[Dynamics of microsymbiocenoses of upper respiratory tract in normal state and in pathology]

AIM

Study of features of interaction of bacteria in microsymbiocenoses of upper respiratory tract in dynamics in individuals with various state of health: healthy individuals, individuals after tonsillitis and bacteria carriers.

MATERIALS AND METHODS

Modification of pathogenicity factors (hemolytic, lecitovitellase, lysozyme and anti-lysozyme activity) in intermicrobial interactions of 226 strains of microorganisms isolated during quintuple analysis of upper respiratory tract biocenoses of examined individuals was studied. A hierarchical structure of each microbiocenosis was built based on the data obtained, and its temporal dynamics evaluated.

RESULTS

Microbial composition of mucous membrane of tonsils was more constant independent of state of health when compared with the nasal cavity. Normoflora that does not influence expression of pathogenicity factors and symbiont persistence was predominate and persisted for a long period in healthy individuals and bacteria carriers, whereas in individuals after tonsillitis opportunistic strains with a high communicative activity (leaders) that increase symbiont pathogenicity persisted for a long time.

CONCLUSION

The revealed differences in biocenoses dynamics of 2 biotopes of upper respiratory tract in healthy individuals, bacteria carriers and individuals after tonsillitis may be used to forecast stable health and development of dysbiotic disorders.

[Mechanisms of bacteria translocation in generalized chronic parodontitis]

Peculiarities of behavior reactions of bacteria-symbionts created conditions for the selection of translocators-strains. In microsymbiocenosis of parodontal pockets, from which translocation of bacteria into the blood was observed, the number of signals from intermicrobial communication, inhibiting the expression of the factors of colonization, virulence and persistence, was decreasing. Meanwhile, the number of signals on the increase of the expression of the factors given was increased. In 75% of cases strains-translocators were leaders; they gave more often signals on the inhibition of the growth of other strains-symbionts.

[Characteristics of microbiocenosis of gingival pocket in patients with chronic generalized periodontitis]

As a result of examination of 56 patients with chronic generalized periodontitis (CGP) of a moderate severity and a severe form of the disease, microflora from gingival pocket in patients which severe form of CGP was established to have higher specific weight in index of dissemination of strains such as Staphylococcus aureus, Streptococcus pyogencs, Enterococcus, Corynebacterium spp., anaerobic bacteria. Strains from patients with a severe form of CGP were characterized by a higher level of expression of the factors of pathogenicity and persistence. Associations of streptococci and staphylococci which the representatives of anaerobic flora such as Bacteroides, Fusobacterium, Prevotella, Clostridium, Peptostreptococcus were more often revealed in patients with a severe form of CGP. Fact of microbial translocation from the gingival pocket was established: from the blood of the patients with CGP of a severe form, strains-translocants were cultivated by 4 times more frequently than from the patients with CGP of a moderate severity.

[Modification of antibiotic resistance in microbial symbiosis]

In antibiotic therapy it is necessary to use drugs active against the pathogen in its association with the host normal microflora. The aim of the study was to investigate modification of antibiotic resistance under conditions of the pathogen association with the representatives of the host normal microflora and to develop the microbiological criteria for determining effectiveness of antibacterials. Modification of microbial antibiotic resistance was investigated in 408 associations. Various changes in the antibiotic resistance of the strains were revealed: synergism, antagonism and indifference. On the basis of the results it was concluded that in the choice of the antibiotic active against Staphylococcus aureus and Streptococcus pyogenes the preference should be given to oxacillin, gentamicin and levomycetin, since the resistance of the pathogens to these antibiotics under the association conditions did not increase, which could contribute to their destruction, whereas the resistance of the normoflora increased or did not change, which was important for its retention in the biocenosis. The data on changeability of the antibiotic resistance of the microbial strains under the association conditions made it possible to develop microbiological criteria for determining effectiveness of antibiotics in the treatment of inflammatory diseases of microbial etiology (RF Patent No. 2231554).

[Study of nasal and tonsillar mucosal microbiocenoses as one of the health indices]

The qualitative and quantitative compositions of nasal and tonsillar mucosal biocenoses were studied in healthy individuals and patients with chronic tonsillitis as an ecological criterion for assessing the stability of biocenosis and human health. The qualitative composition of tonsillar mucosal biocenosis turned out to be steady-state both in health and disease. The human nasal mucosa showed itself as an indicator system. Staphylococcal strains with a high persistent potential and polyantibiotic resistance, which may cause an exacerbation of the inflammatory process on translocation to the tonsillar mucosa, were selected on the nasal mucosa of patients with chronic tonsillitis.

[Biological characteristics of translocating bacteria during experimental otitis media]

AIM

To study dynamics of species composition, factors of pathogenicity and persistence, index of microbial load by bacteria translocating to tympanic cavity from nasal cavity.

MATERIALS AND METHODS

Translocation of bacteria was reproduced on the model of experimental staphylococcal purulent otitis media in 22 adult rabbits from "chinchilla" breed. Identification of translocating strains was performed by radioisotope label. Microflora of nasopharynx and middle ear was studied on day 4, 6, 10, 20, 30, and 180 after inoculation.

RESULTS

Translocating strains differed from nontranslocating by higher level of antilysozyme activity (> or =3 mcg/ml) and higher proportion of their microbial load in total index of microbial load of source biotope (> or =5%). During unfavorable course of otitis, increase of pathogenicity of strains-translocants in circumstances of microbial interaction was observed.

CONCLUSION

One of the mechanisms for the development of otitis media is translocation of indigenous bacteria and their associates to the inflammation site in middle ear where microbial interactions determine the outcome of infection. Results of experimental studies allowed to develop the method for prediction of otitis media course.

[Structural and functional characteristics of human microsymbiocenosis]

AIM

To study hierarchical structure of microbial microbiocenosis in tonsils accounting for the behavioral reactions of bacteria.

MATERIALS AND METHODS

Intermicrobial interactions in 100 biocenosis on the surface of tonsillar mucosa were studied in healthy persons, carriers of bacteria and patients with chronic tonsillitis. Number of commands made by symbionts and directions of commands for modification (suppression, upregulation) of pathogenicity factors (hemolytic, lecitovitellase, lysozyme, and antilysozyme activity) was studied.

RESULTS

On the basis of cluster analysis of functional activity of symbionts 3 equations were created. Equation 1, which included total number of commands issued by each symbiont and their significance for expression of pathogenicity factors, allowed to differentiate of symbionts on dominants and associates. Equation 2, which included directions of commands issued by dominants and associates, allowed to give preliminary prognosis for biocenosis: predominance of commands for suppression of pathogenicity factors points to good prognosis for biocenosis, whereas whereas predominance of commands upregulating pathogenicity factors predicted the unfavorable prognosis. The final prognosis for the biocenosis was determined using equation 3 calculating coefficient of biocenosis' functional state (ratio of total number of commands for upregulation of pathogenicity factors to total number of commands for their suppression).

CONCLUSION

Proposed methodical key for structural and functional assessment of biotope microsymbiocenoses is universal and could be used for prognosis of host's health.

[Mechanisms of interaction of associative symbionts during viral-bacterial infections]

Literature data about mechanisms of interaction between viruses and bacteria in circumstances of associative symbiosis are summarized. Interactions of influenza viruses, adenoviruses, Coxsackie viruses with different taxons of pathogenic and opportunistic bacteria are showed. Influence of these interactions on pathogenicity factors of viruses and bacteria is multidirectional (induction, suppression) which could determine the course of infectious process.

[Interaction between bacteria and erythrocytes and their role in the development of infectious anaemia]

The concentration of hemoglobin in blood of patients with pyoinflammatory diseases was shown to depend on the ability of bacteria to interact with erythrocytes. Bacteria with high hemolytic activity (> or = 70% hemolysis) and anti-hemoglobin activity (>3 g/1) were isolated from pyoinflammatory foci of patients suffering from anaemia. Structural changes were investigated in vitro and in vivo erythrocytes in terms of their interaction with microorganisms by electron microscopy. For the first time, the phenomenon of coccal location within erythrocytes was established. Staphylococci with a high level of hemolytic and anti-hemoglobin activity appear to survive and multiply within erythrocytes that results in destroying hemoglobin. Staphylococci with a low level of mentioned activities are subjected to destructive changes within erythrocytes and subsequent killing.

[The role of persistence and virulence factors in microecological changes in a humans]

The patterns of persistence and virulence factors expression in the representatives of human microbial biocenosis depends on a complex of the environmental conditions: influence of microbes-symbionts, biotope peculiarities, properties of microorganisms located within eukaryotes. Interactions of symbionts in pairs "indigen-indigen" isolated from mucous membrane of tonsils in healthy persons, did not lead to changes in expression of pathogenic properties. Interinfluence in pairs "pathogen-indigen" and "indigen-indigen", isolated from patients with chronic tonsilitis were accompanied by an increase of anti-lysozyme, hemolytic and lecithovitellase activities. Migration of strains of non-enzymatized gram-negative bacteria (NEYNB) from nasal into tympanic cavity in experimental acute purulent otitis is connected with an earlier increase of their number in the nasal cavity and the expression of anti-lysozyme activity. In acute and chronic pyoderma, expression of ALA is more marked in bacteria from a perifocal damage in contrast to focal damage of normal skin. In conditions of interaction between erythrocytes and staphylococcal clones with different levels of expression of pathogenic factors, differences were observed in dynamics of hemolytic and anti-hemoglobin activities.

[Interaction of bacteria and red blood cells]

The interaction of staphylococci, streptococci, meningococci, enterobacteria, leptospires and other microorganisms with red blood cells is considered. Three forms of the interaction of bacteria and red blood cells are discussed: adhesion, the influence of secretory factors on red blood cells, the action of pathogenic bacteria on hemoglobin. The applied aspects of the interaction of bacteria and red blood cells in the human body are presented in accordance with the results of clinical and laboratory studies.

[Effect of medicinal plants on the antilysozyme activity of microorganisms]

Medicinal plants effect on antilysozyme activity of E. coli, Klebsiella, S. aureus, Candida, Bifidobacterium, Bacteroides, Clostridium was evaluated in vitro. It was demonstrated that the effects differed substancially according to the microorganism taxonomy. The experimental data on the plants inhibitory activity may be used for elaboration of effective regimes of infections and disbiosis treatment.

[Clinical importance of infective agent persistence in Salmonella infection in children]

The persistence properties of 70 S. enteriditis cultures and 12 S. typhimurium cultures isolated from the feces of children of the earliest age groups with the gastrointestinal form of Salmonellosis infection were studied. The study revealed that the low level of persistence properties occurred in most cases of mild forms of the disease. Salmonellae with a high level of anticomplement and antilysozyme activity were more often isolated in cases of moderate and severe forms of salmonellosis. The presence of correlation between the expression of the factors under study and the severity of the symptoms of intoxication in combination with the duration of the diarrhea syndrome in moderate and severe forms of Salmonella infection in children of the earliest age groups was established. The suggestion was made that the evaluation of the persistence properties of bacteria may be used for the prognosis of the course of the infectious process.

[Bacterial interactions]

The review deals with specific features of interactions in microbial biocenoses. The subdivision of the mechanisms of microbial interactions in associations into direct and indirect ones is proposed. The formation of intercellular contacts and matrix belongs to one group of mechanisms, the second group includes the products of metabolism (changes in the physical and chemical composition of the medium, specific growth regulators) and secreted factors (antibacterial substances, pheromones and signal molecules, vitamins, specific mediators). The applied aspects of the knowledge of microbial interactions in the human body are presented.

[Effect of gastrointestinal tract secretions on the anti-lysozyme activity of enterobacteria]

The effect of the duodenal contents and its components on the antilysozyme activity (ALA) of enterobacteria was studied. Under the action of native bile and the preparation of dried bile the stimulation of the expression of ALA factor in 86.6-93.3% of enterobacteria was observed. Pancreatin increased the level of the secretion of ALA factor by 50% in comparison with the control. The preparation of egg lysozyme produced no changes in the frequency and level of the expression of ALA factor. The study revealed the dose-dependant character of the action of duodenal contents: in the native form, as well as at concentrations of 50% and 25%, duodenal contents stimulated the expression of the ALA factor of enterobacteria; at concentrations of 12.5% and lower, its effect could be stimulating, inhibitory or neutral.

[Prognostic value of isolation of L-forms of Mycobacterium tuberculosis]

A procedure has been developed to detect antilysozymatic activity n L forms of Mycobacterium tuberculosis (MBT). A mode of predicting the course of a tuberculosis process in the lungs by the degree of antilysozymatic activity of MBT is outlined. Thus, when the level is 4 micrograms/ml or higher, progression or exacerbation of tuberculosis is predicted, when that of 0-3 micrograms/ml, a good prognosis is expected.

[Microbial biocenosis of the nasal mucosa in healthy persons and in Staphylococcus carriers]

The normal microflora of the nasal mucosa in man is differentiated into main, complementary and casual microflora, taking into account its isolation rate and characteristics of microbial contamination. The main microflora of adults, in contrast to children, is represented, in addition to coagulaso-negative (CN) staphylococci, by bacteria of the genus Corynebacterium. In staphylococcal carrier state a decrease in the isolation rate and the amount of bacteria belonging to the main and complementary microflora (CN staphylococci, Micrococcus, Streptococcus, Bacillus) was observed. Moreover, in carriers the weakening of the degree of association between CN staphylococci, Micrococcus, Corynebacterium, Streptococcus in symbiotic pairs was noted. In the absence of S. aureus carrier state the main and complementary microflora was characterized by the combination of the factors of antagonism and persistence, while in carrier state the complex of colonization factors was defective in the main microflora and well pronounced in coagulase-positive staphylococcal strains and enterobacteria.

[Microbial biocenosis in the mucous membranes of the nose and the middle ear in patients with purulent otitis]

25 biocenoses of the microflora of the mucous membranes of the nose and the middle ear in patients having acute and chronic purulent otitis media (epi- and mesotympanitis) were studied. The dynamic study was carried out at the peak of the manifestations of clinical symptoms and on convalescence or improvement of the state of patients. In the process of convalescence the normalization of the composition of the microflora of the nose and the middle ear was found to occur in patients having acute otitis as compared with those having chronic otitis. In chronic otitis dysbiosis was observed in the microflora of the nose and the middle ear (the preservation of Staphylococcus aureus and enterobacterial strains with increased capacity for persistence). Correlation between the taxonomic composition and the biological properties of the microflora of the nose and the middle ear was established. Changes in the properties of individual strains of the microflora in the bacterial interaction of symbionts were more pronounced in the acute form of otitis than in the chronic one.

[Some features of tonsillar microflora and microbial interaction (in normal and pathological states)]

The description of a new method for the determination of interaction between bacterial strains isolated from the mucous membrane of tonsils of healthy children and patients with chronic tonsillitis. In the analysis of mutual influence of symbionts on the hemolytic, lecitovitellase, lysozyme and antilysozyme activity of microbes isolated from healthy children no changes in the expression of these pathogenicity and persistence factors have been detected in the overwhelming majority of cases (70.8-89.9%). In the microflora of sick children interactions were synergic with respect to pathogenicity factors in 35.2-46.7% of cases and antagonistic in 18.7-31.3% of cases.

[The antilysozyme activity of Mycobacterium tuberculosis L forms]

The method for the detection of antilysozyme activity (ALA) in M. tuberculosis L forms was developed. The level of ALA in M. tuberculosis L forms isolated from patients with different clinical forms of the disease varied within 1-5 micrograms. M. tuberculosis L forms with the ALA level > 4 micrograms were isolated from patients with the progressing course of the disease. The method for the prognostication of the course of the tuberculous process in the lungs by the results of the antilysozyme test was proposed.

[Hygienic evaluation of staphylococcal nasal mucosal biocenosis in school children of an industrial city]

The results of microbiological spatial monitoring in Orenburg were evaluated. A biological variety of Staphylococcus on the nasal mucosa of schoolchildren were detected. The highest proportion of carriage of the pathogen Staphylococcus was found in different districts of Orenburg, which had the highest air pollution.

[The role of persistence factors in the forming of a microbial biocenosis in the nasal mucosa in staphylococcal bacteria carriers]

The microbial biocenosis of the nasal mucosa under normal conditions and in cases of Staphylococcus aureus carriership was studied, taking into account the biological properties of symbionts in 159 persons. In S. aureus carriers the dysbiotic state of the intranasal microflora was established: the decrease of the index of total microbial contamination, the index of contamination with obligate coccal microflora and the index of specific diversity. The factors of the persistence and antagonism of dysbiotic microflora contribute to the mechanism of the development of dysbiosis. In the biocenosis of the carriers obligate microflora strains (Corynebacterium, Micrococcus and coagulase-negative staphylococci) with more pronounced interspecific antagonism or bacteriocinogeny were dominant.

[The suppressive action of a magnetic-laser ray and of an electrolytic solution of sodium hypochlorite on the factors of causative agent persistence]

The suppressive action of a magnet-laser ray and electrolyzed sodium hypochlorite solution on the persistence factors (antilysozyme, "anti-interferon") of Staphylococcus aureus and Neisseria gonorrhoeae is shown. The optimum conditions (time, dose, concentration) for the regulation of the persistence properties of the pathogens has been determined. The use of physicochemical factors in the proposed parameters has been shown to be effective for the therapy of purulent inflammatory diseases and the sanitation of S.aureus carriers.

[The resident staphylococcal bacterial carriage in a human population as an index for the microecological monitoring of its habitat environment]

The informative character of staphylococcal persistence factors (antilysozyme and "anti-interferon" signs) as the indices of resident staphylococcal carrier state in the microecological monitoring of the aerial environment was determined. In areas, ecologically unfavorable with respect to the occurrence of diseases of respiratory organs and to the level of air pollution, staphylococcal strains with persistence factors were isolated from children 3 times as often as in areas with low levels of morbidity in respiratory diseases and environmental pollution. The background level resident staphylococcal carrier state was determined (8.1%), permitting the evaluation of the ecological loading and the mapping of the monitored territories.

[The characteristics of the formation of the staphylococcal landscape in the nasal mucosa of different types of bacterial carriers]

The complex study of factors of persistence, virulence and antagonism in 473 coagulase-positive (CP) staphylococci and 489 coagulase-negative (CN) staphylococci inhabiting the nasal mucosa of resident and transitory carriers, and not carriers of CP staphylococci, was made. In the selection of virulent strains of CP staphylococci the factor of anti-interferon activity seemed to be of greater importance than the factor of antilysozyme activity, but the latter was preferable in the selection of virulent strains of CN staphylococci. Biovars of CP staphylococci with a set of factors of persistence, virulence and antagonism were isolated from resident carriers 1.6-3.1 times more frequently than from transitory ones. The selection of virulent biovars could be made among strains of CN staphylococci with pronounced persistent properties, isolated from subjects carrying no CP staphylococci.

[Characteristics of antilysozyme activity of Staphylococcus aureus in various types of experimental infection course]

The connection between the level of Staphylococcus Aureus anti-lysozyme activity (ALA) and the character of the experimental infection course has been revealed. The subsiding type of infection was developed by infecting by clones with the low ALA and at the same time there was a shift in the structure of population at the final stage of infectious process to the reduction of its heterogeneity in respect of ALA and the preservation of the colonies only with the zero and low ALA. The protracted form of infection was provoked by the clone with the high ALA and the dynamics of microbial dissemination had rhythmical nature and a high heterogeneity in respect of ALA in the structure of population of staphylococcus was preserved and the selection of colonies with the high ALA was observed. ALA of staphylococcus is an important link of pathogenesis of persistence as it determines the duration and dynamics of the survival of the pathogen in the organism.

[The antilysozyme activity of meningococci]

The antilysozyme activity of 184 meningococcal strains was studied. Such activity was found in all strains within the range 1-25 micrograms/ml, which was due to the heterogeneity of bacterial population. Strains varying in the total level of their lysozyme activity differed in the population structure by this sign. Preparations inhibiting antilysozyme activity could be differentiated according to the character of their action by the method of the population analysis. In the process of phagocytosis the selection of clones with a high level of antilysozyme activity was found to occur. The antilysozyme factor, heat resistant protein with a molecular weight of 10,000-30,000 D, was sensitive to trypsin.

[Treatment of endometritis and salpingo-oophoritis monitored by the antilysozyme activity of the agents]

The authors suggest new methods for the choice of drugs and physiotherapeutic modalities for the treatment of female genital inflammations, based on the suppression of the agents' antilysozymic activities, factors of the agent intracellular persistence. Clinical trials of these methods in 91 patients have shown their high efficacy: the incidence of complete remissions has increased by 60.7%, incidence of disease recurrences reduced by 53%, and remission periods in chronic patients were prolonged by 2.5-3 times (from 0.5-1 year to 2.5-3 years).

[Experimental and clinical studies of drug regulation of the anti-lysozyme activity of microorganisms causing opportunistic infections]

Experimental materials on choosing antibiotics for etiotropic therapy of opportunistic infections with an account of the regulating effect of the drugs on the ++anti-lysozyme activity of pathogens (the factor of intracellular parasitism) are presented. The in vitro data were applied to the clinical trials in 30 patients with chronic and acute pyelonephritis of the Proteus etiology and to 25 patients with chronic inflammatory diseases of Staphylococcus etiology. It was shown that the use of the antibiotics which lowered the ++anti-lysozyme activity of microorganisms promoted a more rapid disappearance of the disease clinical signs, increased 2- to 3-fold the terms of the remission and resulted in an increase in the number of the persons with complete remission (54.5 to 63.6 per cent) as compared to the use of the drugs which stimulated the pathogen property or were indifferent to it.

[Biotyping of pathogenic cocci using mathematical methods]

The differential information content of biological signs in the ecology of different staphylococcal and streptococcal species has been studied by the mathematical method. The method for the intraspecific differentiation of staphylococci, streptococci and gonococci into pathovars with the use of programs for the computerized analysis of the material has been proposed. The mathematical models of strain virulence in different coccal species are described.

[Method of determining the antilysozyme activity of microorganisms]

The method for the determination of the antilysozyme activity of microorganisms is described. The method consists in the cultivation of the strains under study in a lysozyme-containing medium, and the effect of lysozyme inactivation is determined from the growth of Micrococcus luteu S indicator strain adjacent to active strains. The quantitative evaluation of this property is presented. The study of 1 296 strains belonging to 9 genera has disclosed that antilysozyme activity occurs most frequently among Gram-negative bacteria.

[Activation of student cognitive activities in the process of teaching medical microbiology]

The main trends of methodical work conducted at the chair of microbiology of Orenburng Medical Institute are presented. For the purpose of activation of cognition activity of students during medical microbiology teaching the following methods were applied: presentation of the teaching material, creation of visual teaching methods in a single methodical plan in accordance with the logic structure graphs of the subject as a whole, its individual sections and themes; introduction of problem teaching method, solution of practical tasks of the II and III learning level; introduction of scientific achievements of the chair into the teaching process. Result of evaluation of the efficacy of the teaching-methodical work of the chair carried out demonstrated that knowledge of the principal microbiology problems in the students and interns persisted for long periods of time.

[Lysozyme activity of pneumococci]

Examination of 329 pneumococcal strains showed that 41.2 per cent of the cultures had lysozyme activity. The frequency of the lysozyme feature depended on the method used. The lysozyme active strains were more frequently isolated from patients than from healthy persons and characterized by antibiotic resistance. The lysozyme feature correlated with the pneumococcal virulence with respect to albino mice, capacity for capsule formaiton and resistance to phagocytosis.

[Experimental study of the antimicrobial effect of lysozyme in combination with antibiotics]

A synergistic effect of the antibacterial action of the lysozyme combination with various antibiotics against gram-positive and gram-negative microorganisms was found. The intensifying effect of lysozyme on its combination with antibiotics was more evident with respect to gram-positive microbes and less evident with respect to gram-negative organisms. The combinations os lysozyme with methicillin, lincomycin, oleandomycin or erythromycin proved to be most active against staphylococci. A high synergistic effect against streptococci was observed with the use of the lysozyme combination with benzylpenicillin, morphocycline, oleandomycin, ceporin or monomycin. The combination of lysozyme with macrolides had a maximum inhibitory effect on Coli bacteria.

[Characteristics of the antimicrobial activity of lysozyme]

The antibacterial effect of lysozyme manufactured in the USSR was studied with respect to 1496 pathogenic strains of different microbial species. It was found that the percentage of the organisms sensitive to lysozyme among the total number of the microbes tested was not high and ranged within 1.5-3 except streptococci (21.7 per cent). Significant differences in the minimum bacteriostatic concentration (from 0.0006 to 10 mg/ml) with respect to both different microbial species and organisms belonging to the same microbial species were found. By the level of the antibacterial activity the Soviet lysozyme was not inferior to the Italian preparation. With respect to streptococci the Soviet lysozyme was more active.