Difference of MreBCD Complex Interactome in Salmonella Typhimurium ST19 and ST213 Genotypes on Pathogenesis and Stress Response Pathways

Abstract

Background: Salmonella enterica is the etiological agent of salmonellosis, with a high infection rate worldwide in Mexico, ST213 genotype of S. enterica ser. Typhimurium is displacing the ancestral ST19 genotype. Bacterial cytoskeleton protein complex MreBCD plays an important role in S. enterica pathogenesis, but underlying mechanisms are unknown.

Results: In this study, 106 interactions among MreBCD and 15 proteins from S. Typhimurium Pathogenicity Islands 1 (SP-I) and 2 (SP-2) involved in both bacterial virulence and stress response were predicted in ST213 and ST19 genotypes, of which 12 interactions were confirmed in vitro. In addition, gene cluster analysis in 100 S. Typhimurium genomes was performed for these genes.

Results and conclusion: The in silico and in vitro results showed a novel MreBCD interactome involved in regulating pathogenesis and stress response through interactions with virulence factors located at SPI-1 and SPI-2. Furthermore, both pseudogene presence and sequence variations in four tested proteins between genotypes resulted in differential interaction patterns involved in Salmonella motility and survival in eukaryotic cells, which could explain the replacement of ST19 by ST213 in Mexico.

Keywords: Flagella-mediated bacterial motility; RcsC; prokaryotic cytoskeleton; protein prediction interaction; stress response; two-hybrid assay..