Diversidade Morfológica, Biológica e Genética, e Rela{\c c}ões Filogenéticas de Tripanossomas de Morcegos do Brasil e Mo{\c c}ambique (áfrica)

Although it has been known for more than 100 years that bats harbour a variety of trypanosomes from the subgenera Schizotrypanum, Megatrypanum and Herpetosoma, our knowledge regarding the genetic diversity, host range, vectors, life cycles, geographical distribution and phylogenetic relationships of these trypanosomes is restricted to a few species. Because the majority of bat trypanosomes were classified exclusively based on morphology, their taxonomy remains problematic and have been phylogenetically revised. Comparison of eco-geographical patterns of trypanosomes and bats can be helpful in evaluating scenarios that could account for the diversity, relationships and current distribution of bat trypanosomes.In this study, the genetic diversity and phylogeographical patterns of trypanosomes that infect Brazilian bats were evaluated by examining 1043 bats from 63 species of 7 families captured in Amazonia, the Pantanal, Cerrado and the Atlantic Forest. The prevalence of trypanosome-infected bats as estimated by haemoculture was 12.9%, resulting in 77 cultures. Most cultures were morphologically and molecularly identified as Schizotrypanum spp. Phylogenetic analyses of SSUrRNA, gGAPDH and Cyt b genes revealed three subclades, T. dionisii, T. c. marinkellei and T. cruzi, all clustering together forming the clade Schizotrypanum. T. dionisii (32.4%) infected bats from 4 families captured in all biomes; T. c. marinkellei (49.3%) was restricted to phyllostomids from Amazonia to the Pantanal. T. cruzi (18.2%) was found mainly in vespertilionids and phyllostomids from the Pantanal/Cerrado and the Atlantic Forest, with a few isolates from Amazonia. Therefore, bat trypanosomes were related to theirs vectors, and the evolutionary history, ecology and phylogeography of the hosts.T. cruzi is a complex of genetically heterogeneous isolates distributed in six discrete typing units (DTUs TcI-VI), more phylogenetically related to T. c. marinkellei than to T. dionisii. Phylogenetic relationships positioned all Amazonian bat isolates into TcI while isolates from Central and Southeast regions constituted the new genotype Tcbat, which lacked virulence and yielded low parasitaemias in mice. Tcbat was found only in bats from anthropic environments, confirming bats as important reservoirs and potential source of T. cruzi infections to humans. Our findings corroborated that the complexity of T. cruzi is larger than currently known.Only bat Schizotrypanum spp. from South America and Europe have been characterised, alleged species from Australia and Africa still lack phylogenetic evidence. We characterized 6 isolates from bats (Molossidae) captured in Mozambique. Morphological and behaviour features were all typical of T. cruzi-like. All the isolates constituted a homogenous clade within the Schizotrypanum by phylogenetic analysis of SSUrRNA, gGAPDH, ITS1 rDNA and SL sequences. Comparable distances separated this new species from their closest species, T. c. marinkellei and T. dionisii, while T. cruzi was separated by larger distances. These findings supported these trypanosomes as a new species, T. erneyi, the first molecularly characterised from African bats. Schizotrypanum trypanosomes and bats are tightly united in a striking example of an ancient and intimate host-parasite partnership. The existence of T. erneyi in Africa sheds new light on the diversity and evolutionary history of Schizotrypanum, providing new insights into the understanding of the origin and evolution of T. cruzi, which speculatively could have evolved from a bat-restricted trypanosome or vice versa.T. rangeli is a non-pathogenic parasite of man and domestic and wild animals in Central and South America transmitted by triatomines, which share hosts and overlapped distribution with T. cruzi. This species has never confidently been described in bats. Previous analyses demonstrated that T. rangeli comprised 4 phylogenetic lineages (A-D). Here, we characterized two isolates of T. rangeli from Brazilian bats, one assigned to lineage A and other to the new lineage E. These isolates are the earliest T. rangeli from bats molecularly characterized, and the reference-isolates of the lineage E.We also characterized morphologically, biologically and phylogenetically 12 isolates from African rhinolophid microbats from Mozambique. The isolates showed blood trypomastigotes typical of the subgenus Megatrypanum, which have been questioned phylogenetically. However, culture and biological features separated the new bat isolates from Schizotrypanum, and SSUrRNA and gGAPDH phylogenies revealed that they are distant from all trypanosomes, prompting the description of a new species that could not be positioned within any subgenus.Cathepsin L-like (CATL) enzymes are cysteine proteases that play a vital role in the metabolism, infectivity, cell differentiation, immunity and pathogenicity of trypanosomes, and have been exploited as potential targets for drugs, vaccines and diagnoses. An understanding of CATL evolutionary relationships can assist in clarifying the role of these enzymes in the parasite life cycles and pathogeneses. Phylogenetic analysis of CATL sequences from 17 isolates representative of the genetic diversity and geographical range of T. rangeli supported the lineages previously established, corroborating independent cycles and divergence associated with sympatric species of Rhodnius. In addition, CATL proved to be excellent targets for diagnosis and genotyping of T. rangeli. We also compared cruzipain (major CATL from T. cruzi) encoding genes from T. cruzi isolates representative of the overall biological, genetic and pathological diversity. Conserved genes are found within and among isolates of the same DTU, excepting TcV-VI that showed polymorphic sequences supporting hybridization origin. Analyses of cruzipain from T. cruzi DTUs and homologues from T. cruzi-like disclosed species- and lineage-specific polymorphisms valuable to understand host-parasite interactions and crucial for evaluation of cruzipain as target for diagnostic, drugs and vaccine approaches. Genealogies of cruzipain encoding genes agree with the diversity and phylogenetic relationships of trypanosome species and T. cruzi DTUs.Further analyses aiming better-resolved phylogenies and reliable molecular-clock model to estimate divergence times are required to infer the most likely hypothesis for the evolutionary history of bat trypanosomes.