Two proteins presented orthologs highly distributed in various bacterial pathogens: (i) a putative iron transport Compound C datasheet system binding (secreted) protein [GenBank:ADL10460]; and (ii) a putative glycerophosphoryl diester phosphodiesterase [GenBank:ADL11410]. Interestingly, an ortholog of this latter protein was included recently in a list of seventeen proteins found to be very common in pathogenic bacteria and absent or very uncommon in non-pathogens, representing then probable virulence-associated factors [72]. In fact, reports in the literature can be found that associate orthologs of the two aforementioned proteins with virulence phenotypes [73, 74]. Noteworthy, both

proteins were detected in this study only in the exoproteome of the C231 strain of C. pseudotuberculosis, the more virulent one. Conclusions There seems to be a growing interest in profiling the exoproteomes of

bacterial pathogens, due to the distinguished roles played by exported proteins on host-pathogen interactions [10]. Classical proteomic profiling strategies, normally involving two-dimensional (2D) gel electrophoresis, have been extensively used for this purpose [16–20]. Nevertheless, the introduction of more high-throughput proteomic technologies brings new perspectives to the study of bacterial exoproteomes, Trichostatin A cell line as it makes it easier to analyze multiple phenotypically distinct strains, yielding better subproteome coverage Cyclin-dependent kinase 3 with fewer concerns regarding technical sensitivity and reproducibility [75]. Besides, the currently available methods for label-free

quantification of proteins [76] allow us to compare the “”LCZ696 order dynamic behavior”" of the exoproteome across different bacterial strains, and this in turn will help us to better identify alterations of the exoproteome that may contribute to the various virulence phenotypes. By using a high-throughput proteomic strategy, based on a recently introduced method of LC-MS acquisition (LC-MSE) [14], we were able to perform a very comprehensive analysis of the exoproteome of an important veterinary pathogen, Corynebacterium pseudotuberculosis. Comparative exoproteome analysis of two strains presenting different virulence status allowed us to detect considerable variations of the core C. pseudotuberculosis extracellular proteome, and thereby the number of exoproteins identified increased significantly. Most importantly, it was helpful to gain new insights into the probable participation of C. pseudotuberculosis exported proteins, other than the well-known PLD and FagB, in the virulence of this bacterium. Several novel targets for future work on C. pseudotuberculosis molecular determinants of virulence can be identified from the catalogue of exoproteins generated in this study. Interestingly, around 30% of the proteins identified were predicted by the SurfG+ software [15] as being probably surface exposed in C. pseudotuberculosis.