Comparative biochemistry of Giardia, Hexamita and Spironucleus: Enigmatic diplomonads

- Diplomonads: diverse free-living/parasitic flagellates inhabiting low-O2 locations.
- Typically found in anaerobic water columns, sediments, animal and fish intestines.
- Life cycles usually include an encysted stage resistant to harsh conditions.
- Biochemical characteristics of anaerobic and encysted stages provide drug targets.
- Metronidazole restrictions urgently require alternatives: synthetic or plant derived.