Springer-Verlag Wien 2014. Rather than the presence of unique metabolic pathways, it is the absence of many pathways that characterizes the metabolism of Cryptosporidium. In fact, this genus of parasites has lost its ability of synthesizing de novo virtually all nutrients such as amino acids, nucleotides and fatty acids, thus relying on a large number of transporters to scavenge nutrients from the host. Members of this genus lack an apicoplast and associated pathways that are present in other apicomplexans. They lack cytochrome-based respiration, and rely mainly on glycolysis for energy production. Core metabolic pathways are highly streamlined, and redundancy is rare. These features make Cryptosporidium different from other apicomplexans. This chapter summarizes these features based on the analysis of genome sequences and published biochemical data in the context of drug targets and drug development.
