The Acinetobacter trimeric autotransporter adhesin Ata controls key virulence traits of Acinetobacter baumannii

  • Acinetobacter baumannii is a Gram-negative pathogen that causes a multitude of nosocomial infections. The Acinetobacter trimeric autotransporter adhesin (Ata) belongs to the superfamily of trimeric autotransporter adhesins which are important virulence factors in many Gram-negative species. Phylogenetic profiling revealed that ata is present in 78% of all sequenced A. baumannii isolates but only in 2% of the closely related species A. calcoaceticus and A. pittii. Employing a markerless ata deletion mutant of A. baumannii ATCC 19606 we show that adhesion to and invasion into human endothelial and epithelial cells depend on Ata. Infection of primary human umbilical cord vein endothelial cells (HUVECs) with A. baumannii led to the secretion of interleukin (IL)-6 and IL-8 in a time- and Ata-dependent manner. Furthermore, infection of HUVECs by WT A. baumannii was associated with higher rates of apoptosis via activation of caspases-3 and caspase-7, but not necrosis, in comparison to ∆ata. Ata deletion mutants were furthermore attenuated in their ability to kill larvae of Galleria mellonella and to survive in larvae when injected at sublethal doses. This indicates that Ata is an important multifunctional virulence factor in A. baumannii that mediates adhesion and invasion, induces apoptosis and contributes to pathogenicity in vivo.

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Author:Marko Weidensdorfer, Masahito Ishikawa, Katsutoshi Hori, Dirk Linke, Bardya Djahanschiri, Ruben Iruegas, Ingo EbersbergerORCiDGND, Sara Riedel-Christ, Giulia Enders, Laura Leukert, Peter KraiczyGND, Florian RothweilerGND, Jindrich CinatlORCiD, Jürgen Berger, Katharina Hipp, Volkhard A. J. KempfORCiDGND, Stephan GöttigORCiDGND
Parent Title (English):Virulence
Publisher:Landes Bioscience
Place of publication:Austin, Tex.
Document Type:Article
Year of Completion:2019
Date of first Publication:2019/01/14
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2019/03/07
Tag:Adhesion; Galleria mellonella; HUVEC; endothelial cells; host cell response
Page Number:15
First Page:68
Last Page:81
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Institutes:Biowissenschaften / Biowissenschaften
Medizin / Medizin
Angeschlossene und kooperierende Institutionen / Senckenbergische Naturforschende Gesellschaft
Fachübergreifende Einrichtungen / Biodiversität und Klima Forschungszentrum (BiK-F)
Dewey Decimal Classification:6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit
Licence (German):License LogoCreative Commons - Namensnennung 4.0