Tube graphs representing sporulation of
Cyclospora cayetanensis from Lima, Peru

Experimental design: A sample was strained through a graded series of sieves to an exclusion of 150 micrometers. 150 ml samples were sporulated in 250 ml flasks in 1% aqueous potassium dichromate solution at a sediment to liquid ratio of about 1:10. Three water baths with temperatures of 25 C, 30 C, and 35 C were utilized. Some flasks received bubbled aeration whereas others received no additional aeration and were simply swirled twice daily. Aliquots were removed from each flask at periodic intervals and the first 100 oocysts encountered scored: Non-viable (oocyst contents obviously messed up); dispersed sporont (cytoplasm in oocyst dispersed throughout oocyst and may or may not be viable); sporont (cytoplasm contracted in oocyst); sporoblast (sporocysts beginning to form but contents of sporocysts obviously without sporozoites); sporulated (sporocysts fully formed and look normal).

Conclusions: Oocysts sporulate well at 25 C, and tend to sporulate poorly at 30 C and not at all at 35 C. Bubbling air into cultures does not improve sporulation and may actually interfer with the process, and indeed simply swirling flasks periodically provides adequate aeration for sporulation to occur.