved in Cell-to-Cell Signaling and Immune Response Suppression.

Lipoxygenases are found in animals, plants, and fungi, where they are involved in a wide range of cell-to-cell signaling processes. The presence of lipoxygenases in a number of bacteria and protozoa has been also established, but their biological significance remains poorly understood. Several hypothetical functions of lipoxygenases in bacteria and protozoa have been suggested without experimental validation. The objective of our study was evaluating the functions of bacterial and protozoan lipoxygenases by evolutionary and taxonomic analysis using bioinformatics tools. Lipoxygenase sequences were identified and examined using BLAST, followed by analysis of constructed phylogenetic trees and networks. Our results support the theory on the involvement of lipoxygenases in the formation of multicellular structures by microorganisms and their possible evolutionary significance in the emergence of multicellularity. Furthermore, we observed association of lipoxygenases with the suppression of host immune response by parasitic and symbiotic bacteria including dangerous opportunistic pathogens.

[Variations of oral fluid microbiota in healthy children and adolescents]. / Varianty mikroflory rotovoi zhidkosti u prakticheski zdorovykh detei i podrostkov.

The aim of the study was to establish the bacterial and viral associations of saliva and the immune resistance in 127 healthy people of different ages. The analysis sorted out three variants of oral fluid microbiota differing by certain combination of indigenous and facultative microflora. It was found that with age there is a significant increase in the number of adolescents with the third variant of the microbiota, characterized by a decrease in the number of indigenous microflora and increase in opportunistic microorganisms and viruses. With an increase in microecological shifts a tendency to decrease the level of lysozyme, an increase in the number of secretory IgA, accompanied by a decrease in antibody was revealed. It has been shown that bacterial and viral component of the microbiota of the oral fluid are in a dynamic relationship with each other, as well as immune resistance and can serve as an indicator of the health level and the selection criteria at the stages of clinical examination of children and adolescents, with the risk of dental disease.

MICROBIOCENOSIS OF THE ORAL CAVITY AS A REFLECTION OF INTESTINAL MICROBIOTA.

AIM: Determine qualitative and quantitative parameters of mouth and intestines microbiocenosis of healthy people in the age aspect to assess the status of the digestive tract microbiota, as an indicator of human health. MATERIALS AND METHODS: We examined 74 healthy subjects aged 12-18 years who have a comparative aspect investigated qualitative and quantitative composition of the oral fluid and feces microflora. RESULTS: The mouth and intestines microbiota of healthy people has a number of interrelated characteristics defined microbiota of the entire digestive tract The first time were described three variants of the mouth and intestines microbiota, characterized by a certain combination of obligate and facultasive microflora, depending on the age and livelihoods. CONCLUSION: Definition ofmouth and intestines microbiocenosis can be used to assess the status of the digestive tract microbiora as an indicator of health and correction of outlined features through a rational manner of life, balanced diet, pre-and probiorics administration.

[THE MICRO-ECOLOGY OF DIGESTIVE TRACT AS AN INDICATOR OF HUMAN HEALTH CONDITIONS].

The study was carried out to analyze qualitative and quantitative parameters of oral fluid and feces in 74 healthy individuals of different age groups. In most of the cases, alterations of micro-ecology are established characterizing by decreasing of amount of indigenous micro-flora and increasing of number of opportunistic pathogenic microorganisms of genera of Staphylococcus, Bacillus, Candida. The degree of evidence of these alterations reliably increases with age. It is established that microbiota, initial and terminal biotopes of digestive tract are closely interrelated and have number of common characteristics depending on age, hormonal and immune status and reflect conditions of micro-biocenosis of digestive tract in general. The character and degree of evidence of alterations of micro-biocenosis can be an effective diagnostic criterion for complex evaluation of human health conditions with following formation of risk groups in need of particular volume of correction activities.

[Microbiological monitoring of oral fluid of clinically healthy children].

The article presents qualitative and quantitative parameters of microbiocenosis of oral fluid and feces of clinically healthy children in different age groups. In most of the cases compensated disbiotic changes were found, which were characterized by reduction in the number of indigenous microflora (lactobacilli and bifidobacteria) and increase of representatives of opportunistic pathogens (Staphylococcus, Bacillus and Candida). Microecological changes in different gastrointestinal biotopes are closely interrelated. Saliva may be considered as a specimen of integral fluid of human environment and can be used for complex assessment of the state of gastrointestinal tract microflora.

[Role of viruses with oncogenic potential and their associations in oncogenesis in maxillofacial area].

The potential role of viruses with oncogenic potential such as human papilloma virus, cytomegalovirus, Epstein-Barr virus, herpes simplex virus type 1 and 2, herpes virus type 6, in the development of benign and pre-cancerous tumors of maxillofacial region was assessed in the study. We examined 26 patients with tumors in maxillofacial region (skin and mucosa) using molecular-genetic and histological studies of surgically removed neoplasms removed. In 53.8% of the examined samples DNA of Epstein-Barr virus, herpes virus type 6, herpes simplex virus type 1, or cytomegalovirus and in 35.7% of them the association of the above mentioned viruses were detected. It may confirm their relation with the development of benign, precancerous and malignant neoplasms in maxillofacial region.

[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.

[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.