Oxidative and nitrosative stress in Staphylococcus aureus biofilm

J.E. ARCE MIRANDA, C.E. SOTOMAYOR, I. ALBESA AND M.G. PARAJE

FEMS MICROBIOLOGY LETTERS

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Federation of European Microbiological Societies (Blackwell Publishing Ltd.) The Netherlands. ; Año: 2011 vol. 315 p. 23 - 29

0378-1097

Diverse chemical and physical agents can alter cellular functions associated with oxidative metabolism, thus stimulating the production of reactive oxygen species (ROS) and reactive nitrogen intermediates (RNI) in planktonic bacterial physiology. However, more research is necessary to determine the precise role of cellular stress in biofilm. The present study was designed to address the issues of Staphylococcus aureus biofilm formation with respect to the generation of oxidative and nitrosative stress. We studied three pathogenic S. aureus clinical strains and an ATCC one exposed to a different range of culture conditions (time, temperature, pH, reduction and atmospheric conditions) by quantitative methods of biofilm detection. We observed that cellular stress could be produced inside biofilms, thereby affecting their growth, resulting in an increase of ROS and RNI production, and a decrease of the extracellular matrix under unfavorable conditions. These radical oxidizers could then accumulate in an extracellular medium and thus affect the matrix. These results contribute to a better understanding of the processes that enable adherent biofilms to grow on inert surfaces and lead to an improved knowledge of ROS and RNI regulation, which may help to clarify the relevance of biofilm formation in medical devices.