ZFIN ID: ZDB-PUB-110317-28
A Mycobacterium marinum TesA mutant defective for major cell wall associated lipids is highly attenuated in Dictyostelium discoideum and zebrafish embryos
Alibaud, L., Rombouts, Y., Trivelli, X., Burguière, A., Cirillo, S.L., Cirillo, J.D., Dubremetz, J.F., Guérardel, Y., Lutfalla, G., and Kremer, L.
Date: 2011
Source: Molecular Microbiology   80(4): 919-934 (Journal)
Registered Authors: Lutfalla, Georges
Keywords: Mycobacterium marinum, Dictyostelium, virulence, TesA, zebrafish, notochord
MeSH Terms:
  • Animals
  • Cell Wall/enzymology*
  • Cells, Cultured
  • DNA Transposable Elements
  • Dictyostelium/microbiology*
  • Glycolipids/deficiency*
  • Glycolipids/genetics
  • Lipids/deficiency*
  • Lipids/genetics*
  • Macrophages/microbiology
  • Mutation
  • Mycobacterium Infections/genetics
  • Mycobacterium Infections/metabolism
  • Mycobacterium Infections/pathology
  • Mycobacterium marinum/enzymology*
  • Mycobacterium marinum/genetics
  • Notochord/microbiology
  • Palmitoyl-CoA Hydrolase/genetics
  • Palmitoyl-CoA Hydrolase/metabolism*
  • Zebrafish/embryology
  • Zebrafish/microbiology*
PubMed: 21375593 Full text @ Mol. Microbiol.
Infection of the zebrafish with Mycobacterium marinum is regarded as a well established experimental model to study of the pathogenicity of Mycobacterium tuberculosis. Herein, a M. marinum transposon mutant library was screened for attenuated M. marinum phenotypes using a Dictyostelium discoideum assay. In one attenuated mutant the transposon was located within tesA, encoding a putative type II thioesterase. Thin layer chromatography analyses indicated that the tesA::Tn mutant failed to produce two major cell wall-associated lipids. Mass spectrometry and nuclear magnetic resonance clearly established the nature of missing lipids as phthioglycol diphtioceranates and phenolic glycolipids, respectively, indicating that TesA is required for the synthesis of both lipids. When injected into the zebrafish embryo bloodstream, the mutant was found to be highly attenuated, thus validating the performance and relevance of the Dictyostelium screen. Consistent with these in vivo findings, tesA::Tn exhibited increased permeability defects in vitro, which may explain its failure to survive in host macrophages. Unexpectedly, virulence was retained when bacteria were injected into the notochord. Histological and ultrastructural studies of the infected notochord revealed the presence of actively-proliferating mycobacteria, leading to larval death. This work presents for the first time the notochord as a compartment highly susceptible to mycobacterial infection.