Cell lysates from 16 strains of eight Leishmania species were used to test haemagglutination activity (HA) against a variety of RBC. HA was detected using native or neuraminidase-treated rabbit RBC; it was found in promastigotes of all the Leishmania strains tested and in axenic amastigotes of L. mexicana. The HA was trypsin-sensitive, heat-resistant and partially dependent on divalent cations....

OBJECTIVES Cutaneous leishmaniasis is a common parasitic disease which is endemic in some parts of the world. In vitro and in vivo studies have shown azithromycin efficacy on some Leishmania species. Because of structural similarity between clarithromycin and azithromycin and efficacy of clarithromycin against intracellular organisms and due to the absence of previous studies in this respect, w...

To mimic the sandfly pool feeding process and characterize the cellular and biochemical events that occur during the early stages of promastigote-host interaction, we developed an ex vivo model of human blood infection with Leishmania promastigotes. Within 30 s of blood contact, Leishmania promastigotes bind natural anti-Leishmania antibodies, which then activate the classical complement pathwa...

Kinetoplastid membrane protein-11 (KMP-11), a protein present in all kinetoplastid protozoa, is considered a potential candidate for a leishmaniasis vaccine. A suitable leishmaniasis vaccine candidate molecule must be expressed in amastigotes, the infective stage for mammals. However, the expression of KMP-11 in Leishmania amastigotes has been a subject of controversy. We evaluated the expressi...

Leishmaniasis is initiated when sandflies inject the extracellular promastigote form of the parasite into the skin. Promastigotes are rapidly phagocytized, after which they transform into the intracellular amastigote form. The multiplication of the latter within macrophages leads to clinical disease. Treatment of leishmaniasis is primarily with pentavalent antimonials, parenteral and potentiall...

Leishmaniases are diseases caused by protozoa of the genus Leishmania that affect more than 20 million people in the world. The initial phase of the infection is fundamental for either the progression or control of the disease. The Leishmania parasites are injected in the skin as promastigotes and then, after been phagocytized by the host macrophages, rapidly transform into amastigotes. In this...

This work aims at identifying an effective protocol to raise anti-Leishmania chagasi amastigote antibodies in different animal species. Protocols of immunization by subcutaneous injections of L. chagasi promastigote and amastigote lysates or by either intravenous or subcutaneous inoculation of live metacyclic promastigotes were assessed in mice, rabbits, and dogs. The immunization with live pro...

We have set up an assay to study the interactions of live pathogens with their hosts by using protein and glycosaminoglycan arrays probed by surface plasmon resonance imaging. We have used this assay to characterize the interactions of Leishmania promastigotes with ~70 mammalian host biomolecules (extracellular proteins, glycosaminoglycans, growth factors, cell surface receptors). We have ident...

Allopurinol ribonucleoside [4-hydroxy-1-P-D-ribofuranosylpyrazolo(3,4,-d)pyrimidine] was shown to be more effective than allopurinol in inhibiting the growth of Leishmania promastigotes in vitro. Both allopurinol and its ribonucleoside were equally effective in preventing the transformation of the intracellular form (amastigote) of Leishmania donovani to the extracellular form (promastigote). P...

Surface phosophoglycans such as lipophosphoglycan (LPG) or proteophosphoglycan (PPG) and glycosylinositol phospholipids (GIPLs) modulate essential interactions between Leishmania and mammalian macrophages. Phosphoglycan synthesis depends on the Golgi GDP-mannose transporter encoded by LPG2. LPG2-null (lpg2(-)) Leishmania major cannot establish macrophage infections or induce acute pathology, wh...