Development of a Bacteriophage Complex with Superhydrophilic and Superhydrophobic Nanotextured Surfaces of Metals Preventing Healthcare-Associated Infections (HAI).

We studied antibacterial properties of organo-inorganic hybrid coatings on the AMg2 aluminum alloy including superhydrophilic and superhydrophobic nanotextured metal substrates with applied bacteriophage particles. Bactericidal activity of surfaces after artificial contamination with a bacterial suspension was evaluated. To increase bactericidal effect of the plates, bacteriophage was sorbed on their surface. In the experiments simulating possible spreading of HAI pathogens, higher bactericidal activity of superhydrophilic surfaces in comparison with superhydrophobic ones. Application of bacteriophage particles did not prevent primary colonization of textured metal surfaces by strains used in the experiment, but in some cases increases their bactericidal activity.

[The development of Endo growth medium for detection and identification of enterobacteria.]

The purpose of study is to develop a traditional Endo's growth medium with the view of suppression of swarming of Proteus vulgaris and Proteus mirabilis. The object of study was a commercial dry Endo's growth medium. The inoculation of reference strains of enterobacteria and clinical sample (feces, urine, phlegm) was implemented according the normative documents. It is demonstrated that brining into Endo's growth medium tryptophan and sodium salts of bile acids in a particular ratio of their concentrations suppressed swarming of Proteus vulgaris and Proteus mirabilis. The obtained results demonstrated that application of enhanced Endo's growth medium significantly increases its differential and diagnostic characteristics.

[Vaginal microflora in girls of prepuberal age]. / Mikroflora vlagalishcha u devochek prepubertatnogo vosrasta.

The bacteriological study of vaginal microflora in 24 clinically healthy girls aged 7-8 years was carried out. Two criteria of normal vaginal biocenosis in girls of prepuberal age were proposed. The proportion of hemolytic bacteria in the vagina of a girl of prepuberal age could reach 100% of all microflora, provided the total bacterial count (TBC) exceed average values. A high proportion of hemolytic bacteria in the vaginal microflora of girls of prepuberal age in combination with a high level of TBC (even with TBC not exceeding the upper limit of its normal value) could probably by regarded as a border state. No fungi of the genus Candida should be isolated from vagina in girls of prepuberal age. Facultative anaerobic microflora was represented mainly by Staphylococcus epidermidis and S. saprophyticus. In 64.3 +/- 12.8% of cases bifidobacteria were detected in the girls vagina.

[Cytopathogenic action of intact and antibiotic-altered populations of Bordetella pertussis on a human amnion cell culture]. / Tsitopatogennoe deistvie intaktnykh i izmenennykh antibiotikami populiatsii Bordetella pertussis na kul'turu kletok amniona cheloveka.

Cytopathogenic and adhesive action of intact B. pertussis population and population changed under the effect of antibiotics was studied comparatively. It was shown that the level and character of the changes in the cell culture of line FL human amnion depended on the antibiotic used in the experiments. Populations of B. pertussis changed under the effect of tetracycline had the highest cytopathogenic and adhesive activity, while the activity of the population changed under the effect of erythromycin was the least. The decrease in the cytopathogenic and adhesive activity of B. pertussis changed under the effect of erythromycin correlated with lowering of the toxicity and the loss of the main agglutinogenic factors of the surface of the bacteria cell wall. The increase in the toxicity of the population changed under the effect of tetracycline was accompanied by changes in the cytopathogenic and adhesive properties of the culture.

[Electron microscopic study of the interaction of cultures of Bordetella pertussis altered by antibiotic action with a human amniotic cell culture]. / Elektronno-mikroskopicheskoe izuchenie vzaimodeistviia kul'tur Bordetella pertussis, izmenennykh pod deistviem antibiotikov, s kul'turoi kletok amniona cheloveka.

The adhesive properties of B. pertussis subjected to long-term subcultivation on nutrient media with antibiotics were studied with electron microscopy and it was shown that under the action of erythromycin the adhesive capacity of B. pertussis markedly decreased. Subcultivation on media with tetracycline did not lower the adhesive activity of B. pertussis. Changes in the adhesive properties of B. pertussis under the action of the antibiotics correlated with changes in toxicity, serovars and ultrastructure of the bacteria in the population.

[Glutamine synthetase content and immunochemical analysis of different strains of Bordetella pertussis]. / Soderzhanie glutaminsintetazy i immunokhimicheskii analiz razlichnykh shtammov Bordetella pertussis.

In this investigation 3 groups of strains isolated from pertussis patients have been studied: typical (group 1), atypical in their cultural properties (group 2), unidentified Gram-negative bacilli agglutinated by pertussis and parapertussis antitoxins (group 3). Besides, B. pertussis cultures, obtained by subculturing 2 museum strains and 2 newly isolated strains on synthetic casein-charcoal agar with subinhibiting doses of antibiotics or specific immune sera added, have been studied. As indicated by the results of this study, strains belonging to groups 1 and 2 contain glutamine synthetase, while in strains of group 3 this enzyme is absent. In immunoelectrophoresis strains of group 3 have been found to contain not a single antigen similar to the antigens of strains belonging to groups 1 and 2. Electrophoresis in polyacrylamide gel has revealed to differences in the protein spectrum of the strains of these 3 groups. The investigation has shown that the determination of glutamine synthetase and immunoelectrophoresis can be used for the differentiation of B. pertussis from similar Gram-negative bacilli. B. pertussis strains, changed as the result of experiments with antibiotics and specific immune sera, have also been shown to retain their antigenic composition and protein spectrum and to have no essential difference in the content of glutamine synthetase.

[Cryofractographic study of intercellular junctions in the populations of agar-cultivated Bordetella pertussis]. / Kriofraktorgraficheskoe izuchenie mezhkletochnykh sviazei v populiatsiiakh agarovykh kul'tur Bordetella pertussis.

The characteristic feature of replicas obtained from the freeze-fractures of B. pertussis unfixed cultures developing on casein charcoal agar for 1-7 days is the associative growth of highly polymorphic cells, ensured by the ramified system of intercellular connections (IC) formed by the derivatives of the outer layers of the cell wall. This proves that the associative location of bacterial cells, linked by numerous IC, in the preparation is not the artefact appearing in the process of their chemical fixation. In replicas obtained from the freeze-fractures of B. pertussis cultures, previously fixed with glutaraldehyde, osmic acid and uranyl acetate, oval cells with the cytoplasm having a relatively homogeneous structure and with the smoothed-out three-layer cell wall prevail. As a rule, IC are limited to the sites of direct contacts between individual cells.

[Ultrastructure of freshly isolated strains of Bordetella pertussis]. / Ul'trastruktura svezhevydelennykh shtammov Bordetella pertussis.

The study of the electronograms of B. pertussis strains isolated in the foci of pertussis revealed the existence of the morphological variants of these cells, differing in the character of the cell wall, the state of the cytoplasm, the presence of amorphous inclusions of medium electron-optical density. The morphological variants did not correlate with the character of B. pertussis colonies isolated from blood-charcoal agar. The ultrastructure of the cells belonging to the second morphological variant was similar to that of the cells from the museum strain, altered by tetracycline treatment in the course of the experiment.

[Morphological heterogeneity of Bordetella pertussis populations and clones (based on electron microscopy data)]. / Morfologicheskaia neodnorodnost' populiatsii i klonov Bordetella pertussis (po dannym élektronnoi mikroskopii).

Populations belonging to different serovars of B. pertussis museum strains and antibiotic-resistant clones obtained from them have been studied by electron microscopy. As a result, morphological heterogeneity and differences in the ultrastructure of the cells with respect to the cell-wall structure, the character of the cytoplasm, the size of the cells, cytoplasmic inclusions and intracellular links have been demonstrated and, proceeding from these data, two main morphological variants of the cells have been defined. The cells of the morphological variant characterized by the pliciform surface of the outer membrane and the pronounced periplasmic space prevail among the populations of the museum strains. The possibility of the isolation of antibiotic-resistant clones, differing in their morphological structure and functional properties from the initial population, has been shown. The morphological diversity of B. pertussis population is the necessary condition for the existence and development of microbial populations.

[Importance of immunoelectrophoresis in agar and disc electrophoresis in polyacrylamide gel for characterizing different strains of Bordetella pertussis]. / Znachenie metoda immunoélektroforeza v agare i diskovogo élektroforeza v poliakrilamidnom gele dlia kharakteristiki razlichnykh shtammov Bordetella pertussis.

The antigenic composition of typical and atypical B. pertussis strains obtained in the foci of pertussis infection, as well as experimentally obtained antibiotic-resistant B. pertussis strains, has been studied by the methods of immunoelectrophoresis in agar and electrophoresis in polyacrylamide gel (PAAG). Immunoelectrophoresis in agar has been found capable of differentiating B. pertussis culture from a group of unidentified morphologically similar Gram-negative bacilli by their antigenic composition and thus suitable for use as an additional criterion in the identification of atypical B. pertussis strains. PAAG electrophoresis has permitted finding differences in the set of protein antigens in the control strain and in its clones obtained by multiple subculturing in media with antibiotics added.

[Effect of penicillin and the habitat medium in the body of bacterial carriers on the intercellular bonds in populations of the meningococcus and pertussis microbe]. / Vliianie penitsillina i sredy obitaniia v organizme bakterionositelei na mezhkletochnye sviazi populiatsii meningokokka i kokliushnogo mikroba.

The relationship of the bacterial cells in populations and their adhesion activity is at present one of the research priorities in microbiological studies. The stimulating effect of penicillin on the development of morphologically different intercellular bonds (IB) in populations of the pertussis causative agent and first of all derivatives or evaginates of the cell wall membranes was observed. Morphologically similar systems and polytubular IB were detected in populations of meningococcal strains isolated from carriers having no signs of the disease. Correlation between the after-effect of penicillin and the presence of the causative agent in bacterial carriers was shown. Unknown systems of interlacing tubular structures not directly bound with the cells, the walls of which were single contour membranes were determined in the meningococcal populations treated with penicillin. IB were observed in the population in the form of transpopulation cords. Morphologically different IB playing the role of specialized organelles might be considered as factors of the functional unity of the bacterial population as a multicellular system.

[Changes in the biological properties of the pertussis microbe exposed to antibiotics]. / Izmenenie biologicheskikh svoistv kokliushnogo mikroba pri deistvii antibiotikov.

Experimental modeling of the process of variation of the pertussis causative agent grown on the casein-carbon agar medium with subtoxic doses of the widely used antibiotics was performed. Significant changes in the morphological, cultural and serological properties of the pertussis microbe, in its sensitivity to the antibiotics and bacteriocins, in the activity of glutamine synthetase and in the electrophoretic mobility of the protein components were shown. The antigen structure determined with the method of immune electrophoresis in the agar gel and the biochemical properties were the stable characteristics defining the population taxonomic position as Bordetella pertussis. Possible occurrence of atypical strains of the pertussis causative agent in the patients with the cough syndrome treated with the antibiotics is indicated. It is suggested that antibiotics may play a significant role in redistribution of subpopulations with different functional properties in the population of the pertussis microbe.

[Ultrastructural changes in populations of the pertussis microbe exposed to antibiotics]. / Ul'trastrukturnye izmeneniia populiatsii kokliushnogo mikroba pri deistvii antibiotikov.

The ultrastructural changes in the populations of the pertussis causative agent maintained for a prolonged period of time on nutrient media containing antibiotics were studied with the method of electron microscopy. Significant changes in the ultrastructure of the cells and the population composition due to the effect of tetracycline, levomycetin or erythromycin were observed. The ultrastructure of the populations affected by penicillin or streptomycin and their biological properties were most similar to those of the initial strains. The electronogrammes revealed morphological heterogeneity of the initial and experimental cultures and changes in the subpopulation composition induced by the antibiotics.