Plasmid replication initiator protein TrfA represses the host type III secretion system in <i>Pseudomonas aeruginosa</i>.

ABSTRACT: Pseudomonas aeruginosa is an environmental bacterium and opportunistic human pathogen capable of causing a wide range of infections in humans. The type III secretion system (T3SS) plays a key role in the pathogenesis of acute P. aeruginosa infections. Expression of the T3SS is controlled by a master activator ExsA, whose transcription is driven by its operon promoter P_exsC as well as its own promoter P_exsA. Here, we found that plasmid replication initiation protein TrfA acts as a repressor for the T3SS gene expression in P. aeruginosa. Production of the TrfA reduced the expression of the T3SS genes and the bacterial pathogenicity in a mouse acute pneumonia model. Further analysis revealed that the expression of trfA resulted i

SUBMITTER: Zhang Y 

PROVIDER: S-EPMC12691604 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature