Relationship Between the Tat Protein Transport System and Virulence of Enterotoxigenic Escherichia Coli

Abstract Background We aimed to investigate the effect of Tat deletion on the pathogenicity of enterotoxigenic Escherichia coli (ETEC). Changes in bacterial dynamics and virulence after deletion were examined using mobility and animal toxicity tests for ETEC. Further, differential expression of proteins between the gene-deletion and wild-type strains was analyzed using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to explore the possible mechanisms underlying the effects of this gene on bacterial virulence. Results After Tat knockout, the virulence of ETEC10407 was strongly attenuated, and its invasion in rabbit intestinal mucosa was significantly reduced. Mass spectrometry revealed that 17 differentially expressed proteins involved in physiological functions of bacteria, such as virulence and substance or energy metabolism might affect bacterial pathogenicity. Conclusions The Tat protein transport system of ETEC is closely related to its virulence.