Aim: To establish a method for continuously cultivating a large number of P. falciparum gametocytes in vitro using carbon dioxide incubator.
Methods: The number of gametocytes produced in experimental and control groups was compared after the addition of various concentrations of NaHCO3 to the culture medium.
Results: The gametocytes began to rise on day 5 of cultivation and reached a peak on day 11-13. The peak gametocyte loads were 1.9% +/- 0.6% and 1.3% +/- 0.4% (P < 0.05) in experimental and control group, respectively, indicating that the complete medium with 30 mmol/L sodium bicarbonate was beneficial to gametogenesis. The numbers of stages I-V gametocytes rose to a peak on d5, d7, d11, d13 and d15, respectively. On day 15 the percentage of stage V gametocytes was 7.1%-52.6% with an average of 24.3%. The ratio of macrogametocyte to microgametocyte was 12.8:1. The parasites were able to produce high gametocytaemia up to 24th subculture after thawing. Laboratory reared Anopheles stephensi fed through membrane on blood infected with P. falciparum were dissected, no oocyst was found in the midgut.
Conclusion: A culture system which could consistently and stably produce a large number of gametocytes of P. falciparum was established.