The protozoan Crithidia acanthocephali contains, within a modified region of a mitochondrion, a mass of DNA known as kinetoplast DNA (kDNA). This DNA consists mainly of an association of approximately 27,000 covalently closed 0.8-mum circular molecules which are apparently held together in a definite ordered manner by topological interlocking. After culturing of C. acanthocephali cells for 25 g...

The order Kinetoplastida is composed of several families of flagellated protozoa which are among the most ancient of the eukaryotes. The most prominent members of this order are parasites that are responsible for major tropical diseases. These parasites include Trypanosoma brucei, the African trypanosome; Trypanosoma cruzi, the South American trypanosome; and several species of Leishmania. Othe...

Cutaneous leishmaniasis is a common skin disease caused by leishmania parasite. An accurate diagnosis of parasites species is possible using molecular techniques. This study was carried out to compare internal transcribed spacer (ITS1) and kinetoplast deoxyribonucleic acid (KDNA) genes for identifying Leishmania species by Polymerase Chain Reaction (PCR), furthermore, genetic diversity of isola...

This study evaluated the applicability of kDNA-PCR as a prospective routine diagnosis method for American tegumentary leishmaniasis (ATL) in patients from the Instituto de Infectologia Emílio Ribas (IIER), a reference center for infectious diseases in São Paulo - SP, Brazil. The kDNA-PCR method detected Leishmania DNA in 87.5% (112/128) of the clinically suspected ATL patients, while the tradit...

Colombian strain of Trypanosoma cruzi, biodeme Type III (T. cruzi I), has been cloned by micromanipulation at two phases of the acute infection: early (10 days ) and advanced (30 days). Twelve clones were obtained therefrom. Characterization by their biological and biochemical behavior showed an identity among the several clones and their parental strain, albeit with different degrees of virule...

round amastigote form by binary fission in various tissues of the mammalian host. (reviewed in Teixeira [1987]). Research Laboratory American trypanosomiasis infections span an exten-Faculty of Medicine sive geographical area between 42ЊN in the United University of Brasília States to 43ЊS in Argentina. Human Chagas disease is Brasília considered the most significant parasitic disease in Brazil...

The Trypanosoma cruzi acute infections acquired in infancy and childhood seem asymptomatic, but approximately one third of the chronically infected cases show Chagas disease up to three decades or later. Autoimmunity and parasite persistence are competing theories to explain the pathogenesis of Chagas disease. To separate roles played by parasite persistence and autoimmunity in Chagas disease w...

For the last two decades, Dr. Majumder and his group have been involved in research on the enzyme DNA topoisomerases of Leishmania donovani, the causative agent for visceral leishmaniasis or kala-azar. He has made outstanding contribution towards the understanding of the biochemistry of the remarkable kinetoplast DNA (kDNA) network of the parasite and the role of DNA topoisomerases in kDNA meta...

Homologies of minicircle kDNA of 27 Mexican stocks were studied by cross-hybridization with four kDNA probes derived from three reference stocks belonging to groups Trypanosoma cruzi I (SO34 cl4 and Silvio) and T. cruzi II (MN) and one Mexican stock. High homologies were only observed with Silvio (six stocks) and Mexican probes (11 stocks). After 30 min exposure (low homology) additional stocks...

Kinetoplast DNA (kDNA) of trypanosomatid parasites is a network of approximately 5000 catenated DNA minicircles and approximately 25 maxicircles. We developed the following strategy to deduce the topological linkage of the minicircles of the Crithidia fasciculata network. First, we used graph theory to provide precise models of possible network structures. Second, on the basis of these models, ...