AUTHOR=Lekmeechai Sujinna , Su Yu-Ching , Brant Marta , Alvarado-Kristensson Maria , Vallström Anna , Obi Ikenna , Arnqvist Anna , Riesbeck Kristian 

TITLE=Helicobacter pylori Outer Membrane Vesicles Protect the Pathogen From Reactive Oxygen Species of the Respiratory Burst

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01837

DOI=10.3389/fmicb.2018.01837

ISSN=1664-302X

ABSTRACT=<p>Outer membrane vesicles (OMVs) play an important role in the persistence of <italic>Helicobacter pylori</italic> infection. <italic>Helicobacter</italic> OMVs carry a plethora of virulence factors, including catalase (KatA), an antioxidant enzyme that counteracts the host respiratory burst. We found KatA to be enriched and surface-associated in OMVs compared to bacterial cells. This conferred OMV-dependent KatA activity resulting in neutralization of H<sub>2</sub>O<sub>2</sub> and NaClO, and rescue of surrounding bacteria from oxidative damage. The antioxidant activity of OMVs was abolished by deletion of KatA. In conclusion, enrichment of antioxidative KatA in OMVs is highly important for efficient immune evasion.</p>