Quantitative study of the Escherichia coli (EHEC) O157:H7 proteome

ZHONGJIAN CHEN; LARZABAL MARIANO; AMIGO NATALIA; AMADIO ARIEL FERNANDO; CATALDI ANGEL; SILVA M WANDERSON; QI ZHANG; JINLONG BEI

Florencia

Congreso; VTEC 2018; 2018

Enterohemorragic Escherichia coli (EHEC O157:H7) is a human patogeno responsible for diarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS). The infection by EHEC is widely distributed in the world and numerous outbreak of enterohemorragic disease were reported. In industrialized countries Hus is reported as a disease of low incidence. On the other hand, Argentina is considerate the country with the highest HUS incidence in the world. Proteomic studies show that absolute quantitation of proteins presents with in a complex proteins mixture is extremely important for understand physiological adaptation in response to biological demands promoted by environmental changes. Thus in this studio, to promote insight into the molecular basis of EHEC O157:H7 physiology and pathogenesis, we combined the proteomic data set of three EHEC O157:H7 isolates, used iTRAQ-based quantitative proteomic and emPAI approach to estimate the absolute abundance of EHEC proteome.EHEC O157:H7 strains Rafaela II (clade 8) and Anguil 7.1 (clade 6) isolated from cattle in Argentina and the standard EDL933 (clade 3) recovered from an hamburger in USA were grow in Dulbecco?s modified Eagle?s medium to exponential phase (OD 600nm= 0.6) al 37°C under a 5% CO2 atmosphere. Two biological replicates of whole bacterial lisates of each strain were enzymatically digested with trypsin, pooled and posteriorly labeled with 6-plex iTRAQ reagents. Finally the triptic fragment generates were subyected to proteomic analysis by 2D-LC MS/MS analysis.From this proteomic analysis we identified 2,234 non-redundant protein of EHEC O57:H7. When compared this results with in silico data of EHEC O157:H7 genome was characterized approximately 40% of the proteome predicted this pathogen. The most abundant proteins are involved in the translation process. Kegg enrichment analysis revealed that Glycolysis/ Gluconeogenesis were the metabolic pathway more significant. On the other hand the less abundant are related to DNA process. Among the protein that composed the Type III Secretion System the more abundant protein were EspA, EspB, Tir receptor and Intimin.The result obtained to data show important protein that might contribute both physiology and pathogenicity of EHEC O157:H7.