Serial passage of axenically-cultured Leishmania chagasi promastigotes results in a progressive diminution in resistance to complement mediated lysis (CML), whereas high CML resistance is seen in infectious metacyclic promastigotes from the sandfly vector as well as metacyclic-like promastigotes within low passage cultures at stationary growth phase. As previously reported [94], in a screen see...

We comment on the problems faced by Niscola et al1 during a specific diagnosis of leishmaniasis in patients with hematological malignancies. Rather than a serological test like direct agglutination and anti-K39 antibody, an in-vitro culture, and/or polymerase chain reaction (PCR) might be required to establish leishmaniasis diagnosis in those with a concurrent HIV infection. Serology would gene...

The obligate intracellular pathogen Leishmania major survives and multiplies in professional phagocytes. The evasion strategy to circumvent killing by host phagocytes and establish a productive infection is poorly understood. Here we report that the virulent inoculum of Leishmania promastigotes contains a high ratio of annexin A5-binding apoptotic parasites. This subpopulation of parasites is c...

Experimental infections with visceral Leishmania spp. are frequently performed referring to stationary parasite cultures that are comprised of a mixture of metacyclic and non-metacyclic parasites often with little regard to time of culture and metacyclic purification. This may lead to misleading or irreproducible experimental data. It is known that the maintenance of Leishmania spp. in vitro re...

Infection by vector-borne protozoa of the genus Leishmania occurs by the deposition of parasites within the skin of the mammalian host, where they eventually bind to and are phagocytized by Mphis. Our previous work supported the idea that parasites can interact with extracellular matrix and basement membrane proteins, such as fibronectin (FN), within the skin, leading to enhanced invasion. In t...

This study investigated whether Leishmania species, the etiologic agent of cutaneous (Leishmania major) and visceral (Leishmania donovani) leishmaniasis, could differentially elicit early inflammatory events in vivo correlating with the subsequent development of their reciprocal pathogenesis. By use of the murine air pouch system, injection of Leishmania led to a rapid and transient accumulatio...

The effect of ergosterol depletion by ketoconazole on the leishmanicidal activity of the pore-forming antibiotic amphotericin B (AmB) was investigated. Leishmania mexicana promastigotes were lysed within minutes by the addition of micromolar concentrations of AmB (0.5 microM) but became insensitive to AmB after growth in the presence of ketoconazole (0.25 microM, 90 h). Lipid chromatographic an...

background: pteridine metabolic pathway is unusual features of leishmania , which is necessary for the growth of parasite. leishmania has evolved a complex and versatile pteridine salvage network which has the ability of scavenging a wide area of the conjugated and unconjugated pteridines espe-cially folate and biopterin. in this study, we focus on the inhibition of ptr1 gene expression. method...

Previous works demonstrated that various species of Leishmania promastigotes exhibit differential sensitivity to complement-mediated lysis (CML) during development. Upon exposure to normal human serum (NHS), cultures of Leishmania chagasi promastigotes recently isolated from infected hamsters (fewer than 5 in vitro passages) are CML-sensitive when in the logarithmic growth phase but become CML-...