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Background: Trypanosoma cruzi, the agent of Chagas disease in humans, has a vast reservoir of mammalian hosts in the Americas, and is classified into six genetic lineages, TcI-TcVI, with a possible seventh, TcBat. Elucidating enzootic cycles of the different lineages is important for understanding the ecology of this parasite, the emergence of new outbreaks of Chagas disease and for guiding control strategies. Direct lineage identification by genotyping is hampered by limitations of parasite isolation and culture. An indirect method is to identify lineage-specific serological reactions in infected individuals; here we describe its application with sylvatic Brazilian primates., Methods: Synthetic peptides representing lineage-specific epitopes of the T. cruzi surface protein TSSA were used in ELISA with sera from Atlantic Forest Leontopithecus chrysomelas (golden-headed lion tamarin), L. rosalia (golden lion tamarin), Amazonian Sapajus libidinosus (black-striped capuchin) and Alouatta belzebul (red-handed howler monkey)., Results: The epitope common to lineages TcII, TcV and TcVI was recognised by sera from 15 of 26 L. chrysomelas and 8 of 13 L. rosalia. For 12 of these serologically identified TcII infections, the identity of the lineage infection was confirmed by genotyping T. cruzi isolates. Of the TcII/TcV/TcVI positive sera 12 of the 15 L. chrysomelas and 2 of the 8 L. rosalia also reacted with the specific epitope restricted to TcV and TcVI. Sera from one of six S. libidinous recognised the TcIV/TcIII epitopes., Conclusions: This lineage-specific serological surveillance has verified that Atlantic Forest primates are reservoir hosts of at least TcII, and probably TcV and TcVI, commonly associated with severe Chagas disease in the southern cone region of South America. With appropriate reagents, this novel methodology is readily applicable to a wide range of mammal species and reservoir host discovery.

The black lion tamarin, Leontopithecus chrysopygus, is endemic to the Atlantic Forest of the interior of the state of São Paulo in Brazil. Since the discovery of the species, authors have described variations in the pelage of L. chrysopygus, but the nature of this variation has remained unknown. We examined museum specimens and living animals to see if the pelage of L. chrysopygus varies individually, geographically or ontogenetically. We reviewed all known locality records of the species, and concluded that the pelage of L. chrysopygus varies individually and ontogenetically, but not geographically. The extent of the golden chromogenetic fields is larger in younger individuals, and the pelage becomes darker after successive moults. We examined 2 juveniles that presented a pelage similar to adult L. caissara. Geographically, there is a clear break in the phenotypes attributed to L. caissara and L. chrysopygus, precluding clinal variation and corroborating the specific status of the former. The separation between these 2 species is coincident with a tectonic fault known as the 'Guapiara lineament', and may have been caused by a recent activation of this geological formation. We also suggest a historical contact zone between L. chrysopygus and the marmoset Callithrix aurita in the upper Rio Tietê region., (© 2016 S. Karger AG, Basel.)

Here, we present a review of the dataset resulting from the 11-years follow-up of Trypanosoma cruzi infection in free-ranging populations of Leontopithecus rosalia (golden lion tamarin) and Leontopithecus chrysomelas (golden-headed lion tamarin) from distinct forest fragments in Atlantic Coastal Rainforest. Additionally, we present new data regarding T. cruzi infection of small mammals (rodents and marsupials) that live in the same areas as golden lion tamarins and characterisation at discrete typing unit (DTU) level of 77 of these isolates. DTU TcII was found to exclusively infect primates, while TcI infected Didelphis aurita and lion tamarins. The majority of T. cruzi isolates derived from L. rosalia were shown to be TcII (33 out 42) Nine T. cruzi isolates displayed a TcI profile. Golden-headed lion tamarins demonstrated to be excellent reservoirs of TcII, as 24 of 26 T. cruzi isolates exhibited the TcII profile. We concluded the following: (i) the transmission cycle of T. cruzi in a same host species and forest fragment is modified over time, (ii) the infectivity competence of the golden lion tamarin population fluctuates in waves that peak every other year and (iii) both golden and golden-headed lion tamarins are able to maintain long-lasting infections by TcII and TcI.

The ability of a population to evolve in a changing environment may be compromised by human-imposed barriers to gene flow. We investigated the population structure and the possible occurrence of a genetic bottleneck in two isolated populations of the black-faced lion tamarin (Leontopithecus caissara), a species with very reduced numbers (less than 400) in a very restricted range in the Atlantic Forest of southeast Brazil. We determined the genotypes of 52 individuals across 9 microsatellite loci. We found genetic divergence between the populations, each exhibiting low genetic diversity. Analysis revealed broad- and fine-scale population structuring. Both populations have evidently experienced population reduction and a genetic bottleneck without presenting any apparent detrimental effect. Anyway, measures should be taken to effectively protect the forests where L. caissara occurs in order to allow its populations to increase and counteract the eventual effects of genetic impoverishment., (Copyright © 2012 S. Karger AG, Basel.)

The parasite prevalence and infection intensity in primate wild populations can be affected by many variables linked to host and/or parasite ecology or either to interparasite competition/mutualism. In this study, we tested how host sex, age, and place of origin, as well parasitic concomitant infections affect the structure of golden lion and golden-headed lion tamarins parasite community, considering Trypanosoma cruzi and intestinal helminths infection in these primates. A total of 206 tamarins from two Atlantic Coastal rain forest areas in Brazil were tested during 4 years for prevalence of T. cruzi infection and helminth prevalence. Three intestinal helminth groups showed high prevalences in both tamarin species: Prosthenorchis sp., Spiruridae, and Trichostrongylidae. An association between presence of T. cruzi infection and higher intestinal helminth prevalence was found in both tamarin species. Two explanations for this association seem to be plausible: (1) lower helminth-linked mortality rates in T. cruzi-infected tamarins and (2) lower elimination rates of helminths in such tamarins. A higher frequency of T. cruzi-positive blood cultures was significantly correlated to female tamarins and to the presence of Trichostrongylidae infection. The possibility of an increase in the transmissibility of T. cruzi and the three analyzed helminths in lion tamarins with concomitant infections is discussed.