[The choice of antibiotic according the results of standard bacteriological analysis and express-method without isolation of pure cultures.]

The efficiency of choosing antibiotics using two methods was analyzed. The first method is based on standard laboratory analysis including isolation of pure cultures of prospective agent and detection of their individual sensitivity to antibiotics. The second method is based on a new express-technique permitting to simultaneously evaluate effect of pharmaceuticals on cultivated and not cultivated yet bacteria without isolation of pure cultures. At that, the second method permits to determine efficiency of antibiotics namely in those concentrations that can be made in the given nidus of infection. The study demonstrated existence of discrepancy between results obtained by using the given methods. The cause of discrepancy can be presence of not cultivated yet bacteria in pathologic sample. In favor of this assumption testify the received data concerning samples from patients where were presented a significant number of spore-former bacteria having additional mechanisms of resistance to antibiotics. Furthermore, the implemented study established antibiotics characterized by the greatest discrepancy of results obtained by applied methods that indicates the necessity of revision of schemes of implementation of start or empiric therapy.

Effects of Multicide, Antibacterial Drug, on Staphylococcus Biomembranes.

Drug penetration into bacterial biomembranes is one of the most important factors determining the efficiency of antibacterial therapy. Multicide, antibacterial drug, is a nanomolecule 1.3-2.0 nm in size, easily penetrating into staphylococcus biomembranes and causing rapid death of bacteria. The drug efficiency depends on its concentration and duration of exposure. Bacteria die as a result of cell wall perforation, which is associated with changes in its morphology and release of DNA from bacterial cell into the environment. Our results indicate the efficiency of primary damage to bacterial wall leading to elimination of biomembranes.

[The choice of antibiotic in microbiological analysis of phlegm.]

The efficiency of application of the test-system "Vy`borAntibiotika" (AntibioticChoice) in incubation of a maximal possible number of bacteria from pathologic material in case of pneumonia was studied. The results of meta-genome analysis permitted to establish that test-system support incubation of practically all bacteria detected in phlegm, including those attributed to so far non-incubated ones. The comparison of the results was carried out concerning a standard detection of sensitivity of bacteria to antibiotics and choice of efficient medicinal according the results of application of test-system "Vy`borAntibiotika". The obtained data demonstrates that test-system permits to choose antibiotic during 6-20 hours without isolation of pure strain.

[The choice of antibiotic in microbiological study of pyoinflammatory processes.]

The efficiency of application of test-system "Antibiotic Choice" was examined concerning evaluation of sensitivity to medications of maximal possible number of bacteria from pathological samples at burn trauma without isolation of pure culture. The results of metagenome analysis demonstrated that test-system permits supporting factually all bacteria discovered in wound discharge, including ones related to not cultivated yet. The comparison was carried out concerning results of standard identification of sensitivity of bacteria to antibiotics and efficient medication according the results of application of test-system "Antibiotic Choice". The obtained results demonstrate that test-system permits choosing antibiotic during 6-20 hours without separation of pure culture.

[CHOOSING ANTIBIOTIC IN MICROBIOLOGICAL ANALYSIS OF INFECTIONS OF URINARY EXCRETION SYSTEM].

The effectiveness of application of test-system "Choice of antibiotic" was evaluated as a tool for incubation of maximal amount of bacteria from pathological material under acute cystitis. The results of meta-genome analysis established that test-system permits supporting growth of practically all bacteria detected in urine, including ones relating to "uncultivated for the present". The comparison of results of standard detection of sensitivity of bacteria to antibiotics and identification of effective pharmaceutical according the results of application of test-system "Choice of antibiotic" as well was implemented It is demonstrated that test- system permits choosing antibiotic during 6-20 hours wiihout isolation of pure strain.

Optimization of the Protocol for the Isolation and Refolding of the Extracellular Domain of HER2 Expressed in Escherichia coli.

Receptor 2 of the human epidermal growth factor (HER2/neu, c-erbB2) is a 185 kDa proto-oncogene protein characterized by an overexpression in some oncological diseases, including 30% of mammary glands cancers, as well as tumors in the ovary, stomach and other organs of the human body. Since HER2- tumor status testing is the essential part of a successful cancer treatment, the expression and purification of substantial amounts of the extracellular domain (ECD) of HER2 is an important task. The production of ECD HER2 in Escherichia coli has several advantages over the use of eukaryotic expression systems, but the bulk of the recombinant product in bacteria accumulates as insoluble protein inclusion bodies. In this study, we obtained ECD HER2 in Escherichia coli as insoluble inclusion bodies and elaborated a simple, efficient, and fast protocol for the solubilization, refolding, and isolation of the protein in soluble form.

Characteristics of bacterial biofilms during long-term culturing.

We studied properties of bacterial biofilms during long-term culturing. The biofilms were preserved for more than 90 days under the chosen conditions. At the same time, amounts of matrix and cells underwent periodic changes. The biomass of the biofilms decreased approximately every 7 days and then returned to the previous values.

Formation and structure of mixed bacterial communities.

Mixed bacterial communities are formed by unrelated bacteria on solid media. Mixed bacterial communities on solid media are similar to "classical" colonies and are formed after the growth of a large number of unrelated bacteria simultaneously plated onto a limited area of agar. The morphology of the mixed bacterial communities was similar for different combinations of bacteria and did not change when the bacteria were plated on different media. Different bacterial strains form zones of individual and mixed growth in the structure of mixed bacterial communities. The results of electron microscopic examination indicate that mixed bacterial communities are isolated from their external environment by a surface film. The basic part of this film is formed by an elementary membrane. The membrane of the surface film of mixed bacterial communities is a stable structure occupying a large surface area. The results of this investigation seem to indicate the existence of a special type of co-operation between different species of bacteria. This type of co-operation may be very important in the regulation of interactions between different bacteria and between bacteria and the environment.

Ultrastructure of colony-like communities of bacteria.

Colony-like communities are poorly studied forms of bacterial growth on agar. These communities are formed after the growth of large amounts of bacteria simultaneously plated onto a limited area of agar, while "classical" colonies are formed as a result of single bacterial cell multiplication. Colony-like communities of Gram-negative and Gram-positive bacteria differ from "classical" microbial colonies in their ultrastructural organization. Almost every cell in colony-like communities has an individual capsule-like envelope (glycocalyx). The cells in these communities are characterized by accelerated ageing. In the course of their development both bacterial colony-like communities and "classical" colonies produce a film, the basic part of which is represented by an elementary membrane. In contrast to "classical" colonies, the thickness of the amorphous layers of this film in colony-like communities did not significantly increase after 24 h of cultivation. The formation of a three-dimensional network of cells in colony-like communities is similar to this process in "classical" colonies. The intercellular matrix of colony-like communities contains numerous membrane vesicles, and has a more amorphous structure and higher electron density than that of "classical" bacterial colonies.

Effect of subinhibitory concentrations of antimicrobial agents on virulence factors of Shigella flexneri 2a and Escherichia coli O124.

The effect of subinhibitory concentrations of rifampicin, chloramphenicol, tetracycline and nalidixic acid on the interaction of Shigella flexneri 2a and Escherichia coli O124 with HeLa cells was examined. Antimicrobial agents altered adhesion, penetration and intracellular multiplication of the bacteria, as well as re-infection of adjacent cells. Chloramphenicol increased the virulence of the bacterial strains whereas nalidixic acid, tetracycline and rifampicin diminished it.

Colony-like communities of bacteria.

The morphology and some other biological properties of colony-like communities are described. Colony-like communities are formed after the growth of large numbers of bacteria simultaneously plated onto the limited area of agar. The morphology of colony-like communities of bacteria of different genera and species is similar and differs from that of colonies of these microbes. The number of colony-forming units reaches a maximal value at 24 h and does not depend on the number of bacteria in inocula.

Ultrastructure of the surface film of bacterial colonies.

The structure of the surface of colonies of various Gram-negative and Gram-positive bacteria was examined by transmission electron microscopy. The results indicate that bacterial colonies in the course of their development produce a film which becomes thicker with increased duration of growth. The basic part of the film is an elementary membrane, which is a stable structure with a large surface area. The inner and outer surfaces of the film membrane are covered by amorphous layers. These layers are thicker in the surface film of Gram-negative bacterial colonies than in those of Gram-positive bacteria. Membrane vesicles from the bacterial colonies take part in the formation of the surface film. The presence of the film on the surface of the colonies of different bacteria suggests that this structure may play an important role.

Surface films of Escherichia coli colonies.

Escherichia coli colony surfaces were examined using SEM and TEM. The results indicated that bacterial colonies in the course of their development produce surface films which become thicker with increased growth duration. Membrane vesicles contribute to the formation of the surface film. The complex organization of the film suggests that it may perform specific functions.

Morpho-physiologic characteristics of Escherichia coli and Shigella flexneri 2a carrying the htpR15 gene.

Electron microscopic examination of the morphology of normal Escherichia coli MC4100 and Shigella flexneri cells and their htpR-defective recombinants has shown the presence in the latter of noncrystalline granules after growth at 37 degrees C. The defect of the htpR gene leads to some changes in ultrastructure of bacterial colonies and the intensification of the processes of development and aging of colonies as integral structures. These phenomena are manifested by early formation of intercellular contacts and thick surface films as well as the enhanced destruction of microorganisms. The recombinant Shigella strain grown at 30 degrees C retained its ability to provoke keratoconjunctivitis.

Ultrastructural features of microbial colony organization.

The ultrastructure of microbial colonies was studied. Inside the colonies three types of intercellular contacts were demonstrated. In the colonies of Gram-negative bacteria, the cells were found to be connected by tight adhesions of outer membranes of the cell walls and membrane bridges. In the colonies of Gram-positive bacteria, the intercellular contacts were formed by fusion of peptidoglucan layers of the cell walls. Bacterial cells were differentiated by the presence of a capsule-like envelope. The obtained data indicate the existence of elements of cellular cooperation and specialization in microbial colonies.

Comparative characterization on the segmented RNA structure of influenza viruses A/Singapore 1/57 and A/Hong Kong 1/68.

A comparative characterization of the segmented RNA structure of A/Singapore 1/57 and A/Hong Kong 1/68 influenza viruses was done by polyacrylamide gel electrophoresis. The genomes of the viruses studied consist of 6 segment classes, with a total molecular weight of approximately 4 million daltons. The mathematical method suggested allows to define the number of RNA fragments, which is equal to 8-9, with a total molecular weight of about 6 million daltons. Electrophoretic patterns of the viruses investigated have individual features.