Trypanosoma cruzi isolates from Mexican and Guatemalan acute and chronic chagasic cardiopathy patients belong to Trypanosoma cruzi I

Abstract

Trypanosoma cruzi is classified into two major groups named T. cruzi I and T. cruzi II. In the present work we analyzed 16 stocks isolated from human cases and four isolated from triatomines from diverse geographical origins (Mexico and Guatemala). From human cases four were acute cases, six indeterminates, and six from chronic chagasic cardiophatic patients with diagnosis of dilated cardiomyopathy established based on the left-ventricular end systolic dimension and cardiothoracic ratio on chest X-radiography and impaired contracting ventricle and different degree conduction/rhythm aberrations. DNA samples were analyzed based on mini-exon (ME) polymorphism, using a pool of three oligonucleotide for the amplification of specific intergenic region of T. cruzi ME gene.All the Mexican and Guatemalan isolates regardless their host or vector origin generated a 350 bp amplification product. In conclusion T. cruzi I is dominant in Mexico and Guatemala even in acute and chronic chagasic cardiopathy patients. To our knowledge, this is the first study describing predominance of T. cruzi I in human infection for North and Central America. Key words Trypanosoma cruzi -mini-exon -Mexico -lineage I -GuatemalaTrypanosoma cruzi is classified into T. cruzi I and T. cruzi II, this denomination aroused from a consensus reached by specialists based on different markers (Satellite Meeting 1999). T. cruzi I is mainly observed in wild mammals and more adapted to marsupials and sylvan triatomines, it is only occasionally isolated from humans, whereas T. cruzi II is apparently more associated with primates and it is usually found in human infections. Until now all parasites that have been isolated from seropositive individuals in Brazil belong to T. cruzi II (Fernandes et al. 1998. Recently a published report paper show a predominance of lineage I in 56 Mexican T. cruzi stocks isolated from vectors, humans, and sylvatic mammals using RAPDs, but the clinical status of human cases was not identified (Bosseno et al. 2002). In South-America also was found in 23 isolates from acute chagasic patients using ribosomal and miniexon (ME) marker that 74% of them belonged to T. cruzi I (Anez et al 2004). It is known that the ME gene is presented in the nuclear genome of all Kinetoplastida in nearly 200 copies in tandemly-repeated sequences. This gene consist of three regions: exon, intron, and intergenic region. The exon is highly conserved, the intron is moder- ately conserved and the intergenic region or non-transcribed spacer is particular dissimilar. This feature has allowed the classification of T. cruzi in two main groups (Devera et al. 2003, Macedo et al 2004.In the present work we analyzed 16 stocks isolated from human cases and four isolated from triatomines all from with diverse geographic origins (Mexico and Guatemala). Seven came from Guatemala and 13 from Mexico.Six were isolated from chronic chagasic cardiopathyc (CCC) patients who were evaluated at Instituto Nacional Cardiología "I. Chávez" in Mexico. All of them have been diagnosed ...

Presence of Virginia opossum (Didelphis virginiana) and Pic (Triatoma dimidiata) infected with Trypanosoma cruzi in urban areas: preliminary evaluation in the city of Campeche, Mexico

“…The predominance of T. cruzi Lineage I in Mexico is not limited to just marsupials; it has also being found in humans and vectors (Ruíz-Sánchez et al 2005, Gómez-Hernández et al 2011. Our findings contrast with those from South American countries were T. cruzi lineage II is the main genotype associated with human infections (domestic cycle) (Bosseno et al 2002).…”

Microsatellite and Mini-Exon Analysis of Mexican Human DTU ITrypanosoma cruziStrains and Their Susceptibility to Nifurtimox and Benznidazole

“…In Mexico, most T. cruzi strains have been genetically determined to belong to TcI (Bosseno et al 2002, Leó n-Pérez et al 2007, Gó mez-Hernández et al 2011 and TcII-TcVI strains have been reported only in a recent serological study, in wild mammals and the feces of vectors (Ló pez-Olmos et al 1998, Bosseno et al 2009, Risso et al 2011. In this work, we confirmed that the Mexican T. cruzi strains isolated from humans belonged to TcI, as reported in Guatemala, Colombia, and Venezuela (Añ ez et al 2004, Ruíz-Sánchez et al 2005, Falla et al 2009). In the present work, 2 other strains from wild mammals belonging to TcIITcVI groups were also identified, but their association with any specific DTU remains to be determined.…”

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

“…The following eight T. cruzi strains were studied: three strains isolated from Triatoma pallidipennis (CGH2, CGH4, and CGH6 strains), two from Triatoma longipennis (CGH1 and CGH3 strains), one from Triatoma picturata (KR1 strain), one by xenodiagnosis from a patient in the acute phase of disease (NINOA strain) 21 , and one isolated from a patient with the chronic cardiac form (INC-5 strain) 22 (Table 1).…”