Effect of vector on infectivity of Trypanosoma cruzi.
A comparative study was carried out on the interaction between Triatoma infestans and bloodstream forms (BSF) of Trypanosoma cruzi isolates RA and UP, both lethal for mouse, and CA-I nonlethal for this host. Parasite duplication was readily detected in triatomes fed with CA-I, metacyclic (Mtc) differentiation reaching a maximum at an optimum ingestion level of 250 BSF/insect. Progress and differentiation proved much lower for RA, but reached intermediate values for the UP isolate. Assays for infectivity for each isolate after bug passage revealed a drop for the RA and UP, whereas for CA-I an increase was observed indicating that virulence of BSF and Mtc differs. Our results suggest that parasite selection by insect passage modulates infectivity of a given parasite population; however, virulence was independent of the absolute number of Mtc in the insect's feces.
Lammel
E L
EL
Müller
L A
LA
Isola
E L
EL
González Cappa
S M
SM
D000818:Animals; D005243:Feces / Q000469:parasitology; D006790:Host-Parasite Interactions; D007303:Insect Vectors / Q000469:parasitology*; D051379:Mice / Q000469:parasitology; D012641:Selection, Genetic; D014224:Triatoma / Q000469:parasitology*; D014225:Triatominae / Q000469:parasitology*; D014349:Trypanosoma cruzi / Q000254:growth & development / Q000472:pathogenicity*; D014774:Virulence