Genotypic Trypanosoma cruzi distribution and parasite load differ ecotypically and according to parasite genotypes in k from endemic and outbreak areas in Northeastern Brazil

Author(s):Show less -

Valenca-Barbosa, Carolina ^{[1, 2]} ; Finamore-Araujo, Paula ^[3] ; Moreira, Otacilio C. ^[3] ; Vergara-Meza, Jose Gabriel ^[4] ; Niz Alvarez, Marcus Vinicius ^[5] ; Nascimento, Juliana R. ^[6] ; Borges-Veloso, Andre ^{[1, 2]} ; Viana, Maria Carolina ^[1] ; Lilioso, Mauricio ^[1] ; Miguel, Danilo Ciccone ^[1] ; Gadelha, Fernanda Ramos ^[1] ; Geraldes Teixeira, Marta Maria ^[4] ; Almeida, Carlos Eduardo ^{[7, 1]}

Affiliation

^[1] Univ Estadual Campinas, Inst Biol, UNICAMP, Sao Paulo - Brazil

^[2] Fundacao Oswaldo Cruz Fiocruz, Inst Rene Rachou, Grp Triatomineos, Belo Horizonte, MG - Brazil

^[3] Inst Oswaldo Cruz Fiocruz, Lab Biol Mol & Doencas Endem, Rio De Janeiro - Brazil

^[4] Univ Sao Paulo, Inst Ciencias Biomed, Sao Paulo - Brazil

^[5] Univ Estadual Paulista, Inst Biotecnol Botucatu, Botucatu, SP - Brazil

^[6] Univ Fed Fluminense, Inst Quim, Niteroi, RJ - Brazil

^[7] Univ Fed Bahia, Inst Biol, Salvador, BA - Brazil

• Document type: Journal article
• Source: Acta Tropica; v. 222, OCT 2021.
• Web of Science Citations: 0

Abstract

This study aimed to identify the Trypanosoma cruzi genotypes and their relationship with parasitic load in distinct geographic and ecotypic populations of Triatoma brasiliensis in two sites, including one where a Chagas disease (ChD) outbreak occurred in Rio Grande do Norte state, Brazil. Triatomine captures were performed in peridomestic and sylvatic ecotopes in two municipalities: Marcelino Vieira - affected by the outbreak; and Currais Novos - where high pressure of peridomestic triatomine infestation after insecticide spraying have been reported. The kDNA-PCR was used to select 124 T. cruzi positive triatomine samples, of which 117 were successfully genotyped by fluorescent fragment length barcoding (FFLB). Moreover, the T. cruzi load quantification was performed using a multiplex TaqMan qPCR. Our findings showed a clear ecotypic segregation between TcI and TcII harboured by T. brasiliensis (p<0.001). Although no genotypes were ecotypically exclusive, TcI was predominant in peridomestic ecotopes (86%). In general, T. brasiliensis from Rio Grande do Norte had a higher T. cruzi load varying from 3.94 to 7.66 x 106 T. cruzi per insect. Additionally, TcII (median value=299,504 T. cruzi/intestine unit equivalents) had more than twice (p=0.1) the parasite load of TcI (median value=149,077 T. cruzi/intestine unit equivalents), which can be attributed to a more ancient co-evolution with T. brasiliensis. The higher prevalence of TcII in the sylvatic T. brasiliensis (70%) could be associated with a more diversified source of bloodmeals for wild insect populations. Either TcI or TcII may have been responsible for the ChD outbreak that occurred in the city of Marcelino Vieira. On the other hand, a smaller portion of T. brasiliensis was infected by TcIII (3%) in the peridomicile, in addition to T. rangeli genotype A (1%), often found in mixed infections. Our results highlight the need of understanding the patterns of T. cruzi genotype ` s development and circulation in insect vectors and reservoirs as a mode of tracking situations of epidemiologic importance, as the ChD outbreak recently recorded for Northeastern Brazil. (AU)

• FAPESP's process: 16/08176-9 - An integrative approach to morphological and molecular diversity of Triatoma brasiliensis, the main Chagas Disease vector in the Brazilian semiarid: elucidating links along the epidemiological chain
• Grantee: Carlos Eduardo de Almeida
• Support Opportunities: Research Grants - Young Investigators Grants