Catalase, Superoxide Dismutase, and Staphylococcus Aureus Virulence

186 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1985.Staphylococcus aureus is known to possess a wide variety of parameters that enable it to defend itself against host defense mechanisms. One of the ways the body defends itself against microbial attack is by producing superoxide radicals and hydrogen peroxide. These oxygen-free radicals are known to kill bacterial cells. The aim of this study was to investigate the relationship between catalase and superoxide dismutase (the enzymes that degrade hydrogen peroxide and superoxide radicals, respectively) and virulence of Staphylococcus aureus.Staphylococcus aureus isolates were obtained from a group of patients hospitalized due to staphylococcal infection. A second set of isolates was obtained from healthy volunteers. Catalase and superoxide dismutase specific activity levels were found to be markedly higher in the clinical isolates. Moreover, the Staphylococcus aureus isolates obtained from the clinically ill group were found to survive longer in environments containing superoxide radicals and hydrogen peroxide.To further the study of the relationship of Staphylococcus aureus virulence to catalase and superoxide dismutase, staphylococcal cells were superoxide dismutase. Less weight gain inhibition was observed for mice injected into neonatal mice. The growth pattern of the animals was used as an index of virulence. Virulent Staphylococcus aureus was shown to cause an inhibition of the growth rate of the injected mice over a period of five days. The highest growth rate inhibition was found for mice injected with isolates having high activities of both catalase and injected with isolates having high catalase and low superoxide dismutase. Lower weight gain inhibition was seen in mice injected with isolates having low catalase and high superoxide dismutase; and, least weight gain inhibition was observed in mice injected with isolates having low catalase and low superoxide dismutase activities.This study provides evidence to support the theory that catalase and superoxide dismutase, are two factors important to the virulence of Staphylococcus aureus.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD