alexa Macrophage oxygen-dependent antimicrobial activity. I. Susceptibility of Toxoplasma gondii to oxygen intermediates.
Microbiology

Microbiology

Journal of Bacteriology & Parasitology

Author(s): Murray HW, Cohn ZA

Abstract Share this page

Abstract A sensitive method for evaluating extracellular parasite viability was used to determine the in vitro susceptibility of virulent Toxoplasma gondii to selected oxygen intermediates. By acridine orange fluorescent staining criteria, toxoplasmas were resistant to up to either 10(-3) M reagent H2O2 or H2O2 generated by glucose-glucose oxidase. In keeping with a lack of sensitivity to H2O2, toxoplasmas contained endogenous catalase (5.7 x 10(-4) Baudhuin units/10(6) organisms). The addition of a peroxidase and halide, however, markedly accelerated killing and lowered the H2O2 requirement by 1,000-fold. In contrast, toxoplasmas were promptly killed after exposure to products generated by xanthine (1.5 x 10(-4) M) and xanthine oxidase (50 micrograms). The inhibition of this system's microbicidal activity by scavengers of O2- (superoxide dismutase) and H2O2 (catalase) indicated that although neither O2- nor H2O2 were toxoplasmacidal, their interaction was required for parasite killing. Quenching OH. and 1O2, presumed products of O2--H2O2 interaction, by mannitol, benzoate, diazabicyclooctane, and histidine, also inhibited toxoplasma killing by xanthine-xanthine oxidase. These findings suggested that O2- and H2O2 functioned in precursor roles and that OH. and 1O2 were toxoplasmacidal. The capacity of normal peritoneal macrophages to pinocytose an oxygen intermediate scavenger, soluble catalase, was also demonstrated. Appreciable extraphagosomal concentrations of catalase were achieved by exposing macrophages to 1 mg/ml of the enzyme for 3 h. Maintenance of high intracellular levels required constant exposure because interiorized catalase was rapidly degraded.
This article was published in J Exp Med and referenced in Journal of Bacteriology & Parasitology

Relevant Expert PPTs

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri & Aquaculture Journals

Dr. Krish

[email protected]

1-702-714-7001Extn: 9040

Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001Extn: 9040

Clinical Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Engineering Journals

James Franklin

[email protected]

1-702-714-7001Extn: 9042

Food & Nutrition Journals

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

General Science

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics & Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Materials Science Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Nursing & Health Care Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

Ann Jose

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001Extn: 9042

 
© 2008- 2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords