Integrative metabarcoding reveals Trypanosoma cruzi infection, blood-feeding sources, and gut microbiota in the peridomestic vector Triatoma costalimai

The protozoan parasite Trypanosoma cruzi , the etiological agent of Chagas disease, has a complex cycle involving interactions with triatomine vectors and a variety of vertebrate hosts across sylvatic, peridomestic, and domestic niches. Triatoma costalimai (Hemiptera: Reduviidae) is a native vector species found in the Brazilian Savanna (Cerrado), typically associated with rocky habitats, although it has been increasingly reported in peridomestic settings. This study aimed to investigate T. cruzi infection in T. costalimai specimens collected from peridomestic environments in rural areas of the Brazilian Savanna. Metabarcoding and high-throughput DNA sequencing of intestinal samples were employed. In addition, we characterized vertebrate blood meal sources and gut microbiota from the same individuals. Six of thirteen specimens analyzed were positive for T. cruzi . Blood meal analysis identified DNA from domestic vertebrate hosts, including chickens, cats, and cattle, while human DNA was detected in two specimens. Furthermore, the phylum Actinobacteriota was the most abundant bacterial phylum in the gut microbiome. Together, these findings show the co-occurrence of T. cruzi , domestic vertebrate host signals, and a diverse bacterial microbiota in the analyzed peridomestic T. costalimai specimens. In this context, integrative approaches that combine parasite detection, blood meal source identification, and gut microbiota characterization provide a more comprehensive framework for understanding how these insects contribute to the spread of Chagas disease and highlight the importance of monitoring them in areas near human habitation. From an epidemiological perspective, our results support the importance of continued surveillance of T. costalimai in peridomestic environments close to human dwellings, while further studies with larger and more representative samples are needed to determine its role in local T. cruzi transmission dynamics. Not applicable.