Enhanced Adhesion of Campylobacter jejuni to Abiotic Surfaces Is Mediated by Membrane Proteins in Oxygen-Enriched Conditions

Abstract

Campylobacter jejuni is responsible for the major foodborne bacterial enteritis in humans. In contradiction with its fastidious growth requirements, this microaerobic pathogen can survive in aerobic food environments, suggesting that it must employ a variety of protection mechanisms to resist oxidative stress. For the first time, C. jejuni 81–176 inner and outer membrane subproteomes were analyzed separately using two-dimensional protein electrophoresis (2-DE) of oxygen-acclimated cells and microaerobically grown cells. LC-MS/MS analyses successfully identified 42 and 25 spots which exhibited a significantly altered abundance in the IMP-enriched fraction and in the OMP-enriched fraction, respectively, in response to oxidative conditions. These spots corresponded to 38 membrane proteins that could be grouped into different functional classes: (i) transporters, (ii) chaperones, (iii) fatty acid metabolism, (iv) adhesion/virulence and (v) other metabolisms. Some of these proteins were up-regulated at the transcriptional level in oxygen-acclimated cells as confirmed by qRT-PCR. Downstream analyses revealed that adhesion of C. jejuni to inert surfaces and swarming motility were enhanced in oxygen-acclimated cells or paraquat-stressed cells, which could be explained by the higher abundance of membrane proteins involved in adhesion and biofilm formation. The virulence factor CadF, over-expressed in the outer membrane of oxygen-acclimated cells, contributes to the complex process of C. jejuni adhesion to inert surfaces as revealed by a reduction in the capability of C. jejuni 81–176 ΔCadF cells compared to the isogenic strain.Taken together, these data demonstrate that oxygen-enriched conditions promote the over-expression of membrane proteins involved in both the biofilm initiation and virulence of C. jejuni.

Effects of iron limitation on growth and carbon metabolism in oceanic and coastal heterotrophic bacteria

“…Database analysis-The protein spots that had a significantly different expression following 2D gel analysis were manually excised and subjected to in-gel digestion with MultiPROBE II (Perkin Elmer) using trypsin, as previously described in Sulaeman et al (2012), to be then analyzed in liquid chromatography coupled with tandem mass spectrometry (MS 2 ), and OrbiTrap. The peak lists from the MS 2 spectra obtained were compared to the National Center for Biotechnology Information database in 2010 and 2011 (restricted to bacteria) using the Mascot Daemon search program (http://matrixscience.com).…”

Transcriptome and proteome dynamics in chemostat culture reveal how Campylobacter jejuni modulates metabolism, stress responses and virulence factors upon changes in oxygen availability

“…The way in which oxygen regulates gene expression and protein synthesis at a global level in C. jejuni is poorly understood. Previous studies have used either liquid batch or plate cultures exposed to atmospheres with various oxygen contents (Gaynor et al, 2004;Sulaeman et al, 2012;van der Stel et al, 2017), sometimes generated within gas jars. Two major drawbacks can be identified with this approach.…”

Influence of measurement and control of microaerobic gaseous atmospheres in methods for Campylobacter growth studies

“…This response was suggested by Gaynor et al (2004), in a study dedicated to the comparison of two strains of C. jejuni cultivated under microaerobic and severely O 2 -limited conditions, using a transcriptional approach. The membrane protein expression is also altered in higher oxygen concentrations (Sulaeman et al 2012). Taken together, these results indicate that C. jejuni is able to modify its transcript and protein traffickings as a response to the modification of gas composition.…”