Partial anaerobiosis induces infectivity of Leishmania infantum promastigotes

Abstract

Leishmania infantum stationary-phase promastigotes could acquire infectivity via preincubation in a partially anaerobic medium (95% air/5% CO₂) for 16 h before the infection, whereas promastigotes were efficiently destroyed when no CO₂ was present. Incubation of L. infantum promastigotes with additional glucose (20 and 50 mM) greatly increased infection parameters in the absence of CO₂; this is consistent with a “reverse Pasteur effect.” Results showed that culture at 33 °C permitted survival and amastigote multiplication (a nearly 10-fold increase in amastigotes as compared with those observed in 37 °C cultures). This finding was obtained with the two strains of L. infantum tested (Doba and PB75).