Comparative investigations of Latin American trypanosomes with lectins and complement lysis test.

Four-days old epimastigote culture forms of different stocks of Trypanosoma cruzi from Colombia, Costa Rica and Mexico as well of Colombian stocks of T. rangeli were tested with 27 lectins and the complement lysis test. While the stocks of T. cruzi and T. rangeli showed common agglutination reactions with the lectins of Canavalia ensiformis and Pisum sativum, only the stocks of T. cruzi were additionally agglutinated by Ricinus communis-120, Glycine maxima, Helix pomatia, Axinella polypoides, Bandeiraea simplicifolia, Bauhinia purpurea, Wistaria floribunda, Abrus precatorius, Aaptos papillata II, Limax flavus and Arachis hypogaea. On the basis of lectin typing, the strains of T. cruzi belong to the PNA-type. While the epimastigote culture forms of T. cruzi stocks were lysed by normal fresh human, rat, chicken, rabbit and guinea pig serum, the culture forms of T. rangeli were only lysed by chicken serum. Mouse serum had no lytic effect on either trypanosome species. Incubation of T. cruzi with neuraminidase did not alter the lytic effect of the sera. The membrane-associated N-acetylneuraminic acid on T. cruzi does not protect the cell surface against the activation of the alternative complement pathway. After treatment of T. cruzi with neuraminidase and subsequent incubation in culture medium, the PNA-type was restored. The cells reacted again with the lectins of Arachis hypogaea, Limax flavus, Aaptos papillata II but not with Triticum vulgaris.