Banca de DEFESA: NATAN PEREIRA DE MEDEIROS ALBERTO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : NATAN PEREIRA DE MEDEIROS ALBERTO
DATE: 07/10/2026
TIME: 09:00
LOCAL: Google Meet
TITLE:

Intestinal colonization and vector competence of Triatoma brasiliensis and Triatoma
pseudomaculata experimentally infected with a Trypanosoma cruzi DTU III Isolate

KEY WORDS:

Susceptibility; triatomines; experimental infection; Chagas disease.

PAGES: 65
BIG AREA: Ciências Biológicas
AREA: Parasitologia
SUMMARY:

Triatoma brasiliensis and Triatoma pseudomaculata are the main vectors of Trypanosoma cruzi in northeastern Brazil, where they are frequently found infected in both natural and anthropogenic environments. Despite their
epidemiological relevance, studies investigating parasite–vector interactions in these species remain scarce. In this context, the aim of this study was to evaluate intestinal colonization, vector competence, and susceptibility to infection of these species following exposure to T. cruzi DTU III. For this purpose, fourth- and fifth-instar nymphs were  fed on mice infected with a T. cruzi DTU III isolate from the state of Rio Grande do Norte, Brazil. After feeding, two approaches were undertaken: (i) dissection of the insects’ gastrointestinal tracts, separation of the intestinal regions, and fresh examination for the quantification and identification of the developmental forms of T. cruzi, in order to assess intestinal colonization; and (ii) examination of feces and intestinal contents over a 90-day period to determine vector competence and susceptibility to infection, followed by PCR analysis of negative samples. Triatoma pseudomaculata showed greater susceptibility to infection, with earlier rectal colonization and a higher likelihood of parasite establishment compared with T. brasiliensis (OR = 4.42; p = 0.01). At 21 days post-infection (dpi), positivity in the hindgut associated with the rectum was 86.6% in T. pseudomaculata and 50% in T. brasiliensis, although parasite loads among positive insects did not differ significantly. In fecal samples, T. pseudomaculata showed progressive elimination of T. cruzi, reaching 83% positivity at 80 dpi, whereas T. brasiliensis reached 58%. Among positive samples, the parasite load excreted by T. pseudomaculata was approximately three times higher than that of T. brasiliensis (p < 0.001). Molecular analysis by PCR confirmed infection in 57.1% (8/14) of T. brasiliensis specimens and in 100% (11/11) of T. pseudomaculata specimens. These results demonstrate that both species are susceptible to infection with T. cruzi DTU III and are capable of supporting parasite development. However, T. pseudomaculata exhibited greater efficiency in intestinal colonization and parasite elimination, whereas T. brasiliensis showed potential vector competence, although this was delayed and limited under the conditions evaluated.

COMMITTEE MEMBERS:
Presidente - 2611909 - CARLOS RAMON DO NASCIMENTO BRITO
Externa ao Programa - 3152261 - ANAMARIA DAL MOLIN - UFRNExterno à Instituição - VAGNER JOSÉ MENDONÇA - UFPI