In vitro differentiation of Wuchereria bancrofti (Filariidae)

Wuchereria bancrofti microfilariae were isolated from blood of infected individuals and cultured in vitro under several conditions. RPMI 1640 and TC-199 media supplemented with fetal or human serum were able to support the microfilariae for periods up to 35 days at 37 degrees C (viability greater than 85%). In contrast, in minimal essential medium the microfilariae did not survive for more than 48 h. In cultures kept at 28 degrees C, where viability was much lower (approximately 10% on day 15), microfilariae differentiated into type IV larvae ("sausage" form). The in vitro maintainance of microfilarial larval forms is particularly important in the case of W. bancrofti due to the absence of an experimental model for the disease.