Isoenzyme characterization of Trypanosoma cruzi from congenital cases of Chagas' disease.

The isoenzyme profiles of a group of five Trypanosoma cruzi stocks obtained from congenital cases and of a second group of seven stocks obtained from chagasic mothers who did not transmit their infection congenitally were studied by electrophoresis of nine enzymes. All the mothers became infected in Bahia State (Brazil). With the exception of a triple 'heterozygous' GPI pattern, all T. cruzi stocks were identified as zymodeme 2 (Z2). The heterozygous pattern has not been recorded previously in Bahia. This study shows that enzymically similar T. cruzi stocks can show different behaviour with respect to transplacental transmission, and also with respect to clinicopathological presentation and therapeutic response of the congenital cases.