Effect of oxidative stress on cell wall morphology in four pathogenic Candida species

Candida species are a primary cause of high mortality in immunocompromised and hospitalized patients. The cell wall (CW) of these pathogens is the first structure contacted by the reactive oxygen species (ROS) generated during respiratory bursting in phagocytic cells. The purpose of this work was to evaluate the effect of oxidative stress on CW and some metabolic activities of C. albicans, C. glabrata, C. krusei and C. parapsilosis. Data revealed that C. krusei is more resistant to H2O2, while C. albicans is more resistant to O2•‾ ions. It was also observed that cells exposed to oxidative stress transited from the normal, oval morphology to other aberrant forms that exhibited indentations and protrusions. In addition, oxidative stress caused damage not only to the CW, but also altered a number of cell biological functions, such as lipidic peroxidation, antioxidant capacity, protein carbonylation and catalase activity. The morphological and other cellular changes undergone by Candida cells exposed to ROS in vitro are possibly similar to those occurring in vivo, and therefore may be important during infection and persistence of the pathogen in the human host.