Description of a Novel Adhesin ofMycobacterium aviumSubsp.paratuberculosis

Abstract

The binding and ingestion of Mycobacterium avium subsp. paratuberculosis (MAP) by host cells are fibronectin (FN) dependent. In several species of mycobacteria, a specific family of proteins allows the attachment and internalization of these bacteria by epithelial cells through interaction with FN. Thus, the identification of adhesion molecules is essential to understand the pathogenesis of MAP. The aim of this study was to identify and characterize FN binding cell wall proteins of MAP. We searched for conserved adhesins within a large panel of surface immunogenic proteins of MAP and investigated a possible interaction with FN. For this purpose, a cell wall protein fraction was obtained and resolved by 2D electrophoresis. The immunoreactive spots were identified by MALDI-TOF MS and a homology search was performed. We selected elongation factor Tu (EF-Tu) as candidate for further studies. We demonstrated the FN-binding capability of EF-Tu using a ligand blot assay and also confirmed the interaction with FN in a dose-dependent manner by ELISA. The dissociation constant of EF-Tu was determined by surface plasmon resonance and displayed values within the μM range. These data support the hypothesis that this protein could be involved in the interaction of MAP with epithelial cells through FN binding.

Elongation Factor Thermo Unstable (EF-Tu) Moonlights as an Adhesin on the Surface of Mycoplasma hyopneumoniae by Binding to Fibronectin

“…EF-Tu is also identified as a major cell surface protein in Mycobacterium leprae (Marques et al, 1998 ). The ability of EF-Tu to function as a fibronectin-binding protein in several bacterial pathogens, including M. pneumoniae (Balasubramanian et al, 2008 ), Streptococcus suis (Li et al, 2015 ), and Mycobacterium avium (Viale et al, 2014 ), provided evidence of its biological versatility. A previous study and our flow cytometry analysis confirmed the membrane distribution of EF-Tu in M. hyopneumoniae (Reolon et al, 2014 ).…”

Comparative genomic analysis of Myroides odoratimimus isolates

“…It is also an adhesion/invasion factor secreted by microbes during infection by bacteria (like Helicobacter pylori) (Chiu, Wang, Tsai, Lei, & Liao, ) and fungi (Marcos et al., ) through binding ( Mycobacterium avium subsp. paratuberculosis ) with fibronectin on host cells (Viale et al., ). Superoxide dismutases (SODs) protect the bacteria from oxidative damage by converting endogenously generated superoxide radicals into hydrogen peroxide and oxygen, are indispensable for intraphagocytic viability for pathogenic bacteria (Dhar, Gupta, & Virdi, ), SodB is required for colonization of Helicobacter pylori in the stomach (Tsugawa et al., ).…”

The Diverse Functional Roles of Elongation Factor Tu (EF-Tu) in Microbial Pathogenesis

“…paratuberculosis to attach and invade two epithelial cell lines (Secott et al, 2002) but the identity of bacterial cell surface receptor(s) for Fn were not known. EF-Tu is a surface exposed cell wall protein in Mycobacterium avium subspecies paratuberculosis (MAP) (Viale et al, 2014). With the importance of Fn to MAP adhesion and invasion (Secott et al, 2002), and as EF-Tu is known to bind Fn in M. pneumoniae (Dallo et al, 2002; Balasubramanian et al, 2008) and A. baumannii (Dallo et al, 2012), it was investigated for its role as a Fn-binding protein.…”