Growth characteristics in axenic and cell cultures, protein profiles, and zymodeme typing of three Trypanosoma cruzi isolates from Louisiana mammals.

Rates of trypomastigote adherence, interiorization, amastigote division in, and trypomastigote release from Vero cells were measured for Trypanosoma cruzi isolates from a dog (Tc-D), opossum (Tc-O), and an armadillo (Tc-A) from Louisiana. Because the Tc-O and Tc-A (wild isolates) trypomastigotes became interiorized rapidly, the media were quickly depleted of trypomastigotes thus reducing the numbers available to adhere to cells. In contrast, the Tc-D trypomastigote interiorization rate was slower. Intracellular amastigote division rate was slower for the Tc-D than the wild isolates. The Tc-D trypomastigotes were released from cells approximately 2 days later than wild isolate trypomastigotes, but twice the number were released. Growth rate for Tc-D epimastigotes in liver infusion tryptose media was faster than that of wild isolates. The doubling times for Tc-D, Tc-O, and Tc-A were 48.0, 69.0, and 67.4 hr, respectively. Soluble parasite extract was produced from epimastigotes of each isolate by freeze/thawing, sonication, and high-speed centrifugation. Proteins were separated on an SDS-PAGE slab gel and stained with Coomassie blue. Although similar bands were present in each preparation, the general pattern of staining was similar only between the Tc-O and Tc-A preparations, which showed some differences from the Tc-D preparation. Each isolate was zymodeme typed using 5 enzymes in lysates produced from epimastigotes of each isolate. Enzymes were separated electrophoretically and stained. Wild isolates showed similar patterns as zymodeme 1 reference stock, whereas the Tc-D isolate produced a pattern that did not resemble any of the reference stocks examined.