Nubia E. Matta

Blood parasites in some birds from eastern plains of Colombia

A total of 315 birds representing 75 species (23 families) from Villavicencio and San Miguel (Meta, Colombia) were examined for haematozoa. Fifty birds (15.9%) harbored blood parasites. Microfilariae were the most common haematozoans encountered, followed by species of the genera Haemoproteus, Plasmodium and Trypanosoma. This survey included 15 new host-parasite records and 8 species of birds that were examined for haematozoa for the first time. The prevalence registered in this research was similar to others recorded in the Neotropical region, but in sharp contrast with the prevalence of blood parasites in other major land masses.

Mixed species flock, nest height, and elevation partially explain avian haemoparasite prevalence in Colombia

The high avian biodiversity present in the Neotropical region offers a great opportunity to explore the ecology of host-parasite relationships. We present a survey of avian haemoparasites in a megadiverse country and explore how parasite prevalences are related to physical and ecological host characteristics. Using light microscopy, we documented the presence of haemoparasites in over 2000 individuals belonging to 246 species of wild birds, from nine localities and several ecosystems of Colombia. We analysed the prevalence of six avian haemoparasite taxa in relation to elevation and the following host traits: nest height, nest type, foraging strata, primary diet, sociality, migratory behaviour, and participation in mixed species flocks. Our analyses indicate significant associations between both mixed species flocks and nest height and Haemoproteus and Leucocytozoon prevalence. The prevalence of Leucocytozoon increased with elevation, whereas the prevalence of Trypanosoma and microfilariae decreased. Plasmodium and Haemoproteus prevalence did not vary significantly with elevation; in fact, both parasites were found up to 3300m above sea level. The distribution of parasite prevalence across the phylogeny of bird species included in this study showed little host phylogenetic signal indicating that infection rates in this system are evolutionarily labile. Vector distribution as well as the biology of transmission and the maintenance of populations of avian haemoparasites deserve more detailed study in this system.

Avian haemosporidians from Neotropical highlands: Evidence from morphological and molecular data.

Avian haemosporidian parasites have been scarcely studied in the Neotropical highlands despite the high avian diversity reported and the uniqueness of these ecosystems. The aims of this study were to examine Haemoproteus and Plasmodium diversity based on morphological and molecular data, as well as to explore the concordance between these two approaches, when identifying species. We sampled 1487 birds belonging to 166 species, in localities of the Colombian Andean region at elevations ranging from 2100 to 4000 m above sea level. Here, we report twelve morphological parasite species, of which five are undescribed. Thirty parasite cytochrome b lineages are reported, 17 of which for the first time. We provide morphological information and illustrations, as well as, cytochrome b lineages for six morphospecies: Haemoproteus columbae, Haemoproteus witti, Haemoproteus coatneyi, Haemoproteus vireonis, Plasmodium lutzi, and Plasmodium unalis. This is the first report to provide a linkage between morphology and a molecular lineage for H. witti. Cytochrome b gene proved to be useful for species determination as DNA barcoding. Differences in parasite composition between lowlands and highlands in Colombia suggest a replacement of avian Plasmodium fauna. Parasite lineages restricted to either Colombian resident or Nearctic migratory birds were found; but a single lineage common in both has not been recorded in Nearctic non-migratory birds. We generated valuable information by using both morphological and molecular data representing competent host-parasite relationships which are based on observation of gametocytes in circulation; and increased the taxon sampling of avian haemosporidian.

Prevalence of blood parasites in Tyrannidae (Flycatchers) in the eastern plains of Colombia

Blood samples from 159 birds of the New-world family Tyrannidae (the flycatchers) from the eastern plains of Colombia, were examined for haematozoa parasites, in 1999-2000. Haematozoa were detected in six of 20 species. The overall prevalence was 10.1%. The most common parasites detected were microfilariae, followed by Trypanosoma and Plasmodium. The highest prevalence (9.6%) was found in the Ochre-bellied Flycatcher (Mionectes oleaginea). Mixed infections with more than one genus of blood parasite were rare and most infections encountered were of low intensity. The results of this study suggest an important role of ecologically diverse conditions determining composition, transmission, and prevalence of a blood parasite fauna, presumably through host interaction population density. Some new host parasite relationship records are presented.

Identification of Plasmodium (Haemamoeba) lutzi (Lucena, 1939) from Turdus fuscater (Great Thrush) in Colombia

Abstract:  This study reports a broadening of the altitudinal range and a new host for Plasmodium (Haemamoeba) lutzi in Colombia. The study was conducted in the city of Bogotá, located in the Eastern Cordillera of Colombia at 2,560 m asl (meters above sea level) with an average annual temperature of 15 C. In total, 156 specimens of birds belonging to 25 species and 14 families were captured using mist nets. The blood samples were collected through venipuncture and analyzed by light microscopy. Plasmodium (H.) lutzi was only found in 2 individuals of Turdus fuscater (Great Thrush). This parasite has previously been reported in Aramides cajaneus (before: Aramides cajanea) (Grey-Necked Wood Rail), a bird found in the lowlands of Brazil, Venezuela, and Colombia. This finding provides evidence for a broad host range for P. lutzi that include 2 different orders, Gruiformes and Passeriformes, and also altitudinal expansion of its distribution. The blood stages were compared with the parasites original descriptions, and the sequence of the parasites mitochondrial genome (mtDNA) confirms that P. lutzi is a sister taxa of Plasmodium relictum, as previously proposed.

Mode and rate of evolution of haemosporidian mitochondrial genomes: Timing the radiation of avian parasites

&NA; Haemosporidians are a diverse group of vector‐borne parasitic protozoa that includes the agents of human malaria; however, most of the described species are found in birds and reptiles. Although our understanding of these parasites’ diversity has expanded by analyses of their mitochondrial genes, there is limited information on these genes’ evolutionary rates. Here, 114 mitochondrial genomes (mtDNA) were studied from species belonging to four genera: Leucocytozoon, Haemoproteus, Hepatocystis, and Plasmodium. Contrary to previous assertions, the mtDNA is phylogenetically informative. The inferred phylogeny showed that, like the genus Plasmodium, the Leucocytozoon and Haemoproteus genera are not monophyletic groups. Although sensitive to the assumptions of the molecular dating method used, the estimated times indicate that the diversification of the avian haemosporidian subgenera/genera took place after the Cretaceous‐Paleogene boundary following the radiation of modern birds. Furthermore, parasite clade differences in mtDNA substitution rates and strength of negative selection were detected. These differences may affect the biological interpretation of mtDNA gene lineages used as a proxy to species in ecological and parasitological investigations. Given that the mitochondria are critically important in the parasite life cycle stages that take place in the vector and that the transmission of parasites belonging to particular clades has been linked to specific insect families/subfamilies, this study suggests that differences in vectors have affected the mode of evolution of haemosporidian mtDNA genes. The observed patterns also suggest that the radiation of haemosporidian parasites may be the result of community‐level evolutionary processes between their vertebrate and invertebrate hosts.

Leucocytozoon fringillinarum and Leucocytozoon dubreuili in Turdus fuscater from a Colombian Páramo Ecosystem

Abstract: Leucocytozoon spp. infections have been rarely studied in Neotropical countries. The apparently low prevalence of these parasites compared to the Nearctic regions suggests the absence of competent vectors; however, a 21.3% overall prevalence has recently been reported in non-migratory birds from the páramo region of Chingaza National Natural Park (NNP), where Turdus fuscater (Great Thrush) is the species most frequently infected by these parasites. The present study provides the descriptions of the Leucocytozoon spp. detected in Great Thrushes trapped in Chingaza NNP. The parasites were confirmed by microscopic examination and PCR of blood, histopathology was also done. Leucocytozoon dubreuili and L. fringillinarum gametocytes were observed in blood smears. The corresponding cytochrome b (cyt b) lineages obtained of L. fringillinarum were closely related to lineages previously found in individuals infecting turdiid species sampled elsewhere. This is one of the few reports analyzing Leucocytozoon spp. infections in resident birds from a Neotropical country.

Leucocytozoon Diversity and Possible Vectors in the Neotropical highlands of Colombia

Studies of the lowland avifauna in the Neotropical Region have shown a paucity of Leucocytozoon species. However, surveys conducted in the Colombian highlands revealed a great diversity of these parasites infecting resident birds. To further investigate the relationship between Leucocytozoon diversity, the potential vectors, and altitudinal distribution, birds from 41 families were sampled at low and high elevations in Colombia. Blood samples were screened by microscopy, and a fragment of cytochrome b was amplified from Leucocytozoon-positive samples. The complete mitochondrial genome was also obtained for each morphospecies of Leucocytozoon. Leucocytozoon species were detected in resident birds, with various degrees of host specificity, at elevations from 2,400 to 3,950 meters above sea level, where five new host-parasite associations were discovered. Phylogenetic analysis based on the cytochrome b fragment suggested that two nominal taxa, L. fringillinarum and L. majoris, are species complexes. Blood sources of Simuliidae revealed generalist-feeding habits that included avian and mammalian hosts. Molecular analysis of parasites in black flies indicated a close relationship with the parasites found in birds. Our investigation provides further evidence that the distribution and transmission of Leucocytozoon species in the Neotropics are influenced by elevation, with the highest prevalence between 2,400 and 3,200 m asl.

Haemoproteus erythrogravidus n. sp. (Haemosporida, Haemoproteidae): Description and molecular characterization of a widespread blood parasite of birds in South America

The great diversity of birds and ecosystems in the Andean mountains has been understudied in terms of their parasite species. We describe a new Haemoproteus parasite, H. (Parahaemoproteus) erythrogravidus infecting Zonotrichia capensis (Rufous-Collared Sparrow) in South America. The description of this blood parasite species is supported by morphological and molecular data based on a fragment of cytochrome b gene (cyt b) and complete mitochondrial genome sequences. The new species is closely related to H. (Parahaemoproteus) coatneyi, and it can be readily distinguished from the latter parasite due to morphology of its blood stages, particularly 1) the formation of a marked protrusion on envelope of infected erythrocytes by the majority of developing gametocytes, a feature which is unique for this Haemoproteus species and 2) the extremely attenuated width of the growing dumbbell-shaped macro- and microgametocytes. Additionally, Haemoproteus erythrogravidus is shown to be a monophyletic taxon that diverges from Haemoproteus coatneyi at the molecular level. We provide the complete mitochondrial DNA genome for both H. coatneyi and H. erythrogravidus. Molecular and morphological evidences indicate that H. erythrogravidus is present in Ecuador and Colombia, and genetic lineages with 100% of identity for the cyt b gene were reported in Chile, Perú, and Venezuela. Our study also indicates that H. erythrogravidus and H. coatneyi are sympatric sister taxa sharing Z. capensis as a host species across its distribution, which could be the result of sympatric speciation or complex biogeographic processes. Further studies on the distribution and evolutionary history of Z. capensis and its parasites H. erythrogravidus and H. coatneyi insight for our better understanding of the factors and dynamics driving parasite speciation.

DIFFERENCES IN THE ANTIGENIC PROFILE AND INFECTIVITY OF MURINE MACROPHAGES OF LEISHMANIA (VIANNIA) PARASITES

Abstract The antigenic profile and infectivity were compared between 3 recent Leishmania (Viannia) isolates from the Amazonian region (Instituto Nacional de Pesquisas da Amazonia [INPA] strains) and 3 World Health Organization (WHO) reference species (Leishmania guyanensis, Leishmania braziliensis, and Leishmania naiffi). Differences were observed in the peak and extent of promastigote growth. The WHO reference strains exhibited significantly higher exponential growth as promastigotes than INPA strains. In the immunoblot analyses, the INPA strains revealed several specific peptide fragments, as well as the greatest recognition frequencies by sera from Leishmania sp.–infected patients; among the latter, antigens derived from L. naiffi were the most frequently recognized. In vitro infection was carried out using mice peritoneal macrophages; all strains were able to enter the macrophages, but only L. amazonensis was able to reproduce. A striking observation was that L. naiffi exhibited the longest survival time inside the macrophages. Our data strongly suggest the application of recently isolated parasites as sources of antigen for diagnosis procedures. Moreover, L. naiffi species possesses several characteristics relevant for its use as a source of novel antigens to be explored in the design of diagnostic tools and vaccines.