SHORT COMMUNICATION Trypanosoma cruzi: ubiquity expression of surface cruzipain molecules in TCI and TCII field isolates Patrícia Fampa & André L. S. Santos & Marcel I. Ramirez Received: 17 November 2009 / Accepted: 20 April 2010 / Published online: 30 May 2010 # Springer-Verlag 2010 Abstract Trypanosoma cruzi presents considerable genetic and protein profile polymorphism among different parasite populations. In a previous work, our group indicated cysteine and metalloprotease activities as good markers for separating T. cruzi I (TCI) from T. cruzi II (TCII) isolates, with higher heterogeneity among TCII isolates. Here, we have investi- gated the expression level of surface cruzipain in 16 field isolates belonging to the genotype TCI (n =8) and TCII (n = 8) of T. cruzi. By means of flow cytometry analyses, using an anti-cruzipain polyclonal antibody, we observed a highly heterogeneous pattern of surface cruzipain molecules in these isolates, independently of their genotypes, cell measurements (size and granularity), original hosts, or biomes. However, fluorescence labeling tended to be stronger in TCI than in TCII population. Interestingly, isolates that expressed higher levels of surface cruzipain also yielded elevated levels of metacyclogenesis in vitro. Introduction Trypanosoma cruzi is the etiological agent of Chagas’ disease. It is a heteroxenous parasite, which transmission involves invertebrate (triatomine vector insects) and mammals as alternating hosts. Parasite life cycle is characterized by different morphological stages. Intra- cellular replicative amastigotes and nonreplicative blood- stream trypomastigotes are found in the mammalian hosts, while replicative epimastigotes undergo metacy- clogenesis to nonreplicative metacyclic trypomastigotes inside blood-sucking vector digestive tract. T. cruzi species is highly heterogeneous, consisting of populations that present variable molecular repertoire and epidemio- logical characteristics (reviewed by Momen 1999; Buscaglia and Di Noia 2003), concerning growth kinetics, virulence, tissue tropism in mice, in vitro drug resistance and vectorial transmissibility (Dvorak 1984; Laurent et al. 1997; Revollo et al. 1998; De Lana et al. 2000). The clonal population structure organization proposed to T. cruzi (Tibayrenc et al. 1986) accounts for this high variability. The identification of isoenzyme patterns and DNA molecular markers, such as 24Sα rRNA gene and the intergenic region of the mini-exon (Souto et al. 1996; Zingales et al. 1998), led to the separation of T. cruzi populations into two major phylogenetic groups. The denomination of such groups as T. cruzi I and T. cruzi II (TCI and TCII, respectively) is a result of consensus reached by specialists (Anonymous 1999). There is a tendency to associate TCI genotype mainly to sylvatic transmission cycle and TCII genotype to domestic trans- mission cycle (Buscaglia and Di Noia 2003). However, it has been demonstrated that both T. cruzi genotypes (TCI and TCII) have an ample range of wild hosts (rodents, marsupials, edentates, primates, bats, and carnivores). Moreover, TCII in the wild seems to be more focally transmitted in restricted and narrower habitats, while TCI has a broader range of dispersion (Lisboa et al. 2007). Besides, no correlation between parasite main TCI and P. Fampa : M. I. Ramirez (*) Laboratório de Biologia Molecular de Parasitas e Vetores, Instituto Oswaldo Cruz, Fiocruz, Av. Brasil, 4365, 21045-900 Rio de Janeiro, Brazil e-mail: marcelr@ioc.fiocruz.br A. L. S. Santos Laboratório de Estudos Integrados em Bioquímica Microbiana, Departamento de Microbiologia Geral, Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro (UFRJ), Ilha do Fundão, 21941-902 Rio de Janeiro, Brazil Parasitol Res (2010) 107:443–447 DOI 10.1007/s00436-010-1888-9