[Bacteriological monitoring of patients with periimplantitis (preliminary study)].

Studied the microflora properties of pockets around implants of 14 patients at the age of 35-68 years old. The research has shown the presence of pathogens, who p included into PRC diagnosis. Lhe research also revealed high prevalence of obligate piriodontak pathogens in areas of inflammation during periimplantitis. with both full and partial adentia.

Enzymes of SPZ7 phage: isolation and properties.

Bacteriophage enzyme preparations exolysin and endolysin were studied. Exolysin (a phage-associated enzyme) was obtained from tail fraction and endolysin from phage-free cytoplasmic fraction of disintegrated Salmonella enteritidis cells. A new method for purification of these enzymes was developed, and their molecular masses were determined. The main catalytic properties of the studied enzymes (pH optimum and specificity to bacterial substrates) were found to be similar. Both enzymes lyse Escherichia coli cells like chicken egg lysozyme, but more efficiently lyse S. enteritidis cells and cannot lyse Micrococcus luteus, a good substrate for chicken egg lysozyme. Similar properties of exolysin and endolysin suggest that these enzymes are structurally similar or even identical.

The ability of flagellum-specific Proteus vulgaris bacteriophage PV22 to interact with Campylobacter jejuni flagella in culture.

BACKGROUND: There has been a recent resurgent interest in bacteriophage biology. Research was initiated to examine Campylobacter jejuni-specific bacteriophage in the Russian Federation to develop alternative control measures for this pathogen. RESULTS: A C. jejuni flagellum-specific phage PV22 from Proteus vulgaris was identified in sewage drainage. This phage interacted with C. jejuni by attachment to flagella followed by translocation of the phage to the polar region of the bacterium up to the point of DNA injection. Electron microscopic examination revealed adsorption of PV22 on C. jejuni flagella after a five minute incubation of the phage and bacteria. A different phenomenon was observed after incubating the mix under the same conditions, but for twenty minutes or longer. Phage accumulated primarily on the surface of cells at sites where flagella originated. Interestingly, PV22 did not inject DNA into C. jejuni and PV22 did not produce lytic plaques on medium containing C. jejuni cells. The constant of velocity for PV22 adsorption on cells was 7 x 10(-9) ml/min. CONCLUSION: It was demonstrated that a bacteriophage that productively infects P. vulgaris was able to bind C. jejuni and by a spot test that the growth of C. jejuni was reduced relative to control bacteria in the region of phage application. There may be two interesting applications of this effect. First, it may be possible to test phage PV22 as an antimicrobial agent to decrease C. jejuni colonization of the chicken intestine. Second, the phage could potentially be utilized for investigating biogenesis of C. jejuni flagella.

Uncommon properties of pLD105 conjugative plasmid.

Plasmid pLD105 isolated from a clinical strain of E. coli determines nitrofuran resistance due to inactivation of low-molecular-weight nitrofuran reductase subunit. pLD105 plasmid belongs to IncF. It is a conjugative plasmid and mobilizes chromosome markers, but is not transmitted to strains containing other plasmids. However, the presence of pLD105 plasmid in the recipient strain does not prevent incorporation of other plasmids, including nonconjugative ones. Transfer of nonconjugative plasmids from the donor to a recipient strain carrying pLD105 was denoted as "reverse donation".

[Examining interaction of phages with microorganisms by fluorometry and electro-orientation spectroscopy]. / Izuchenie vzaimodeistvii fagov i mikroorganizmov s ispol'zovaniem metodov fliuorimetrii i élektroorientatsionni spektroskopii.

Bacterial sensitivity to different various phages was examined by electro-orientation spectroscopy, fluorometry, and electron microscopy. The strains of Pseudomonas aeruginosa, Staphylococcus aureus, Yersinia pestis, Mycobacterium smegmatis, and Xanthomonas campestris were used. The fluorescence intensity of a membranotropic agent in the ANS-cell-phage system was shown to depend on the interaction of a bacterial virus and a microorganism. Fluorometric data correlated with electro-orientation spectroscopic findings. An analysis of the low-frequency site makes it possible to determine phage adsorption on the bacterial surface. The changes in electro-orientation effects at high frequencies suggest that there are barrier dysfunctions in the external membranes and that there is cellular phage reproductions. Whether fluorometry and electro-orientation spectroscopy can be further used for rapid identification of microorganisms by using phages is discussed.

[Properties of MTPN11 mycobacteriophage]. / Svoistva mikobakteriofaga MTPN11.

Some characteristics of the poorly studied phage MTPH11, which is used for identification of mycobacteria, are presented. The phage has an isometric head and a long noncontractile tail (B1 morphotype). The attachment apparatus of this phage includes a basal plate composed of two joint disks and a single tail fiber. The constant of phage adsorption on Mycobacterium smegmatis ATCC607 cells is 6.6 x 10(-9) ml/min. The latent infection period in the MTPH11-host strain 607 system in 65 min; phage progeny ranges from 30 to 40 virions per one cell. The constant of phage inactivation with a homologous antiserum is 50 min-1. The buoyant density of intact MTPH11 virion in CsCl amounts to 1.520 g/cm3. The phage is susceptible to chloroform, retains lytic activity within a pH range of 5 to 9, and is resistant to inactivating agents. The G + C content of the phage DNA is 63 mol%.

[Study of the interaction of MTPN11 mycobacteriophage with host cells based on electron microscopy, fluorimetry, and electro-oriented spectroscopy]. / Izuchenie vzaimodeistviia mikobakteriofaga MTPN11 s kletkoi-khoziainom na osnove élektronnoi mikroskopii, fluorimetrii i élektro-orientatsionnoi spektroskopii.

According to electron-microscopic data, various cells in the M. smegmatis ATCC607 population interact differently with phage MTPH11. Fluorometric studies of phage-host interactions were performed using a membranotropic fluorescent probe, 8-anilino-1-naphthalene sulfonate (ANS). Changes in the electric characteristics of mycobacterial cells infected with the phage were studied by electro-orientational (EO) spectroscopy. The problem of the employment of fluorometry and EO spectroscopy for rapid phage typing of mycobacteria is discussed.

[Initial stages of interaction of temperate phage 04 with Pseudomonas aeruginosa cells]. / Izuchenie nachal'nykh stadii vzaimodeistviia umerennogo faga 04 s kletkoi Pseudomonas aeruginosa.

The first steps of the interaction of the temperate pilus-dependent phage 04 with susceptible and 04-lysogenic cells of Pseudomonas aeruginosa were investigated. The 04-lysogenic cells retained their ability to adsorb viral particles on the pili. However, after the translocation to the cell surface, the bacteriophage failed to infect the immune microorganism. It is assumed that was modified the surface of 04-immune cells due to lysogenic conversion, and this modification presented the terminal tail fibers of viral particles interacting from with the outer membrane of P. aeruginosa cells.

[Characterization of B-type bacteriophages adsorbed on Pseudomonas aeruginosa pili]. / Kharakteristika bakteriofagov B-tipa, adsorbiruiushchikhsia na piliakh Pseudomonas aeruginosa.

Pilus-dependent B-morphotype bacteriophages isolated from various sources were studied. The adsorption of phages on Pseudomonas aeruginosa pili was proven. Electron-microscopic examination of the morphology of phages was carried out, and the adsorption properties were partially described. It was suggested that adsorption apparatuses of different pilus-dependent B-phages are alike with respect to structure and function.

[Transfer of bacteriophage PRD1 genes into modified plasmid Sa of Escherichia coli and Francisella tularensis cells]. / Perenos genov bakteriofagov PRD1 v modifitsirovannye plazmidoi Sa kletki Escherichia coli i Francisella tularensis.

The donor specific bacteriophage PRDI has been shown to mediate the genes transfer into Escherichia coli and Francisella tularensis cell under certain conditions. It is necessary for the process that the recipient cells inherit the plasmids determining absorbtion of bacteriophages on the cellular surface while the transferred genes are able to be expressed. The frequencies of the tet-gene transfer from the plasmid pSKFT5 into Escherichia coli and Francisella tularensis 15 cells inheriting the plasmid Sa are, correspondingly, 10(-6) and 10(-7) clones per bacteriophage plaque.

[Comparison of the structural-functional properties of DNA-dependent RNA polymerase of the tularemia microbe and intestinal bacterial]. / Sravnenie strukturno-funktsional'nykh svoistv DNK-zaviskmykh RNA- polymeraz tuliaremiinogo mikroba i kishechnoi palochki.

The subunit compositions of RNA-polymerases from Escherichia coli and Francisella tularensis were compared. The activities of the enzymes on the corresponding chromosomal DNAs and their mixtures were defined.

Formation of complexes between long tail fibres and substructural elements of phage T4D.

Complexes of substructural elements of bacteriophage T4 (baseplates, baseplate-core complexes) with long tail fibres were obtained for the first time by complementation in vitro. A study of the organization of the complexes was carried out by PAGE, electron microscopy and sedimentation analysis. About 90% of baseplates and baseplate-core complexes were combined with fibres. However, the number of the attached fibres varied from one to six. On the basis of the data obtained, we proposed that the attachment of long tail fibres can occur before the assembly of the whole bacteriophage.

[Structural changes in proteins of the bacteriophage T4 basal plate resulting from the attachment of long fibrils]. / Strukturnye perekhody belkov bazal'noi plastinki bakteriofaga T4 pri prisoedinenii dlinnykh fibrill.

The effect of the attachment of long tail fibers on the structure of proteins of the bacteriophage T4 baseplate was studied by digital processing of electron microscopic images. The attachment of the long fibers was found to result in dramatical changes of the proteins of the baseplate plag, while the wedges, to which the long fibers are attached, undergo only slight changes. We studied the baseplates with one to six attached fibers and found that the attachment of one fiber resulted in the change of the entire baseplate, although the wedge located in the vicinity of the fiber attachment changed to a greater extent. Only after the attachment of three and more fibers the changes of the same kind occurred through the entire baseplate.

[Proteins of the basal plate of bacteriophage T4 participating in the contractile impulse]. / Belki bazal'noi plastinki bakteriofaga T4, uchastvuiushchie v peredache dvigatel'nogo impul'sa.

Reversible linking of proteins with Cu2+ and Ni2+ ions was used to study the topography of the structural proteins of bacteriophage T4 basal plate. Gene products (GP) 9 and 10 were found to directly contact the proximal part of long fibrils (GP34). GP27, GP54 and GP5 interact with the lower disk of the contractive sheath (GP18), while GP48 and GP54 are in contact with the core (GP19). The proteins of the sheath (GP18) and the core (GP19) were found to have contact over the whole tail length.