Dynamics of food sources, ecotypic distributtion and Trypanosoma cruzi (Chagas, 1909) infection in triatomines from the northeast of Brazil

Author(s)

Maurício Lilioso de Lucena Filho

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2022-10-03

Examining board members

Carlos Eduardo Almeida; João Aristeu Rosa; Silmara Marques Allegretti; Kaio Cesar Chaboli Alevi; Elaine Folly Ramos

• Advisor: Carlos Eduardo Almeida

Abstract

Chagas disease is a parasitic disease whose etiological agent is Trypanosoma cruzi, this parasite is classically transmitted by hemipterans of the Triatominae subfamily. Members of the Triatoma brasiliensis species complex are important vectors of this parasite in Northeast Brazil. Chagas disease develops in different regional settings and has different ecoepidemiological patterns. Thus, with the objective of assisting in the ecoepidemiological knowledge of the vectors of Chagas disease in Northeast Brazil, the food sources of Triatoma brasiliensis brasiliensis and Triatoma petrocchiae were characterized. In this study, sequencing of the cytochrome B mitochondrial gene (cytb) was applied to DNA isolated from the abdominal contents of triatomines from peridomestic and wild environments captured in the states of Paraíba and Rio Grande do Norte, using universal vertebrate primers. Then, the identification of the blood meal was performed via BLAST. The identification of the food source was combined with the ecotypic distribution of the insects. Also, with the same DNA used for the characterization of food sources, analyzes of natural infection in T. b. brasiliensis by T. cruzi. Occupation hypotheses were analyzed with populations of T. b. brasiliensis, so it was investigated whether the occupation of ecotopes by T. b. brasiliensis is motivated by ecotope structure or association with key hosts. In this study, cavid rodents were identified as the main food sources of T. b. brasiliensis in natural and anthropized environments. The association of these organisms (cavids + T. b. brasiliensis) was commonly accompanied by large populations of triatomines infected with T. cruzi in artificial ecotopes, both of mineral and plant origin. Therefore, it was suggested that cavids, especially Galea spixii, accompanied by Kerodon rupestris, drive T. b. brasiliensis, in addition to most likely these rodents are in synanthropy process, as they were identified as a food source for T. b. brasiliensis both in wild and domestic environments. Other animals, such as domestic cats, may play an important role in the transmission cycles of T. cruzi, as they are an important food source for triatomines in all analyzed ecotopes. This study also revealed that in wild environments T. petrocchiae cohabiting with T. b. brasiliensis prefers to feed on reptiles, indicating that there is possibly no competition for trophic resources between T. petrocchiae and T. b. brasiliensis, which showed a clear preference for cavids (AU)

• FAPESP's process: 17/21359-8 - Integrated molecular approaches to elucidate the ecological associations of Triatoma brasiliensis: food sources, microbiota and diversity of Trypanosoma cruzi
• Grantee: Maurício Lilioso de Lucena Filho
• Support Opportunities: Scholarships in Brazil - Doctorate