An important NK-cell inhibition with reduced TNF-α, IFN-γ and TLR2 expression had previously been identified in patients with diffuse cutaneous leishmaniasis (DCL) infected with Leishmania mexicana. In an attempt to pinpoint alterations in the signaling pathways responsible for the NK-cell dysfunction in patients with DCL, this study aimed at identifying differences in the NK-cell response towa...

Three of thirteen Oryzomys acritus, Emmons and Patton 2005 (Rodentia: Muridae: Sigmodontinae) and 3 of 17 Oryzomys nitidus, Thomas 1884, collected from Noël Kempff National Park, Bolivia, from 2002 to 2005, tested positive for Leishmania (Leishmania) amazonensis or L. (L.) mexicana and negative for Leishmania (Viannia) spp. using the polymerase chain reaction (PCR). Based on previous records of...

Low levels of dehydroepiandrosterone (DHEA) and cortisol hormones produced by the suprarenal cortex have been associated with diseases involving chronic inflammation, low interferon (IFN)-gamma, and high interleukin (IL)-6. Diffuse cutaneous leishmaniasis (DL), a long-lasting intracellular parasitic infectious disease, can spread unknown levels of DHEA and cortisol. Serum concentrations of both...

A molecular epidemiological study was performed using FTA card materials directly sampled from lesions of patients with cutaneous leishmaniasis (CL) in the state of Lara, Venezuela, where causative agents have been identified as Leishmania (Viannia) braziliensis and L. (Leishmania) venezuelensis in previous studies. Of the 17 patients diagnosed with CL, Leishmania spp. were successfully identif...

American tegumentary leishmaniasis is caused by a diverse group of Leishmania classified within two species complexes: L. mexicana and L. braziliensis. Because distinct disease forms are associated with certain species or subspecies, prognosis requires taxonomic identification of the pathogen. Biological criteria allow identification only to the species level; thus, biochemical and immunologica...

A countrywide epidemiological study was performed to elucidate the current geographic distribution of causative species of cutaneous leishmaniasis (CL) in Ecuador by using FTA card-spotted samples and smear slides as DNA sources. Putative Leishmania in 165 samples collected from patients with CL in 16 provinces of Ecuador were examined at the species level based on the cytochrome b gene sequenc...

Leishmania species are the causative agents of the leishmaniases, a spectrum of neglected tropical diseases. Amastigote stage parasites exist within macrophages and scavenge host factors for survival, for example, Leishmania species utilise host sphingolipid for synthesis of complex sphingolipid. In this study L. mexicana endocytosis was shown to be significantly upregulated in amastigotes, ind...

A 19-month mark-release-recapture study of Neotoma micropus with sequential screening for Leishmania mexicana was conducted in Bexar County, Texas, USA. The overall prevalence rate was 14.7% and the seasonal prevalence rates ranged from 3.8 to 26.7%. Nine incident cases were detected, giving an incidence rate of 15.5/100 rats/year. Follow-up of 101 individuals captured two or more times ranged ...

Twenty-eight white-throated woodrats (Neotoma albigula) collected in Pima County, Arizona were screened for Leishmania using culture and the polymerase chain reaction (PCR). Two rodents were culture positive. Isoenzyme analysis determined the isolates to be Leishmania mexicana. The two culture-positive and four additional rodents were determined to be Leishmania-positive by the PCR. These isola...

Leishmania parasites cause human cutaneous, mucocutaneous and visceral leishmaniasis. Several studies proposed involvement of certain genes in infectivity of these parasites based on differential mRNA expression data. Due to unusual gene expression mechanism, functions of such genes must be further validated experimentally. Here, we investigated a role of one of the putative virulence factors, ...