Trypanosoma cruzi: strain selection by diferent schedules of mouse passage of an initially mixed infection

Abstract

From an initial double infection in mice, established by simultaneous and equivalent inocula of bloodstream forms of strains Y and F of Trypanosoma cruzi, two lines were derived by subinoculations: one (W) passaged every week, the other (M) every month. Through biological and biochemical methods only the Y strain was identified at the end of the 10th and 16th passages of line W and only the F strain at the 2nd and 4th passages of line M. The results illustrate strain selection through laboratory manipulation of initially mixed populations of T. cruzi.

Taxonomy of Trypanosoma cruzi: a commentary on characterization and nomenclature

“…Morever the use of these techniques indicated the possibility of heterogeneity within the T. cruzi strains, with particular strains or isolates being mixtures of at least two populations (Morel et al 1980) and the probability of selective isolation of clones or strains (Deane et al 1984, Macedo & Pena 1998. These and other reasons favoured the view of T. cruzi as a single polytypic species and against a formal subdivsion, as well as illustrating the difficulty of correlating strains with patient morbidity.…”

A comparative parasitologic study on Biomphalaria glabrata snail and C3H/He mice infected with human and murine isolates of Schistosoma mansoni derived from Sumidouro, Rio de Janeiro, Brazil

“…Thus, it has have demonstrated that this parasitic flatworm trematode exhibits a high degree of specificity to the snail host (Frandsen 1979). Furthermore, vertebrate hosts also behave as biological filters to parasites selecting phenotypes and genotypes within natural populations (Deane et al 1984).…”

Biological implications of the phenotypic plasticity in the Schistosoma mansoni - Nectomys squamipes model

“…Vertebrate hosts behave as biological filters to parasites selecting phenotypes and genotypes within natural populations 8 . Hence, parasites may recognize the physiological and biochemical conditions of their hosts that are of selective importance 36 .…”