Quantification of enterohemorrhagic Escherichia coli O157:H7 protein abundance by high-throughput proteome

Abstract

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a human pathogen responsible fordiarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS). To promote a comprehensiveinsight into the molecular basis of EHEC O157:H7 physiology and pathogenesis,the combined proteome of EHEC O157:H7 strains, Clade 8 and Clade 6 isolated from cattlein Argentina, and the standard EDL933 (clade 3) strain has been analyzed. From shotgunproteomic analysis a total of 2,644 non-redundant proteins of EHEC O157:H7 were identified,which correspond approximately 47% of the predicted proteome of this pathogen. Normalizedspectrum abundance factor analysis was performed to estimate the proteinabundance. According this analysis, 50 proteins were detected as the most abundant ofEHEC O157:H7 proteome. COG analysis showed that the majority of the most abundantproteins are associated with translation processes. A KEGG enrichment analysis revealedthat Glycolysis / Gluconeogenesis was the most significant pathway. On the other hand, theless abundant detected proteins are those related to DNA processes, cell respiration andprophage. Among the proteins that composed the Type III Secretion System, the mostabundant protein was EspA. Altogether, the results show a subset of important proteins thatcontribute to physiology and pathogenicity of EHEC O157:H7.