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.
Highlights
MethodsParasites The T. cruzi isolate MDID/BR/1993/C45 (C45/TcI) was obtained from the naturally infected marsupial host Philander frenatus from Teresópolis, Rio de Janeiro, south-east Brazil [18]
Rhodnius 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
The present study characterized the colonization profiles of two T. cruzi isolates (TcI, MDID/BR/1993/C45 and T. cruzi II (TcII), TBRA/BR/1999/JCA3) in different regions of the R. prolixus intestinal tract. This analysis showed that the C45/TcI isolate was better adapted to R. prolixus than JCA3/TcII, as indicated by the greater parasitic colonization
Summary
Parasites The T. cruzi isolate MDID/BR/1993/C45 (C45/TcI) was obtained from the naturally infected marsupial host Philander frenatus from Teresópolis, Rio de Janeiro, south-east Brazil [18]. The second isolate, TBRA/BR/ 1999/JCA3 (JCA3/TcII), was recovered from naturally infected Triatoma brasiliensis from the João Costa municipality of Piauí, north-east Brazil. For T. cruzi infections, three groups of insects were artificially fed through latex membranes using parasites (C45/TcI, JCA3/TcII and 50% C45/TcI + 50% JCA3/TcII) maintained in LIT culture medium near the end of their log phase, washed with phosphate buffered saline (pH 7.2) and diluted in citrated, heat-inactivated rabbit blood [23,24,25]. About 20 days later, the insects moulted to fifth instar nymphs (L5) and were fed 14 days afterward with parasite-free rabbit blood. Because some insects died or were not fully engorged, a final total of 90 L5 nymphs were used for the present analysis
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
