Trypanosoma cruzi: quantification and analysis of the infectivity of cloned stocks.

The infection of bovine embryo skin and muscle cells by trypomastigotes of four Trypanosoma cruzi clones (CA-I/71, /72, Miranda/76, /80) was quantified. Stable and reproducible intra-isolate differences were observed; an almost 70-fold difference in infectivity occurred between clones. The CA-I/71 clone was not susceptible to N-acetyl-D-glucosamine at a concentration that inhibits the infection of vertebrate cells by Ernestina and Y-strain parasites. Eight other monosaccharides that are common constituents of vertebrate cell surface glycoproteins also failed to inhibit the infection of vertebrate cells by the CA-I/71 clone.