With the World Health Organization reporting over 30,000 deaths and 200-400,000 new cases annually, visceral Leishmaniasis is a serious disease affecting some of the world's poorest people. As drug resistance continues to rise, there is a huge unmet need to improve treatment. Miltefosine remains one of the main treatments for Leishmaniasis, yet its mode of action (MoA) is still unknown. Underst...

Monoclonal antibodies were produced against gamma-irradiated amastigotes of Leishmania major. Five antibodies (T16 through T20) were selected which reacted in enzyme-linked immunoassays with the intracellular stage of the parasite. These antibodies did not react with promastigotes of L. major or Leishmania donovani. One of the monoclonal antibodies (T16) reacted with amastigotes of Leishmania m...

Amoebae of Dictyostelium discoideum produce tracks with two distinct morphologies on gold-coated coverslips. The wild-type strain and other strains that feed only by phagocytosis produced indistinct, fuzzy tracks, whereas mutants capable of axenic growth produced clear, sharp tracks. The sharp track morphology was found to be a recessive phenotype that segregates with axenicity and probably req...

We determined the surface-associated proteolytic activity in three Entamoeba histolytica Schaudinn, 1903 strains (monoxenic HM1, axenic HM1, and HK9) of known virulence and its relationship with collagenase activity. Both activities were also determined in axenic HM1 amoebae trophozoites which were sensitive and resistant to complement-mediated lysis. Surface proteolytic activity was determined...

The ability to manipulate the Leishmania genome to create genetically modified parasites by introducing or eliminating genes is considered a powerful alternative for developing a new generation vaccine against leishmaniasis. Previously, we showed that the deletion of one allele of the Leishmania infantum silent information regulatory 2 (LiSIR2) locus was sufficient to dramatically affect amasti...

Leishmaniasis constitutes a complex of diseases with clinical and epidemiological diversity and includes visceral leishmaniasis, a disease that is fatal when left untreated. In earlier studies, the authors reported that Aloe vera leaf exudate (AVL) is a potent antileishmanial agent effective in promastigotes of Leishmania braziliensis, Leishmania mexicana, Leishmania tropica, Leishmania major a...

The Leishmania major aquaglyceroporin, LmAQP1, is responsible for the transport of antimonite [Sb(III)], an activated form of Pentostam or Glucantime. Downregulation of LmAQP1 provides resistance to trivalent antimony compounds and increased expression of LmAQP1 in drug-resistant parasites can reverse the resistance. Besides metalloid transport, LmAQP1 is also permeable to water, glycerol, meth...

Host-directed therapies (HDTs) constitute promising alternatives to traditional therapy that directly targets the pathogen but is often hampered by pathogen resistance. HDT could represent a new treatment strategy for leishmaniasis, a neglected tropical disease caused by the obligate intracellular parasite Leishmania. This protozoan develops exclusively within phagocytic cells, where infection ...

To survive extremely different environments, intracellular parasites require highly adaptable physiological and metabolic systems. Leishmania donovani extracellular promastigotes reside in a glucose-rich, slightly alkaline environment in the sand fly vector alimentary tract. On entry into human macrophage phagolysosomes, promastigotes differentiate into intracellular amastigotes. These cope wit...

Recently, our group isolated and reported the antiproliferative activity in promastigotes and axenic amastigote forms of Leishmania amazonensis treated with 5-methyl-2,2':5',2″-terthiophene (compound A) and 5'-methyl-[5-(4-acetoxy-1-butynyl)]-2,2'-bi-thiophene (compound B) isolated from the aerial parts of Porophyllum ruderale. Here, we demonstrated that both compounds exhibited activity agains...