The role of stj fimbrial operon in the intestinal persistence of Salmonella Typhimurium in mice

Abstract

Salmonella Typhimurium contains 13 operons coding for fimbriae with unique binding specificities to host epithelial surfaces. stj operon is only detected in S. Typhimurium genome suggesting that Stj fimbria may effect serovarspecific virulence characteristics. In this study, the role of stj fimbrial operon in the long-term persistence of S. Typhimurium was identified by competitive infection experiment in genetically resistant mouse (CBA) model system. Knock-out mutation of stjA (major subunit of the Stj fimbria) gene reduced recovery of S. Typhimurium from fecal samples and its colonization to spleen, cecum and mesenteric lymph nodes over a 34-day time period (p < 0.05). This data indicate that stj fimbrial operon has a role in long-term intestinal persistence of S. Typhimurium in CBA mice.

Transcriptional Regulation of stj Fimbrial Operon in Salmonella Typhimurium

“…Typhimurium MA2 mutant, with stjE::LacZYA fusion, generated by Akkoç et al (1) was used in activation of stj fimbrial operon via transposon (T-POP) mutagenesis. Expression of stj fimbrial operon by phenotypic characterisation after transduction of T-POP transposon to S. Typhimurium MA2 mutant shows that it harboured the transposase gene.…”

“…Until recently, there has been no information on the role of Stj fimbriae in virulence or persistence of S. Typhimurium in the host systems. Akkoc et al (1) showed that stj fimbrial operon affected colonization and persistence of S. Typhimurium in mouse model systems. Protein sysnthesis patterns obtained from this study also confirmed that Stj fimbriae in S. Typhimurium was expressed in bacteria during infection in the host.…”

“…Protein sysnthesis patterns obtained from this study also confirmed that Stj fimbriae in S. Typhimurium was expressed in bacteria during infection in the host. Among 2500 serotypes, Stj fimbriae is present only in S. Typhimurium strain (1,10). This indicates that determination of regulation characteristics in the stj operon in S. Typhimurium are also essential for the determination of the evolution of the serovars.…”

“…However, no studies existed in current literature indicating the role of this fimbria in virulence and persistence in host systems of S. Typhimurium until 2009. Akkoç et al (1) identified the role of the stj fimbriyal operon in the long-term persistence of S. Typhimurium by competitive infection experiment using a group of four genetically resistant mouse (CBA) model systems. In that study, stj mutant MA44 (phoN + ) and a phoN mutant strain AJB715 (stj + )…”