[Impact of exogenous glycine on actinomycin D resistance of Staphylococcus aureus strain adapted to the antibiotic].
The impact of glycine, added to the cultivation medium, on resistance of Staphylococcus aureus strains to actinomycin D and gramicidin S was studied. The antibiotic resistant strains were isolated after cultivation of the susceptible S. aureus strain 209P on media with increasing concentrations of actinomycin or gramicidin. When the strains were grown on the glycine-containing medium. i. e. under the conditions providing replacement of D-alanine by glycine in the C-end dipeptides of peptidoglycanes, the resistance of the staphylococci to actinomycin markedly decreased. However, in the resistant cells, characterized by significant thickening of the cell walls, the peptidoglycane quantity per a biomass unit did not lower, that was evident of preservation of the wall thickness. At the same time, with addition of glycine to the medium there was observed increased ability of the cells to bind actinomycin. When the gramicidin-adapted strains were grown on the glycine-containing medium, their resistance to the antibiotic did not change. The modification of the peptidoglycane C-end dipeptides probably lowered the protective role of the thicker walls of the cells on their contact with actinomycin but not gramicidin.
V G
VG
Bulgakova
T I
TI
Orlova
V A
VA
Grushina
A N
AN
Polin
D000900:Anti-Bacterial Agents; D003609:Dactinomycin; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D005998:Glycine / Q000494:pharmacology*; D018684:Glycine Agents / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000254:growth & development*
D000900:Anti-Bacterial Agents; D018684:Glycine Agents; D003609:Dactinomycin; D005998:Glycine