Previous Article | Next Article ![]()
Infection and Immunity, December 2001, p. 7396-7401, Vol. 69, No. 12
Research Service and Department of Internal Medicine,
Veterans Affairs Medical Center
Received 29 June 2001/Returned for modification 15 August
2001/Accepted 6 September 2001
Expression of superoxide dismutases (FeSOD and MnSOD) and catalases
by laboratory strains of Pseudomonas aeruginosa is
modulated by exogenous factors. Whether clinical isolates behave
similarly and whether antioxidant enzyme expression influences
P. aeruginosa virulence remain unclear. Fifty-seven
P. aeruginosa blood culture isolates, plus seven pairs
of blood and local-site isolates, were examined for FeSOD, MnSOD, and
catalase production in vitro. Under iron-replete growth conditions
FeSOD and catalase activities were maximized. MnSOD was not detected.
FeSOD and catalase activity decreased under iron-limited growth
conditions, whereas MnSOD activity appeared. SOD and catalase activity
did not change with site of isolation or by patient. MnSOD could not be
expressed by one isolate due to a missense mutation in
sodA that produced a premature stop codon. Eleven
percent of the isolates expressed a novel, rapidly migrating MnSOD that
was associated with missense mutations in the normal stop codon of
sodA. We conclude that clinical P.
aeruginosa isolates vary little in FeSOD and catalase
expression. Some strains produce a newly described MnSOD variant,
whereas one is deficient in MnSOD production. The absence of MnSOD
expression in a P. aeruginosa strain causing invasive
human disease indicates that MnSOD is probably not essential for
P. aeruginosa virulence.
0019-9567/01/$04.00+0 DOI: 10.1128/IAI.69.12.7396-7401.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Antioxidant Enzyme Expression in Clinical Isolates
of Pseudomonas aeruginosa: Identification of an
Atypical Form of Manganese Superoxide Dismutase
Iowa City, Iowa City, Iowa
522461; Departments of Internal
Medicine2 and
Pathology5 and The Free Radical
and Radiation Research Program of the Department of Radiation
Oncology,3 University of Iowa College of
Medicine, Iowa City, Iowa 52242; and Department of
Molecular Genetics, Biochemistry, and Microbiology, University of
Cincinnati, Cincinnati, Ohio 452674
*
Corresponding author. Mailing address: University of
Iowa Hospitals and Clinics, Department of Internal Medicine, SW54, GH, Iowa City, IA 52242. Phone: (319) 734-3564. Fax: (319) 356-4600. E-mail: bradley-britigan{at}uiowa.edu.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»