Trypanosoma cruzi DTU TcII presents higher blood parasitism than DTU TcI in an experimental model of mixed infection.

Trypanosoma cruzi (Tc), the causative agent of Chagas disease, affects millions of people worldwide. One of the major characteristics of T. cruzi is related to its heterogeneity due to the variability of its biological properties, parasite growth rates, infectivity, tissue tropism, morbidity and virulence among different isolates observed during experimental or human infection.

High similarity of Trypanosoma cruzi kDNA genetic profiles detected by LSSP-PCR within family groups in an endemic area of Chagas disease in Brazil.

Introduction: Determining the genetic similarities among Trypanosoma cruzi populations isolated from different hosts and vectors is very important to clarify the epidemiology of Chagas disease.

Methods: An epidemiological study was conducted in a Brazilian endemic area for Chagas disease, including 76 chronic chagasic individuals (96.1% with an indeterminate form; 46.

Effects of cholinergic stimulation with pyridostigmine bromide on chronic chagasic cardiomyopathic mice.

The aim of the present study was to assess the effects of an anticholinesterase agent, pyridostigmine bromide (Pyrido), on experimental chronic Chagas heart disease in mice. To this end, male C57BL/6J mice noninfected (control:Con) or chronically infected (5 months) with Trypanosoma cruzi (chagasic:Chg) were treated or not (NT) with Pyrido for one month. At the end of this period, electrocardiogram (ECG); cardiac autonomic function; heart histopathology; serum cytokines; and the presence of blood and tissue parasites by means of immunohistochemistry and PCR were assessed.

A DTU-dependent blood parasitism and a DTU-independent tissue parasitism during mixed infection of Trypanosoma cruzi in immunosuppressed mice.

Trypanosoma cruzi (Tc) diversity is determined by different biological, genetic, and biochemical markers and has been grouped into six discrete typing units (DTUs) or taxonomic groups (TcI-TcVI). This variability, coupled with natural reinfection or the hosts' immunosuppression, may play an important role in the pathogenesis of Chagas disease. Therefore, we evaluated the blood and tissue parasitism and genetic profile of mice coinfected with the TcII (JG) strain and TcI AQ1-7 (AQ) or MUTUM (MT) strains during the acute and chronic phases of the disease and during immunosuppression.

Non-biting flying insects as carriers of pathogenic bacteria in a Brazilian hospital.

Introduction: Insects have been described as mechanical vectors of nosocomial infections.

Methods: Non-biting flying insects were collected inside a pediatric ward and neonatal-intensive care unit (ICU) of a Brazilian tertiary hospital.

Results: Most (86.

Trypanosoma cruzi experimental congenital transmission associated with TcV and TcI subpatent maternal parasitemia.

The congenital transmission of Chagas disease is associated with an increase in parasitemia during pregnancy, maternal and fetal immunity, and populations of Trypanosoma cruzi. In this study, the biological behavior of TcI and TcV (isolated from a human congenital case) strains and their potential for experimental congenital transmission were evaluated in female BALB/C mice. Parasitemia was estimated by fresh blood examination, semiquantitative microhematocrit, and hemoculture, while congenital transmission was evaluated by culture in the liver infusion tryptose medium and by polymerase chain reaction (PCR) of the pups' tissues on postnatal day 7 and of the pups' blood sample at 30 days after birth.

Molecular characterization of Trypanosoma cruzi Mexican strains and their behavior in the mouse experimental model.

Introduction: For a long time, the importance of Chagas disease in Mexico, where many regarded it as an exotic malady, was questioned. Considering the great genetic diversity among isolates of Trypanosoma cruzi, the importance of this biological characterization, and the paucity of information on the clinical and biological aspects of Chagas disease in Mexico, this study aimed to identify the molecular and biological characterization of Trypanosoma cruzi isolates from different endemic areas of this country, especially of the State of Jalisco.

Methods: Eight Mexican Trypanosoma cruzi strains were biologically and genetically characterized (PCR specific for Trypanosoma cruzi, multiplex-PCR, amplification of space no transcript of the genes of the mini-exon, amplification of polymorphic regions of the mini-exon, classification by amplification of intergenic regions of the spliced leader genes, RAPD (random amplified polymorphic DNA).