In vitro growth characteristics and morphological differentiation of Leishmania martiniquensis promastigotes in different culture media

The protozoan hemoflagellate, Leishmania martiniquensis, is the causative agent of cutaneous and visceral leishmaniasis among humans. This parasite was first isolated from an autochthonous case of cutaneous leishmaniasis in Martinique Island (French West Indies) in 1995 and its taxonomical position was later established in 2002. At present, the emergence of this globally infectious disease caused by L.martiniquensis raises serious concerns and has gained attention from the national public health policy. Epidemiological studies indicated that Thailand is one of the endemic areas of L.martiniquensis with hundreds of cases, both symptomatic and asymptomatic, have been reported among patients positive for HIV/AIDS. Information on its basic biology including suitable conditions for parasite propagation is limited. To assess this, we used four established media, that is, Medium 199 (M199), RPMI 1640 medium (RPMI), Grace's insect medium (GIM), and Schneider's insect medium (SIM) to investigate the promastigote growth by evaluating the growth characteristics, viability, and kinetics of stage differentiation in each medium. The findings from this study showed that parasites growing in different media exhibited different biological characteristics, which would be suitable for very specific research purposes, i.e., RPMI; for long term parasite maintenance, M199; for mass culture of parasites, M199 and GIM; for initial isolation of the parasites in clinical specimens, and SIM; for metacyclogenesis study.