Light effect and reactive oxygen species in the action of ciprofloxacin on Staphylococcus aureus

BECERRA MC; SARMIENTO M; ARGÜELLO GA; ALBESA I

Elsevier Science

Año: 2004 vol. 76 p. 13 - 13

p style="TEXT-ALIGN: justify; LINE-HEIGHT: 200%; TEXT-INDENT: 35.45pt; MARGIN: 0cm 0cm 0pt; mso-pagination: widow-orphan" class="MsoNormal">Oxygen consumption by Staphylococcus aureus ATCC 29213 sensitive to ciprofloxacin was determined with an oxygen selective electrode. Increase in the O2 consumption was observed with 0.45 µg/mL ciprofloxacin while higher concentrations gave rise to a reduction of O2 consumption. Resistant S.aureus strain did not show increase of O2 consumption in presence of ciprofloxacin. Nitro Blue Tetrazolium assay showed that production of reactive oxygen species (ROS) increased intracellularly in sensitive bacteria incubated with this antibiotic. The exposition to UV light (360 nm) augmented the intracellular oxidative stress of S.aureus and provoked increment of ROS in extracellular media. Generation of singlet oxygen O2 (1