Escherichia coli mediated resistance of Entamoeba histolytica to oxidative stress is triggered by oxaloacetate

PLoS Pathog. 2018 Oct 11;14(10):e1007295. doi: 10.1371/journal.ppat.1007295. eCollection 2018 Oct.


Amebiasis, a global intestinal parasitic disease, is due to Entamoeba histolytica. This parasite, which feeds on bacteria in the large intestine of its human host, can trigger a strong inflammatory response upon invasion of the colonic mucosa. Whereas information about the mechanisms which are used by the parasite to cope with oxidative and nitrosative stresses during infection is available, knowledge about the contribution of bacteria to these mechanisms is lacking. In a recent study, we demonstrated that enteropathogenic Escherichia coli O55 protects E. histolytica against oxidative stress. Resin-assisted capture (RAC) of oxidized (OX) proteins coupled to mass spectrometry (OX-RAC) was used to investigate the oxidation status of cysteine residues in proteins present in E. histolytica trophozoites incubated with live or heat-killed E. coli O55 and then exposed to H2O2-mediated oxidative stress. We found that the redox proteome of E. histolytica exposed to heat-killed E. coli O55 is enriched with proteins involved in redox homeostasis, lipid metabolism, small molecule metabolism, carbohydrate derivative metabolism, and organonitrogen compound biosynthesis. In contrast, we found that proteins associated with redox homeostasis were the only OX-proteins that were enriched in E. histolytica trophozoites which were incubated with live E. coli O55. These data indicate that E. coli has a profound impact on the redox proteome of E. histolytica. Unexpectedly, some E. coli proteins were also co-identified with E. histolytica proteins by OX-RAC. We demonstrated that one of these proteins, E. coli malate dehydrogenase (EcMDH) and its product, oxaloacetate, are key elements of E. coli-mediated resistance of E. histolytica to oxidative stress and that oxaloacetate helps the parasite survive in the large intestine. We also provide evidence that the protective effect of oxaloacetate against oxidative stress extends to Caenorhabditis elegans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amebiasis / drug therapy
  • Amebiasis / metabolism
  • Amebiasis / parasitology
  • Animals
  • Caenorhabditis elegans / drug effects
  • Caenorhabditis elegans / growth & development
  • Caenorhabditis elegans / parasitology
  • Cells, Cultured
  • Entamoeba histolytica / drug effects*
  • Entamoebiasis / drug therapy*
  • Entamoebiasis / metabolism
  • Entamoebiasis / parasitology
  • Escherichia coli / physiology*
  • HeLa Cells
  • Humans
  • Intestine, Large / drug effects
  • Intestine, Large / metabolism
  • Intestine, Large / parasitology
  • Macrophages / cytology
  • Macrophages / drug effects
  • Macrophages / parasitology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred CBA
  • Oxaloacetic Acid / pharmacology*
  • Oxidative Stress / drug effects*
  • Protozoan Proteins / metabolism*


  • Protozoan Proteins
  • Oxaloacetic Acid

Grant support

This study was supported by the Israel Ministry of Health within the framework ERA-NET Infect-ERA (031L0004) (AMOEBAC project) and grants from the Israel Science Foundation (ISF) (260/16), Rappaport Institute, and U.S.-Israel Binational Science Foundation (BSF) (2015211) to SA, the German Ministry of Education and Science BMBF within the framework ERA-NET Infect-ERA (031L0004) (AMOEBAC project) to ML, the Israeli Centers of Research Excellence (I-CORE) program (Center No. 1796/12) and Israel Cancer Research Fund to ATL, the Grants-in-Aid for International Scientific Research (B) from JSPS (15H05274) and Grants-in-Aid for Scientific Research (C) (15K08441) to HH, Grant-in Aid for Young Scientists (B) from Ministry of Education, Culture, Sports, Science, and Technology (26870849), scientific grants from the Ohyama Health Foundation, the Ichiro Kanehara Foundation, and the Takeda Science Foundation to CS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.