Trypanosoma cruzi in Mexican Neotropical vectors and mammals: wildlife, livestock, pets, and human population

Abstract

Objective. To provide primary evidence of Trypanosoma cruzi landscape genetics in the Mexican Neotropics. Materials and methods. Trypanosoma cruzi and discrete typing units (DTU) prevalence were analyzed in landscape communities of vectors, wildlife, livestock, pets, and sympatric human populations using endpoint PCR and sequencing of all relevant amplicons from mitochondrial (kDNA) and nuclear (ME, 18S, 24Sα) gene markers. Results. Although 98% of the infected sample-set (N=2 963) contained single or mixed infections of DTUI (TcI, 96.2%) and TcVI (22.6%), TcIV and TcII were also identified. Sensitivity of individual markers varied and was dependent on host taxon; kDNA, ME and 18S combined identified 95% of infections. ME genotyped 90% of vector infections, but 60% of mammals (36% wildlife), while neither 18S nor 24Sα typed more than 20% of mammal infections. Conclusion. Available gene fragments to identify or genotype T. cruzi are not universally sensitive for all landscape parasite populations, highlighting important T. cruzi heteroge- neity among mammal reservoir taxa and triatomine species.