DOI: 10.5061/dryad.kh1893294
title: Trypanosoma cruzi in Mexican Neotropical vectors and mammals: Wildlife, livestock, pets, and human population

description: The aim of the present study has been to provide primary evidence of
 Trypanosoma cruzi landscape genetics in the Mexican Neotropics. T. cruzi
 and 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.  Although 98% of the
 infected sample set (N=2963) contained single or mixed infections of DTUI
 (TcI, 96.2%) and TcVI (22.6%), TcIV and TcII were identified. The
 sensitivity of individual markers varied and was dependent on the 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.
 Available gene fragments to identify or genotype T. cruzi are not
 universally sensitive for all landscape parasite populations, highlighting
 important T. cruzi heterogeneity among mammal reservoir taxa and
 triatomine species.
description: Vectors were collected either
 by inhabitants in and around houses or technical personnel in landscapes
 which included domestic fragment (housing community) or using various
 collection methods (light traps, animal bait) in ecotone (agricultural and
 livestock grazing areas) and sylvatic (conserved) habitats. Specimens
 of Triatoma dimidiata haplogroup 1 (Hg1), <em>T.
 dimidiata</em> haplogroup 2 (Hg2), <em>T.
 dimidiata</em> haplogroup 3 (Hg3), <em>Triatoma
 pallidipennis</em>, <em>Triatoma phyllosoma</em>,
 and <em>Panstrongylus rufotuberculatus</em> were taxonomically
 identified and preserved in 70% EtOH, as previously
 described. Wildlife specimens were collected as previously
 described across landscape habitats, taxonomically identified, euthanized,
 and tissues (exclusively from heart tissue are reported herein) were
 preserved immediately in 95% molecular grade EtOH or DNazol (Invitrogen,
 San Diego, California, USA). Blood samples from livestock (5ml), pets
 (3ml), and one protected bat species (<em>Myotis velifer</em>;
 0.3 ml) were drawn in guanidine buffer. Following informed consent,
 including permission for subsequent use of remaining aliquots, a blood
 sample (5ml) was drawn in EDTA for standard serology (2-5 tests only for
 humans), and an additional sample (5ml) preserved in guanidine buffer for
 molecular <em>T. cruzi</em> detection. The conserved region of
 the kDNA (S34/S67primers) was chosen as the primary multiple copy
 mitochondrial fragment for <em>T. cruzi</em> infection in all
 taxa as previously described. All samples were analyzed herein using the
 kDNA and the conserved repeat of the spliced leader mini-exon (ME), and
 all samples amplified using either marker, 100% of kDNA negative vector,
 bat and human samples, and a random selection of 25% of all other kDNA
 negative samples were also amplified using primers for the small subunit
 rDNA 18S gene using the primers SSU561F/SSU561R (N=2103). A random
 selection of 70% of kDNA-positive samples and all equine and livestock
 samples were also analyzed using the 24Sα gene using the D71/ D72
 primers.  All amplicons of expected band size of the kDNA
 (120bp), those between 300 and 350 bp of the ME, all amplification
 products between 520-720 bp of the 18S, and all 24S amplicons within the
 range of 110 to 125 bp were sequenced.
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