Action of ciprofloxacin on planktonic bacteria and biofilm of Proteus mirabilis

V. AIASSA, A. I. BARNES AND I. ALBESA

Biofilms

Cambridge University Press

Año: 2007 vol. 3 p. 1 - 1

1479-0505

Proteus mirabilis can persist in biofilms, with the bacteria in this state tendingto resist antibiotic therapy. Until now, the relationship between the actionof ciprofloxacin and the production of reactive oxygen species (ROS) hasnot been studied in planktonic and biofilmic P. mirabilis. Our results showthat ciprofloxacin stimulates the production of ROS in planktonic P. mirabilis,but that the increase in ROS was observed in sensitive strains (n=4) onlyin the absence of the extrcellular matrix (ECM). This augmentation of ROSwas principally intracellular, invoking an increase in intracellular superoxidedismutase (SOD). ROS were assayed by chemiluminescence (CL) andSOD by inhibition of reduction of nitroblue tetrazolium in the presence ofmethionine, riboflavin and light. The antibiotic-resistant strains (n=4) didnot suffer oxidative stress and exhibited a higher antioxidant capacity thanantibiotic-sensitive o