Anaerobic environment of the intestine primes pathogenic Shigella for infection

Abstract

Evaluation of: Marteyn B, West NP, Browning DF et al. Modulation of Shigella virulence in response to available oxygen in vivo. Nature 465, 355–358 (2010).

Marteyn et al. have investigated the role of oxygen and the regulator FNR in infection by the intracellular enteric pathogen Shigella flexneri. FNR is active under anaerobic conditions like those present in the lumen of the distal intestine. FNR causes elongation of a secretion apparatus required for bacterial entry into cells and represses secretion of proteins that trigger entry. Higher oxygen levels present at the intestinal cell surface are sufficient to inactivate FNR, thereby derepressing secretion. Thus, bacteria are ‘primed’ in the anaerobic environment of the lumen, and entry is triggered by the aerobic conditions at the intestinal cell surface. FNR is conserved among many enteric pathogens, suggesting that regulation of virulence in response to oxygen may be widely conserved.

Keywords::

• diarrhea
• enteric infection
• FNR
• intestine
• oxygen
• Shigella flexneri
• TTSS
• type three secretion system

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.