Complete genome sequence of the apicomplexan, Cryptosporidium parvum

Science. 2004 Apr 16;304(5669):441-5. doi: 10.1126/science.1094786. Epub 2004 Mar 25.


The apicomplexan Cryptosporidium parvum is an intestinal parasite that affects healthy humans and animals, and causes an unrelenting infection in immunocompromised individuals such as AIDS patients. We report the complete genome sequence of C. parvum, type II isolate. Genome analysis identifies extremely streamlined metabolic pathways and a reliance on the host for nutrients. In contrast to Plasmodium and Toxoplasma, the parasite lacks an apicoplast and its genome, and possesses a degenerate mitochondrion that has lost its genome. Several novel classes of cell-surface and secreted proteins with a potential role in host interactions and pathogenesis were also detected. Elucidation of the core metabolism, including enzymes with high similarities to bacterial and plant counterparts, opens new avenues for drug development.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antiprotozoal Agents / pharmacology
  • Carbohydrate Metabolism
  • Cryptosporidium parvum / genetics*
  • Cryptosporidium parvum / metabolism*
  • Cryptosporidium parvum / pathogenicity
  • Cryptosporidium parvum / physiology
  • DNA, Protozoan / genetics
  • Drug Resistance / genetics
  • Enzymes / genetics
  • Enzymes / metabolism*
  • Ethanol / metabolism
  • Genes, Protozoan
  • Genome, Protozoan*
  • Glycolysis
  • Introns
  • Mitochondria / genetics
  • Molecular Sequence Data
  • Multigene Family
  • Open Reading Frames
  • Organelles / genetics
  • Protozoan Proteins / chemistry
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism*
  • Purines / metabolism
  • Sequence Analysis, DNA
  • Transcription, Genetic


  • Antiprotozoal Agents
  • DNA, Protozoan
  • Enzymes
  • Protozoan Proteins
  • Purines
  • Ethanol