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Galina Yu. Lomakina, Natalya N. Ugarova
Kinetics of interaction of colistin with live cells Escherichia Coli studied by bioluminescent method
Abstract
Abstract. The kinetics dependences of the ATP concentration inside (ATPin) and outside (ATPex) of E. coli
cells on the colistin concentration and duration of
incubation in the LB medium and in saline were obtained
using our optimized bioluminescent method. With increasing colistin concentration and
duration of cell incubation in the nutrient medium, ATPin rapidly decreased to zero. At the
same time, ATPex
increased, reached the limit (20–30% of the initial value of ATPin ) and did not changed even after
complete cell death. The loss of a significant part of ATPin seems to be due to a decrease in
the activity of respiratory chain enzymes and ATP synthase functioning in the
inner cell membrane, damage of which during incubation with colistin leads to a
decrease in the rate and even a stop in ATP synthesis. Comparison of ATPin
and ATPex during incubation of cells in the nutrient medium
and in saline in the presence of colistin showed that colistin has a stronger
bactericidal effect on growing, metabolically active cells, while non-growing
cells deprived of nutrition are more resistant to the action of the antibiotic.
Key words: bioluminescence, firefly luciferase,
colistin, cells Escherichia coli,
ATP, viability
Copyright (C) Chemistry Dept., Moscow State University, 2002
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