Trypanosoma cruzi isolates from Argentina and Chile grouped with the aid of DNA probes.

Fifty-two isolates and several clones from Trypanosoma cruzi, the agent of Chagas' disease, were analyzed using cloned minicircles or total kinetoplast DNA as probes. Isolates were obtained from triatomines, guinea pigs and infected humans in the Central and Northern regions of Argentina and the North of Chile. 35% of all the randomly selected isolates could be identified with one cloned minicircle probe. This widely distributed T. cruzi group was detected on both sides of the Andes mountain range (Argentina and Chile) in Triatoma infestans as well as in human infections. Most of the other isolates could be grouped with four kinetoplast DNAs as probes, but their geographical distribution seems to be restricted as compared with the one mentioned above. These results confirm the heterogeneity of T. cruzi subspecies in nature and the usefulness of DNA probes to group them.