The Mechanism of Oxygen and Nitric Oxide Toxicity in Escherichia Coli

The presence of nitric oxide (NO) greatly accelerates the rate at which hydrogen peroxide (H2O2) kills E. coli. The goal of this study was to determine the mechanism of this synergism. The filamentation of the dead cells, and their protection by cell-permeable iron chelators, indicated that NO/H2O2 killed cells by damaging their DNA through the Fenton reaction. NO also blocked respiration, an event which previous studies have shown can stimulate oxidative DNA damage. The resultant accumulation of NADH accelerates the reduction of free flavins by flavin reductase, and these reduced flavins drive Fenton chemistry by tranferring electrons to free iron. The possibility that H2O2 and NO synergize when macrophages attack captive bacteria is discussed.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Microbiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Woodmansee, Anh Nguyen

Contributors dc:contributor

• Imlay, James A.

• Biology, Microbiology

Language dc:language

eng

Identifier

(MiAaPQ)AAI3070482

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/86646