[PHENOTYPICAL CHARACTERISTICS AND GENETICAL DETERMINANTS OF PATHOGENICITY OF STAPHYLOCOCCUS AUREUS, ISOLATED FROM BACTERIAL CARRIERS, RESIDING ON THE TERRITORIES WITH VARIOUS LEVELS OF ANTHROPOGENIC POLLUTION OF AIR ENVIRONMENT].

AIM: Comparative phenotypical and genetical evaluation of pathogenic potential of Staphylococcus aureus strains, isolated from resident bacterial carriers, residing on the territories with anthropogenic pollution of air environment of varying intensity. MATERIALS AND METHODS: S. aureus, isolated 3 times from mucous membrane of the anterior of nose from 210 children, were the object of the study. Anti-carnosine activity and biofilm formation was determined by a photometric method, antibiotics resistance--by a disc diffusion method. lukS, lukF, sec 3, clfA, clfB, agr and mecA gene detection, that are associated with S. aureus, was carried out by PCR. RESULTS: S. aureus strains, isolated from children, residing on the territories with a high level of anthropogenic pollution of air environment, were characterized by antibiotics resistance, higher values of anti-carnosine activity, 2 times more frequently formed biofilms with higher values of the parameter. clfA and clfB genes, that determine colonization of mucous membranes, and agr gene were detected in all the studied S. aureus strains, lukF and sec 3 genes were detected in 20-40% of the strains, isolated from children, residing on both territories. mecA and lukS genetical determinants were not detected. CONCLUSION: S. aureus, isolated from children, residing on the territories with high levels of anthropogenic pollution of air environment; were characterized by higher values of the studied factors of persistence and stability against antibiotics. Genetical determinants of pathogenicity were not detected in S. aureus, isolated from individuals, residing on both territories.

[Cycloferon biological activity characteristics].

AIM: Study the effect of cycloferon in experimental and clinical conditions on persistence properties of aurococci as well as features of their morpho-functional reaction by atomic force microscopy. MATERIALS AND METHODS: The study was carried out in 12 Staphylococcus aureus clones isolated from mucous membrane of nose anterior part of a resident carrier. The effect of cycloferon in vivo was evaluated in 26 resident staphylococci carriers under the control of anti-carnosine activity of staphylococci. Anti-carnosine activity was determined by O.V. Bukharin et al. (1999), biofilm formation -by G.A. O'Toole et al. (2000). Staphylococci treated with cycloferon were studied by atomic force microscopy in contact mode using scanning probe SMM-2000 microscope. RESULTS: The decrease of persistence properties of staphylococci under the effect of cycloferon in vitro and in vivo may be examined as one of the mechanisms of biological activity of the preparation. A significant increase of S. aureus surface roughness and changes in their morphology under the effect of cycloferon allow stating the disorder of barrier functions in the aurococci cell wall. CONCLUSION: The data obtained expand the understanding of cycloferon biological activity mechanisms.

[Structural and functional characteristics of betulin derivatives].

The effect of betulin derivatives on persistence properties of microorganisms was studied in vitro. It was shown that the antipersistence action of the betulin derivatives depended on their structure and the microbial species. The experimental data on the structure - function relation could be useful in development and synthesis of new agents for therapy of chronic infections associated with persistence of bacterial pathogens in macroorganism.

[Synthesis, modifications, and antimicrobial activity of the methylpiperazinyl amides of triterpenic acids].

N-Methylpiperazinyl amides of betulinic, platanic, glycyrrhetic, oleanolic, ursolic, and moronic acids were synthesized and modified. Betulin and betulonic acid showed antimicrobial activity against Staphylococcus aureus at a concentration of 90 mg/ml, and betulin manifested a bacteriostatic effect against Klebsiella pneumoniae at a concentration of 60 mg/ml. Among the studied N-methylpiperazinyl amides, the highest activity against S. aureus was observed for a betulonic acid derivative.

[Influence of synthetic antioxidants on persistence characteristics of microorganisms].

AIM: To assess antipersistence characteristics of synthetic antioxidants belonging to class of triterpenoids. MATERIALS AND METHODS: Synthetic antioxidants synthesized in the Institute of Organic Chemistry of Russian Academy of Science and belonging to class of triterpenoids were used in the study. Antioxidant activity of compounds was assessed by amperometric method using analyzer "TsvetYauza-AAA-01" ("Chimavtomatika Ltd.", Moscow) and expressed in quercetin units (QU). Influence of synthetic antioxidants on persistence characteristics (antilysozyme, anticomplement, and anticarnosine activities) of Klebsiella pneumoniae 278 (Tarasevitch State Institute of Standardization. and Control for Immunobiologic Preparations) and Staphylococcus aureus was determined by conventional methods. RESULTS: Antioxidant activity of studied compounds varied from 1.53 QU to 11.82 QU. Compound No. 5, which had maximal antioxidant activity and was characterized by presence of 2 atoms of oxygen and hydroxyl radical in its structure, influenced on expression of persistence characteristics of studied microorganisms most efficiently. CONCLUSION: Obtained results could be used for the development of new drugs aimed against persisting pathogens.

[Biological characteristics of microorganisms for prognosis of trophic ulcers course].

AIM: To substantiate the possibility to use the biological characteristics of microorganism, in particular, factors of its persistence, for assessment of severity of trophic ulcers of lower extremities. MATERIALS AND METHODS: Clinical examinations and bacteriological tests of 48 patients aged from 37 to 80 years with trophic ulcer of lower limbs were performed. Antilysozyme, anticomplement, anticarnosine as well as hemolytic activity of isolated microorganisms were assessed. RESULTS: It was established that microflora of trophic ulcers of lower limbs are diverse and microorganisms were isolated both in monoculture and in associations, with maximal significance of Staphylococcus aureus. Analysis of biological properties of microflora isolated in patients with various courses of trophic ulcers of lower limbs allowed to determine roles of antilysozyme, anticomplement, anticarnosine and hemolytic activities in severity of the illness. CONCLUSION: Performed studies allowed to develop diagnostic models for prediction of severity course of trophic ulcers of lower limbs.

[Effect of phytosubstances with antioxidant activity on persistence properties of microorganisms].

The in vitro effect of phytosubstances containing flavonoids and phenylpropanoids on the antilysozyme activity of varioous groups of microorganisms, such as staphylococci, bacilli, enterobacteria and nonfermenting bacteria was studied. The second fraction of the pink carbonic acid extract showed high antioxidant activity and most efficiently inhibited the ability of various microorganisms to inactivate the host lysozyme. The selected phytosubstance could be useful in clinical practice as an additional antimicrobial agent in etiotropic therapy or prophylaxis of some infections.