Microbe magazine higlights paper by ITQB researchers
A bacterial perspective on the battle with the immune system
A paper by researchers from the Lab of Molecular Genetics of Microbial Resistance and collaborators has been selected to appear in the Journal Highlights section of the July issue of Microbe. Journal Highlights consists of short, 150 word summaries of the month's best American Society of Microbiology journal papers.
The paper, published in the Journal of Bacteriology, describes how the bacteria E.coli adapt to the presence of nitric oxide and hydrogen peroxide produced by the mammalian immune system upon infection.
« E. coli and Macrophages: An Intricate Choreography
In their quest to control infection, mammalian phagocytes produce nitric oxide and hydrogen peroxide. The microbes, in turn, use an array of enzymes to detoxify these and other reactive oxygen species, such as flavorubredoxin, a nitric oxide reductase. Now Ligia M. Saraiva of the Universidade Nova de Lisboa, Oeiras, Portugal, et al. show in fascinating detail that unlike under nitrosative stress by itself, exposure to both nitrosative and oxidative stresses prevents E.coli from expressing flavorubredoxin by blocking the transcription mechanism for this gene. This team shows further the unfolding choreography of the battle between bacterium and host immune system, with one and then the other gaining the advantage. “We propose that the time-dependent activation of flavorubredoxin contributes to the adaptation of E. coli to the different fluxes of hydrogen peroxide and nitric oxide to which the bacterium is subjected during the course of macrophage infection,” the investigators write. “The research may ultimately lead to development of novel therapeutic drugs that successfully eradicate antibiotic-resistant pathogens,” says Saraiva. »
Oxidative stress modulates the nitric oxide defense promoted by Escherichia coli flavorubredoxin.
J. M. Baptista, M. C. Justino, A. M. P. Melo, M. Teixeira, and L. M. Saraiva.