TcI/TcII co-infection can enhance Trypanosoma cruzi growth in Rhodnius prolixus

Abstract

BackgroundRhodnius prolixus is an obligate haematophagous insect and one of the most important vectors of Trypanosoma cruzi, the causative agent of Chagas disease in the Americas. T. cruzi is a highly variable parasite which is not transmitted in the same efficiency by the different triatomine vectors. Because different T. cruzi genotypes are aetiopathologically divergent, further elucidation of the transmission abilities of different Chagas disease vectors is extremely important.FindingsIn the present study, the growth behaviour of two T. cruzi isolates, MDID/BR/1993/C45 (TcI) and TBRA/BR/1999/JCA3 (TcII), sharing the same microhabitat (intestinal tract) in single and mixed infections, was examined. The distribution patterns and parasite population densities were evaluated at 7, 14 and 21 days after feeding (daf) by quantification of parasites using Neubauer haemocytometric measurements and mini-exon PCR to identify TcI and TcII subpopulations. Parasitic colonization in the small intestine was more successful in the mixed infection model than the single infection models at 21 daf. In the rectal lumen and wall, the growth behaviour of the mixed infection was similar to that of the TcI group, although the total parasite number was lower. In the TcII group, no metacyclic trypomastigote forms were found. PCR analysis of the contents of each dissected region showed different genotype fractions in the mixed infection model, in which TcI seemed to be the predominant isolate.ConclusionThe different growth behaviour of the TcI and TcII isolates in single and mixed infection models demonstrated that possibly an intraspecific factor modulates parasitic development in the intestine of R. prolixus.

Rhodnius prolixus Life History Outcomes Differ when Infected with Different Trypanosoma cruzi I Strains

“…This parasite concentration is similar to that used in several other published studies of T. cruzi infection in triatomines, 9,44,46,50,[54][55][56][57][58][59] and blood meals taken by triatomines at this parasite concentration lead to infective doses that fall within the range of peak parasitemias observed in mice and guinea pigs experimentally infected with T. cruzi. 25,27,[60][61][62][63] Insect infection: insect preparation and feeding.…”

Interactions BetweenTrypanosoma cruzithe Chagas Disease Parasite and Naturally Infected WildMepraiaVectors of Chile

“…However, these interactions can be recent, as seems to occur as shown here with M. gajardoi and T. cruzi DTUs TcVI, which diverged very recently. Finally, since not all triatomine species develop different T. cruzi DTUs, this suggests that triatomines of a different genus rather than species of the same genus are differently adapted to each T. cruzi DTU (Mejía-Jaramillo et al 2009, Araújo et al 2014. The different microbiota present in triatomine guts of different genera seem to contribute to this interesting and epidemiologically relevant parasite-invertebrate interaction (Da Mota et al 2012).…”

“…The term ''discrete typing unit'' (Tibayrenc 1998) was proposed to describe sets of stocks that are genetically more similar to each other than to any other stock and are identifiable by common molecular markers sometimes referred to as ''tags.'' Experimental infections have demonstrated in pioneer studies that not all T. cruzi DTUs succeed in growing and completing their development in all triatomine species (Garcia et al 1982, Azambuja et al 1989, Mello et al 1996, Urrea et al 2005, Araújo et al 2007, Mejía-Jaramillo et al 2009,Vallejo et al 2009, Araújo et al 2014.…”

Sympatry influence in the interaction of Trypanosoma cruzi with triatomine

“…In studies with another species of the same genus, R. prolixus, the findings indicated that some T. cruzi strains did not develop within its intestinal tract to produce metacyclic trypomastigotes, but it was able to maintain parasites in its rectal lumen 39,48,49 . In many cases, under our experimental conditions, infection of the insect was only proven by PCR, demonstrating the greater capacity of detection of this technique when compared to the others.…”