Anaerobes may develop soft tissue infection sites after a brief passage through air, or through a more oxidizing environment than they encounter in their normal habitat. Although little information concerning the sundry effects of oxygen, antioxidant enzymes such as superoxide dismutase and catalase, and nutrient sources upon the ability of aerobes or aerotolerant species to generate a soft tissue infection, that information is virtually nonexistant for anaerobes. The purpose of the proposed research is to determine the effects of intracellular and intercellular levels of superoxide dismutase and catalase upon the ability of Bacteroides fragilis and other anaerobes to resist oxygen dependent phagocytic cell destruction, develop an experimental infection site, and withstand hyperbaric oxygen and oxygen metabolite stress. B. fragilis contains an O2-inducible superoxide dismutase. Increased levels of that enzyme impart resistance to hyperbaric oxygen stress. The susceptibility of induced and uninduced cells to phagocytic kill and their ability to generate an abscess in situ will be correlated. Catalase levels may be manipulated by varying both glucose and hemin levels during culture of B. fragilis. Cells with altered catalase levels will also be subjected to the test systems described herein. These studies are designed to seek quantitative answers to questions concerning aerotolerance and the infection process.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
2R01AI015250-07A3
Application #
3126099
Study Section
Bacteriology and Mycology Subcommittee 1 (BM)
Project Start
1978-08-01
Project End
1990-06-30
Budget Start
1987-07-01
Budget End
1988-06-30
Support Year
7
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Virginia Polytechnic Institute and State University
Department
Type
Earth Sciences/Resources
DUNS #
003137015
City
Blacksburg
State
VA
Country
United States
Zip Code
24060
Juan, J Y; Keeney, S N; Gregory, E M (1991) Reconstitution of the Deinococcus radiodurans aposuperoxide dismutase. Arch Biochem Biophys 286:257-63
Chen, Y; Gregory, E M (1991) In vivo metal substitution in Bacteroides fragilis superoxide dismutase. Free Radic Res Commun 12-13 Pt 1:313-8
Barkley, K B; Gregory, E M (1990) Tetrameric manganese superoxide dismutases from anaerobic Actinomyces. Arch Biochem Biophys 280:192-200
Pennington, C D; Gregory, E M (1986) Isolation and reconstitution of iron- and manganese-containing superoxide dismutases from Bacteroides thetaiotaomicron. J Bacteriol 166:528-32
Gregory, E M (1985) Characterization of the O2-induced manganese-containing superoxide dismutase from Bacteroides fragilis. Arch Biochem Biophys 238:83-9