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Biomedical subjects

V I Panasenko

Publications and source records attributed to V I Panasenko.

At least 19 recordsLinked to original sources

[Complementation analysis of mutants of the associative bacteria Azospirillum brasilense Sp245 and S27, defective in mobility and flagellation].

Three mutants of Azospirillum brasilense Sp245 incapable of both formation of the polar flagellum (Fla-phenotype) and swarming in semisolid media (Swa-phenotype) were characterized. These mutants were shown to have lost the 85-MDa plasmid and to carry the Tn5-Mob transposon and pSUP5011 vector in different regions of their genomes. With the use of A. brasilense Sp245 gene bank, the capacity for both polar flagellum formation and swarming was restored in the above mutants and in the previously generated transposon mutants A. brasilense Sp245 and S27. The transconjugants obtained were only slightly motile in the liquid culture. In the gene bank of Sp245, the recombinant plasmids carrying wild-type fla/swa loci were identified.

Azospirillum brasilense↗

Novel classes of Azospirillum brasilense mutants with defects in the assembly and functioning of polar and lateral flagella.

Azospirillum brasilense Sp245 has a mixed type of flagellation: a single polar flagellum (Fla) is synthesized constitutively, and abundant lateral flagella (Laf) are produced only in solid and semisolid media. In the present study, Omegon-Km Fla-Laf-, Fla-Laf+, Fla-/Mot-Laf-. Fla-/Mot-Laf+, Mot-Laf-, and Che- mutants of Sp245 were constructed in vivo. In some of the mutants, a number of cells possessed from 1 to 5 subpolar long flagella (Sfl). These Sfl provided the host cells with unusual motility patterns. Mutants producing shortened Fla and Laf were also detected. In the mutants still producing Laf, their expression retained the wild-type inducibility. However, all the mutants described were unable to form swarm rings in semisolid media. The results suggest the existence of common control or structural elements in assembly and rotation apparatus of both Fla and Laf systems. Single Omegon-Km insertions were localized in 85 MD (in two mutants) and in 120 MD (in one mutant) indigenous plasmids, as well as to least in two different regions of chromosomal DNA (in other mutants).

Azospirillum brasilense↗

Involvement of Azospirillum brasilense plasmid DNA in the production of indole acetic acid.

Indole acetic acid (IAA) production in Azospirillum brasilense strain Sp245 is controlled by a 85 MDa plasmid naturally present in this bacterium. In the presence of L-tryptophan, anthranilic acid production and almost no IAA production occurs in a derivative strain harbouring a Tn5-Mob insertion in the 85 MDa plasmid. Agrobacterium tumefaciens strain GM19023, upon transfer of Tn5-Mob labelled 85 MDa plasmid of A. brasilense Sp245, gains the ability to produce anthranilic acid.

Azospirillum brasilense↗

[Transposon mutagenesis, elimination and mobilization of plasmids in nitrogen-fixating bacterium Azospirillum brasilense Sp245].

The expressed difference in the plasmid profile of A. brasilense Sp245 is registered as a result of Tn5-Mob-mutability. Integration of the vector pSUP5011 into one of the A. brasilense Sp245 plasmid and using of the Tn5-Mob transposon to mobilize the 85Md cryptic plasmid are reported. The properties of A. brasilense Sp245 with the mutant plasmids composition (surface structure, acetylene and nitrate reduction, ability to a number of carbohydrates utilization, formation of melanin, antibiotics resistance specter) have been analyzed. The transposon Tn5-Mob insertion into the 85Md plasmid resulted in isolation of a mutant excreting a melanin-like pigment into the medium. The results suppose 85Md plasmid participation in melaninogenesis.

Azospirillum brasilense↗

[Surgical treatment of tumors of the carotid body].

In the period between 1967 and 1985 the authors operated on 5 patients with chemodectoma; their ages ranged from 29 to 39. The duration of the disease ranged from 2 to 4 years. The tumor was on the right side in 3 and on the left side in 2 patients. Carotid angiography, which was conducted in all cases, revealed a richly vascularized tumor in the region of the carotid artery bifurcation with characteristic "angulation" and "cuff" signs. Damage to the carotid arteries was avoided during the operation in 3 patients and the chemodectoma was removed subadventitionally. In 2 patients the arteries were injured. There were neither neurological complications nor fatal outcomes.

Adult↗

[Formation of pAS8-1213 cointegrate with one of the plasmids of Azospirillum brasilense Sp245].

Inheritance of the plasmid vector pAS8-1213 in Azospirillum brasilense Sp245 cells has been studied. The plasmid pAS8-1213 is shown to be uncapable of autonomous replication in the new host but able to integrate into the genetic structures of Azospirillum with high frequency. 90-95% of KmR-transconjugants of A. brasilense harbor pAS8-1213 cointegrated with the smaller host plasmid pAbSP245c(85Md). The formed cointegrate can be transferred into Azospirillum spp. 75 and RecA- strains of E. coli (HB101 and DH1) and stably maintained in these cells. The IS21 element inherent of the plasmid pAS8-1213 is supposed to participate in pAS8-1213::pAbSP245c cointegrate formation.

Azospirillum brasilense↗

[Genetic nature of the antibiotic-resistance of Lactobacillus].

One hundred and forty one strains of Lactobacillus were isolated from intestinal contents of persons being in long-term contact with antibiotics. Their sensitivity to 10 chemotherapeutic agents was studied with the method of serial dilutions in solid media under aerobic and anaerobic conditions. A single administration of antibiotics in the therapeutic doses led to selection of Lactobacillus polyresistant strains in the intestine of rats. The antibiotic resistance spectrum of the Lactobacillus cultures was unstable and changed under nonselective conditions of their storage and after their lyophilization or short-term exposure to heat. The changes in the resistance spectrum were accompanied by changes in the plasmid profile. An electrophoretogram of plasmid DNA from the intestinal isolate L plantarum MT205 is presented. Relation between the marker of lincomycin resistance and the presence of plasmid DNA weighing 130 kb was shown in the isolate.

Animals↗

[Characteristics of dissociation in cultures of Aspergillus brasilense Sp7].

Peculiarities of dissociation in the cultures of nitrogen-fixating soil microorganism Azospirillum brasilense have been studied. The possible transfer among colony-morphology variants is established. The relations between variants are described by the following scheme: R in equilibrium with SR----S Electrophoretic analysis of plasmid contents in different variants of Azospirillum brasilense supposes the possible participation of plasmid DNA in the dissociation process in this microorganism.

Gram-Negative Aerobic Bacteria↗