[Comparative study of apramycin-resistant microorganisms isolated from man and animals].

Apramycin-modifying strains isolated from pigs with coli bacteriosis, from humans and hospital environment were studied comparatively. Production of enzymes modifying the aminoglycoside was estimated with the radioactive cofactor procedure. E.

[Conjugation transfer of plasmid resistance to gentamycin and other antibiotics in clinical strains of Ps. aeruginosa].

A possibility of conjugation transfer of the markers of the plasmid resistance to gentamicin and other antibiotics from 10 clinical strains of Ps. aeruginosa, isolated from burn patients to the recipient strain of Ps. aeruginosa PTO 629 Rfr was shown.

[Action of various surface-active substances on the genetic transmission of R-plasmids in E. coli].

The effect of 4 groups of surface active-substances (SAS) on conjugation and transduction transfer of plasmid RIdrd from the donor of E. coli J 5-3 to the recipient of E. coli C600 was studied.

[Conjugational transfer of R factor RP1 in Ps. aeruginosa and the possibility of inhibiting this process with a series of substances].

It was shown that the conjugation system of Ps. aeruginosa PAO 2604 X PTO 629 rifr used for transfer of the plasmid markers of R-factor RPI was a convenient model for a number of genetic investigations (the rate of transfer of the antibiotic resistance markers was 2.2 X 10(-3) to 8.

[Suppression of the conjugational transfer of derepressed R factors by the dye, metachrome yellow].

Metachrome yellow widely used for preparation of nutrient media was tested with respect to its effect on conjugation of R-transfer. The standardized kinetic system described by the authors earlier was used. It was shown that metachrome yellow had a pronounced inhibitory effect on conjugation transfer of depressive R-factors RI drd and R 64 drd.

[Caffeine as an inhibitor of the conjugation transfer of R-factors. A study of certain aspects of the mechanism of action of caffeine on the conjugation transfer of R-factors].

Some aspects of the inhibitory effect of caffeine on conjugation transfer of R-factors described by the authors earlier were studied. The effect of the above substance on the donor and recipient competence was tested in experiments with cultivation of the parent strains for 18 hours in the presence of caffeine. For this purpose the effect of caffeine on reduction of the donor and recipient cell competence after starvation in a physiological solution was investigated.

[Caffeine as an inhibitor of the conjugation transfer of R-factors. A study of the quantitative effect of caffeine on the conjugation transfer of R-factors].

The effect of caffeine on the conjugation transfer of R-factors was studied using a standartized kinetic conjugation system described earlier. It was shown that caffeine had a pronounced inhibitory effect on R-factor transfer. The inhibition coefficients at a caffeine concentration of 2000 gamma/ml were from 2.