Methylthioadenosine Suppresses Salmonella Virulence.


Journal Article

In order to deploy virulence factors at appropriate times and locations, microbes must rapidly sense and respond to various metabolite signals. Previously, we showed a transient elevation of the methionine-derived metabolite methylthioadenosine (MTA) concentration in serum during systemic Salmonella enterica serovar Typhimurium infection. Here we explored the functional consequences of increased MTA concentrations on S Typhimurium virulence. We found that MTA, but not other related metabolites involved in polyamine synthesis and methionine salvage, reduced motility, host cell pyroptosis, and cellular invasion. Further, we developed a genetic model of increased bacterial endogenous MTA production by knocking out the master repressor of the methionine regulon, metJ Like MTA-treated S Typhimurium, the ΔmetJ mutant displayed reduced motility, host cell pyroptosis, and invasion. These phenotypic effects of MTA correlated with suppression of flagellar and Salmonella pathogenicity island 1 (SPI-1) networks. S Typhimurium ΔmetJ had reduced virulence in oral and intraperitoneal infection of C57BL/6J mice independently of the effects of MTA on SPI-1. Finally, ΔmetJ bacteria induced a less severe inflammatory cytokine response in a mouse sepsis model. Together, these data indicate that exposure of S Typhimurium to MTA or disruption of the bacterial methionine metabolism pathway suppresses S Typhimurium virulence.

Full Text

Duke Authors

Cited Authors

  • Bourgeois, JS; Zhou, D; Thurston, TLM; Gilchrist, JJ; Ko, DC

Published Date

  • September 2018

Published In

Volume / Issue

  • 86 / 9

PubMed ID

  • 29866910

Pubmed Central ID

  • 29866910

Electronic International Standard Serial Number (EISSN)

  • 1098-5522

International Standard Serial Number (ISSN)

  • 0019-9567

Digital Object Identifier (DOI)

  • 10.1128/IAI.00429-18


  • eng