Chapter category: Infectious Disease
Genetic Diversity of Trypanosoma cruzi and the Epidemiology of Chagas Disease
Molecular Mechanisms of Pathogenesis in Chagas Disease
Edited by: JohnM. KellyISBN: 0-306-47849-8
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Chapter authors:
Michael A Miles, Matthew Yeo and Michael Gaunt
The complex epidemiology of Chagas disease is not fully understood. It has
been suggested that distinct genotypes of Trypanosoma cruzi may cause the severe
(megasyndromes)
and benign forms of chronic Chagas disease, which appear to differ in geographical
distribution. Multi-locus enzyme electrophoresis (MLEE) and analyses of DNA
polymorphisms with several targets have demonstrated that T. cruzi has
a remarkable degree of genetic diversity. Both isoenzyme and DNA analyses define
two major subdivisions within the species, T. cruzi I and T.
cruzi II, with marked heterogeneity and five subdivisions within T. cruzi
II (II a-e). Population genetic analyses have indicated that T. cruzi
is predominantly clonal, although the isolates studied have mainly been sporadically
collected over vast geographical distances. However, T. cruzi IId and
IIe display putatively hybrid phenotypes in the form of multiple heterozygous
isoenzyme phenotypes. Phylogenetics analyses have confirmed the hybrid nature
of T. cruzi IId and IIe and indicate that genetic exchange has contributed
to the evolution of genetic diversity in T. cruzi. The T. cruzi
strain selected for the genome sequencing project is a hybrid (IIe) strain.
We have proved experimentally that T. cruzi I has an active capacity
for genetic exchange using parental isolates taken from a single locality where
parents and hybrids were sympatric. Experimentally derived hybrid clones displayed
a combination of parental phenotypes and genotypes, indicating that T. cruzi
may evolve via hybridisation, aneuploidy and genome erosion. We propose tentative
associations for T. cruzi I, with the maruspial Didelphis (common
opossum), the triatomine genus Rhodnius and the palm tree ecotope, and
for T. cruzi II with edentates (armadillos), rodents, the triatomine
genus Triatoma and the terrestrial ecotope. We conclude that there must
be a link between T. cruzi genotype and outcome of infection but the
nature of the link in terms of disease pathogenesis remains to be defined.
Additional chapters from this book:
How Does Trypanosoma cruzi Survive the Toxic Effects of Reactive Oxygen Species?
Shane R. Wilkinson and John M. Kelly
Biological molecules are subject to attack by reactive oxygen species (ROS) leading to membrane disruption, inactivation of essential enzymes, mutagenesis and damage to DNA repair machinery. I...
Activation of BradykininReceptors by Trypanosoma cruzi: A Role for Cruzipain in Microvascular Pathology
Julio Scharfstein
During its life cycle in the mammalian host, Trypanosoma cruzi productively exploits the enzymatic diversity of its own proteases to generate activation signals for a broad range...
Trypanosoma cruzi trans-Sialidase: A Cytokine Mimetic (Parasitokine)
Wenda Gao and Miercio A. Pereira
Cytokines are small soluble proteins with high potency in orchestrating host immune responses during stress, injury, tumorgenesis, and infection. Studies in animal models and human...
Impact of Polyclonal Lymphocyte Responses on Parasite Evasion and Persistence
Paola Minoprio
In the field of immunoparasitology it is generally accepted that the survival and degree of pathogenicity of parasites is inextricably linked to their ability to escape and resi...
Ca2+ Signaling in the Invasion of Mammalian Cells by Trypanosoma cruzi
Silvia N.J. Moreno and Roberto Docampo
In order to replicate in the mammalian host, Trypanosoma cruzi must invade host cells. Changes in the intracellular Ca2+ concentration ([Ca2+]i
The Trypanosoma cruzi Mucin Coat: Structure, Regulation of the Expression and Relevance in the Host-Parasite Relationship
Javier M. Di Noia, Ivan D'Orso and Alberto Carlos C. Frasch
The cell surface of Trypanosoma cruzi, the agent of the Chagas disease, is covered by a family of highly O-glycosylated mucin-like glycoproteins. This coat protects the para...
Distinct Mechanisms Operate to Control Stagespecific and Cellcycle Dependent Gene Expression in Trypanosoma cruzi
Maria Carolina Q. Barbosa Elias, Rafael Marques Porto, Marcella Faria and Sergio Schenkman
Proliferation and differentiation are key events for the establishment of infection by Trypanosoma cruzi and consequently, for the pathogenesis of Chagas' disease. Therefore...
Genetic Diversity of Trypanosoma cruzi and the Epidemiology of Chagas Disease
Michael A Miles, Matthew Yeo and Michael Gaunt
The complex epidemiology of Chagas disease is not fully understood. It has been suggested that distinct genotypes of Trypanosoma cruzi may cause the severe (megasyndromes) and b...
The Role of Nitric Oxide in the Pathogenesis of Trypanosoma cruzi Infection
Gislâine A. Martins, Mauro M. Teixeira and João S. Silva
This Chapter summarizes the roles of nitric oxide (NO) in mediating and controlling the effector immune response against Trypanosoma cruzi and in the pathology resulting from the infect...
