Lipids and DNA Oxidation in Staphylococcus aureus as a consequence of oxidative stress generated by ciprofloxacin

BECERRA, M. C.; PÁEZ PL; LARÓVERE, L. E.; ALBESA, I

MOLECULAR AND CELLULAR BIOCHEMISTRY

Kluwer Academic

Año: 2006 vol. 285 p. 29 - 34

0300-8177

Ciprofloxacin induced an increment of reactive oxygen species in sensitive strains of Staphylococcus aureus leading to oxidative stress detected by chemiluminescence  while resistant strains did not suffer such stress. Oxidation of lipids was performed by employing thiobarbituric acid reaction to detect the formation of an amplified intermediate between reactive species oxygen  and cytoplasmic macromolecules, namely malondialdehyde (MDA). The sensitive strain presented higher peroxidation of lipids than the resistant strain. The oxidative consequence for DNA was investigated by means of bacteria incubation with ciprofloxacin and posterior extraction of DNA, which was studied by high performance liquid chromatography (HPLC). Sensitive S.aureus ATCC 29213 showed an increase of 8-oxo-7,8-dihydro-2´-deoxyguanosine (8-oxodG) respect controls without antibiotic. There was evident augment of the ratio between 8-oxodG and deoxyguanosine (dG) as a consequence of oxidation of dG to 8-oxodG considered the major DNA marker of oxidative stress. The resistant strain showed low oxidation of DNA and the analysis of ratio 8-oxodG/dG indicated lesser formation of 8-oxodG than S.aureus ATCC 29213.