PCR amplification and sequencing of Trypanosoma cruzi (T. cruzi) spliced-leader intergenic region of the mini-exon gene intergenic region (SL-IR) fragment was performed on intestinal tissue and fecal content DNA extracted from 19 Meccus pallidipennis (M. pallidipennis) specimens collected in the southern region of the State of Mexico. DNA sequence analysis from 49 bp T. cruzi SL-IR showed that all 19 samples corresponded to haplotype TcIa, and all of them were identical to GenBank sequence JQ028863. When extending the analysis to the whole 256 bp amplified sequence of the SL-IR, we found six sequences with a C insertion at position 10, one of which also presented a mutation (T/C) at position 54. One more sequence had an insertion (T) at position 223. Our findings suggest that two dominating TcIa clones are present in M. pallidipennis in the southern region of the State of Mexico. Interestingly, the SL-IR region of the dominating genotype was 100% identical to a circulating clone from Costa Rica present in humans, dogs, Triatoma dimidiata, and Panstrongylus rufotuberculatus. Future regional studies should explore the presence of this haplotype in humans and domestic animals.
Keywords: DTUs; Meccus pallidipennis; Trypanosoma cruzi; haplotypes.