Leishmania spp.: Completely defined medium without serum and macromolecules (CDM/LP) for the continuous in vitro cultivation of infective promastigote forms

The elimination of serum or of serum-derived macromolecules that supplant t he fetal calf serum requirement from Leishmania culture media could decreas e costs and improve the feasibility of large-scale production of well-defin ed parasite material. We report a completely defined medium, without serum- derived protein and/or macromolecules as a serum substitute, of common, ava ilable, and inexpensive constituents that can be used in place of serum-sup plemented media for the continuous in vitro cultivation of promastigote for ms of various Leishmania species. Typical promastigote morphology was obser ved in Giemsa-stained smears, regardless of the strain analyzed. Electropho retic analysis showed that the proteinase patterns of aserically grown prom astigote forms were similar to those obtained in serum-supplemented RPMI 16 40 medium for all Leishmania studied. Similar antigenic profiles were recog nized in immunoblots by sera from hosts with visceral or cutaneous leishman iasis after growing promastigotes in the two different culture media. For p arasites causing both cutaneous and visceral leishmaniasis, the absence of serum and macromolecules in the culture medium did not markedly change thei r in vitro infectivity for resident mouse macrophages and their virulence i n animals compared with parasites cultivated in nondefined medium. Serum-fr ee technology will be increasingly important in providing stability and rep roducibility as research using promastigote moves closer to therapeutic app lications.