PubMed Health⌕ Search

Biomedical subjects

S M Navashin

Publications and source records attributed to S M Navashin.

At least 73 records · Page 4Linked to original sources
PubMed1988

[Aminoglycoside 3'-phosphotransferase gene: its cloning, characteristics and use as a molecular probe].

Aminoglycoside resistance genes were cloned from transconjugates of aminoglycoside resistant clinical strains of gramnegative bacteria. The resistance determinant cloned from the strains of E. coli transferred kanamycin, monomycin and neomycin resistance to laboratory strains. It was shown that the cloned resistance gene encoded the type I 3'-aminoglycoside phosphotransferase. The results of spot and blot hybridization of the gramnegative bacteria clinical strains with the Bam HI-Pst I fragment of the cloned resistance determinant were indicative of wide-spread distribution of the APH 3' (I) and closely related genes in clinical microbial populations.

Aminoglycosides↗
PubMed1986

[Molecular genetic analysis of the determinant of gentamicin resistance in Enterobacter cloned from a clinical strain].

Resistance of clinical strains of Enterobacteriaceae to aminoglycoside antibiotics and in particular to gentamicin was studied. The data on conjugation and plasmid DNA transformation of a clinical strain 10171 of E. cloacae, as well as the data on P1 transduction showed that its gentamicin resistance was due to plasmids. The gentamicin resistance determinant was cloned from the plasmid DNA with the use of the restriction sites of EcoR I, Hind III and Pst I into the vector plasmid pUC 19. Plasmids pAA1, pAA2, pAA3 and pAA4 carrying the gmr determinant were isolated. Their physical maps were constructed. The restriction analysis supplemented by the data on DNA-DNA hybridization was indicative of the identical 2.0 kb sequences in all the plasmids carrying the gmr determinant.

Chromosome Mapping↗
PubMed1986

[Status and prospects in the use of biocatalysis in the synthesis of beta-lactam antibiotics].

The present world status of using biocatalysts for production of beta-lactam antibiotics and their semiproducts is analyzed and the biocatalytic and chemical methods for production of antibiotics are compared. The requirements to the quality of biocatalysts used in production of drugs are formulated and the criteria of the efficiency of biocatalytic production processes are presented. Interrelation between the requirements to the biocatalyst quality and the efficiency of the biocatalytic production processes is examined. The general principles of development of efficient enzymatic processes including biocatalytic processes in production of beta-lactam antibiotics as closed-loop and practically wasteless systems are discussed. The main advantages of the developed production processes are illustrated by an example of large-scale processes use in manufacturing of the basic products for synthesis of beta-lactam compounds.

Anti-Bacterial Agents↗
PubMed1986

[Colonizing resistance of rats born of animals with experimental dysbacteriosis].

It was shown that long-term oral administration of rifampicin (40 mg/kg) to rats was accompanied by a marked decrease in the number of enterococci and staphylococci in their large intestine. A significant decrease in the number of colibacilli and anaerobic nonsporulating gramnegative bacteria was also observed. Discontinuation of the antibiotic administration resulted in rapid recovery of the intestinal flora with respect to all the indices tested. It was found for the first time that pregany of rats with experimental disbacteriosis was characterized by lowered colon resistance in spite of similarity in the intestinal flora of the experimental and control pregany. This was evident from increased periods of indicator microorganism retention in the animal intestine.

Animals↗