Superoxide dismutase and oxygen toxicity defenses in the genus Neisseria

Abstract

Among aerotolerant cells, Neisseria gonorrhoeae is very unusual because despite its obligately aerobic lifestyle and frequent isolation from purulent exudates containing polymorphonuclear leukocytes vigorously evolving O2- and H2O2, it contains no superoxide dismutase (SOD). Strains (14) of N. gonorrhoeae were compared with each other and with strains of Neisseria meningitidis, Neisseria mucosa, and Neisseria subflava under identical growth conditions for their contents of the oxy-protective enzymes catalase, peroxidase, and SOD, as well as respiratory chain proteins and activity. The absence of SOD from N. gonorrhoeae strains was demonstrated under a variety of oxygen-stress conditions. The neisserial species showed very different SOD, catalase, and peroxidase profiles. These profiles correlated well with the tolerance of the species to various intra- and extracellular oxygen insults. The high tolerance of N. gonorrhoeae for extracellular O2- and H2O2 appeared to be due to very high constitutive levels of peroxidase and catalase activity combined with a cell envelope impervious to O2-. Nevertheless, N. gonorrhoeae 19424 was much more sensitive to an intracellular flux of O2- than were the other (SOD-containing) neisserial species. The responses of N. gonorrhoeae and N. meningitidis respiratory and oxy-protective enzymes to growth under high and low oxygen tensions were followed, and a novel response, the apparent repression of the respiratory chain intermediates, respiration, and SOD, peroxidase, and catalase activity, was observed. The gonococcal catalase was partially purified and characterized. The results suggest that the very active terminal oxidase, low pO2 natural habitat, O2-stable catalase, and possibly the high glutathione content of the organism explain its aerobic survival in the absence of SOD.

Periplasmic Superoxide Dismutase in Meningococcal Pathogenicity

“…The addition of 40 U of catalase/ml completely protected both phenotypes from killing (data not shown); in the case of the sodC mutant, this effect was obtained even if exogenous SOD was not added. These results are similar to those obtained with wild-type N. meningitidis by Archibald and Duong (1).…”

Neisseria gonorrhoeaesuppresses the oxidative burst of human polymorphonuclear leukocytes

“…In contrast, during active lower urogenital tract infection, the predominance of Opa + Gc (James and Swanson, 1978;Swanson et al, 1988;Jerse et al, 1994), in combination with increasing numbers of dead Gc and pro-inflammatory bacterial products, could overcome the suppression mediated by live Opa -Gc and stimulate the PMN oxidative burst. However, the intrinsically high resistance of Gc to ROS (Archibald and Duong, 1986;Hassett et al, 1990) as well as the ROS-mediated upregulation of gene products that protect Gc from PMN killing (Stohl et al, 2005) would aid Gc survival when confronted with the resulting PMN oxidative burst. Gc suppression of PMN oxidative metabolism may also help to explain the discrepancies in disease presentation between men and women.…”

How Helicobacter pylori Works: An Overview of the Metabolism of Helicobacter pylori

“…The superoxide anion is a highly reactive oxygen species that may be formed either as a byproduct of oxygen metabolism or as part of the oxidative burst of inflammatory cells, such as PMNL, that would occur during gastric inflammation. Pathogens such as Neisseria gonorrhoeae do not require the enzyme SOD because its outer membrane appears to resist damage by this reactive oxygen species [67]. However, H. pylori expresses SOD like most other aerobic and facultative anaerobic bacterial species.…”