Open AccessThe Pseudomonas aeruginosa PA14 type III secretion system is expressed but not essential to virulence in the Caenorhabditis elegans – P. aeruginosa pathogenicity model
Author(s) -
Wareham David W.,
Papakonstantinopoulou Anastasia,
Curtis Michael A.
Publication year - 2005
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/j.femsle.2004.11.018
Subject(s) - virulence , caenorhabditis elegans , pseudomonas aeruginosa , biology , type three secretion system , microbiology and biotechnology , mutant , secretion , wild type , effector , gene , genetics , bacteria , biochemistry
The Pseudomonas aeruginosa type III secretion system (TTSS), enabling direct injection of toxins into host cells, has been shown to be crucial to virulence in several models of P. aeruginosa pathogenesis. Using the strain PA14 and its isogenic mutant, PA14 exsA , we investigated the role of the TTSS during infection of the nematode Caenorhabditis elegans . Although C. elegans N2 was killed by PA14 in an infection like process over 48 to 72 h the same effect was observed following infection with PA14 exsA , implying that a functional TTSS was not essential for virulence. This was despite the TTSS being actively expressed during C. elegans infection as demonstrated by the use of green fluorescent reporter constructs and RT‐PCR. However, compared to the wild type PA14, PA14 exsA did display a reduced rate of killing of C. elegans strain AU1 which harbours a mutation in the sek‐1 gene encoding a MAP kinase involved in nematode innate immunity. A fuller understanding of the mechanism of resistance to type III attack in C. elegans may lead to the identification and development of novel therapeutic targets affording protection to TTSS products in man.