Survey of Trypanosoma and Leishmania in wild and domestic animals in an Atlantic rainforest fragment and surroundings in the state of Espírito Santo, Brazil

Leishmania species infection of bats: A systematic review

A wide variety of mammals, including domestic and wild species, have been considered potential hosts and reservoirs for Leishmania. Bats have longevity, dispersal capacity, and adaptability to synotropic environments, characteristics that may favor their role in maintaining the life cycle of parasites. Therefore, the objective of this study was to carry out a worldwide systematic review of the occurrence of Leishmania species in bats, as well as to identify associations between eating habits and the type of sample collected with the occurrence of the infection. Data were obtained from a bibliographic search for studies that used molecular methods to identify parasites, employing the keywords "bats" AND "Leishmania" and their synonyms. We found 68 original studies, of which 20 were included in this review. Most studies were conducted in Brazil (60 %) and only 10 % were conducted in Old World countries. In all, 48 bat species were recorded that hosted seven Leishmania species, resulting in 62 different host-parasite interactions, and the Leishmania infantum interaction with bat species presented higher frequency. There was no significant difference between Leishmania species richness, infection percentage, and type of sample analyzed, but in general, it is observed that the use of different biological samples seems to expand the possibility of parasite detection. The patterns observed here indicate that bats can become infected with a wide variety of Leishmania species and likely play an important role in maintaining the parasite's life cycle. Thus, we suggest that studies aimed at understanding the transmission cycle of leishmaniasis include the investigation of bats as potential hosts or reservoirs of Leishmania.

The Mite Steatonyssus periblepharus Is a Novel Potential Vector of the Bat Parasite Trypanosoma dionisii

Trypanosoma dionisii, for which only bat bugs (Cimicidae) had previously been demonstrated as vectors, was, for the first time, detected in the gamasine mite Steatonyssus periblepharus in Russia. The molecular phylogenetic analysis indicated that trypanosomes found in these mites belong to the "clade A" of T. dionisii, which, based on genetic distances, can be considered as a species separate from the sister clade B, and according to available data also has a distinct geographic distribution. The presence of developmental forms of T. dionisii resembling those previously described during the development of this trypanosome in cimicids suggests that S. periblepharus is a novel vector of the studied trypanosome.

Role of Brazilian bats in the epidemiological cycle of potentially zoonotic pathogens

Bats (Chiroptera) are flying mammals of great biodiversity and habits. These characteristics contribute for them being natural reservoirs and part of the epidemiological cycle of several potentially zoonotic pathogens, such as viruses, protozoa, fungi and bacteria. Brazil hosts approximately 15% of the world's bat diversity, with 181 distinct species, 68 genera and 9 families. About 60% of infectious diseases in humans are of zoonotic origin and, in the last decades, the detection of zoonotic pathogens in bats and their environment has been reported, such as Rabies virus (RABV) and Histoplasma capsulatum. Thus, the aim of this work was to review the reports of zoonotic pathogens associated with bats in Brazil in the past ten years. We reviewed the main pathogenic microorganisms described and the species of bats most frequently involved in the epidemiological cycles of these zoonotic agents. The obtained data show an upward trend in the detection of zoonotic pathogens in Brazilian bats, such as RABV, Bartonella sp., Histoplasma capsulatum and Leishmania spp., with emphasis on the bat species Artibeus lituratus, Carollia perspicillata, Desmodus rotundus and Molossus molossus. These findings highlight the importance of monitoring bat-associated microrganisms to early identify pathogens that may threaten bat populations, including potentially zoonotic microrganisms, emphasizing the importance of the One Health approach to prevent and mitigate the risks of the emergence of zoonotic diseases.

Uncovering Pseudogenes and Intergenic Protein-coding Sequences in TriTryps' Genomes

Trypanosomatids belong to a remarkable group of unicellular, parasitic organisms of the order Kinetoplastida, an early diverging branch of the phylogenetic tree of eukaryotes, exhibiting intriguing biological characteristics affecting gene expression (intronless polycistronic transcription, trans-splicing, and RNA editing), metabolism, surface molecules, and organelles (compartmentalization of glycolysis, variation of the surface molecules, and unique mitochondrial DNA), cell biology and life cycle (phagocytic vacuoles evasion and intricate patterns of cell morphogenesis). With numerous genomic-scale data of several trypanosomatids becoming available since 2005 (genomes, transcriptomes, and proteomes), the scientific community can further investigate the mechanisms underlying these unusual features and address other unexplored phenomena possibly revealing biological aspects of the early evolution of eukaryotes. One fundamental aspect comprises the processes and mechanisms involved in the acquisition and loss of genes throughout the evolutionary history of these primitive microorganisms. Here, we present a comprehensive in silico analysis of pseudogenes in three major representatives of this group: Leishmania major, Trypanosoma brucei, and Trypanosoma cruzi. Pseudogenes, DNA segments originating from altered genes that lost their original function, are genomic relics that can offer an essential record of the evolutionary history of functional genes, as well as clues about the dynamics and evolution of hosting genomes. Scanning these genomes with functional proteins as proxies to reveal intergenic regions with protein-coding features, relying on a customized threshold to distinguish statistically and biologically significant sequence similarities, and reassembling remnant sequences from their debris, we found thousands of pseudogenes and hundreds of open reading frames, with particular characteristics in each trypanosomatid: mutation profile, number, content, density, codon bias, average size, single- or multi-copy gene origin, number and type of mutations, putative primitive function, and transcriptional activity. These features suggest a common process of pseudogene formation, different patterns of pseudogene evolution and extant biological functions, and/or distinct genome organization undertaken by those parasites during evolution, as well as different evolutionary and/or selective pressures acting on distinct lineages.

Molecular detection of Trypanosoma (Trypanosomatidae) in bats from Thailand, with their phylogenetic relationships

The vast majority of trypanosome species is vector-borne parasites, with some of them being medically and veterinary important (such as Trypanosoma cruzi and Trypanosoma brucei) and capable of causing serious illness in vertebrate hosts. The discovery of trypanosomes in bats emphasizes the importance of bats as an important reservoir. Interestingly, there is a hypothesis that bats are ancestral hosts of T. cruzi. Trypanosome diversity has never been investigated in bats in Thailand, despite being in a biodiversity hot spot. To gain a better understanding of the diversity and evolutionary relationship of trypanosomes, polymerase chain reaction-based surveys were carried out from 2018 to 2020 in 17 sites. A total of 576 bats were captured, representing 23 species. A total of 38 (6.6%) positive samples was detected in ten bat species. Trypanosoma dionisii and Trypanosoma noyesi were identified from Myotis siligorensis and Megaderma spasma, respectively. The remaining 18S rRNA sequences of trypanosomes were related to other trypanosomes previously reported elsewhere. The sequences in the current study showed nucleotide identity as low as 90.74% compared to those of trypanosomes in the GenBank database, indicating the possibility of new species. All bat trypanosomes identified in the current study fall within the T. cruzi clade. The current study adds to evidence linking T. noyesi to a bat trypanosome and further supports the bat host origin of the T. cruzi clade. To the best of authors' knowledge, this is the first study on bat trypanosomes in Thailand and their phylogenetic relationships with global isolates.

"Visiting old, learn new": taxonomical overview of chiropteran trypanosomes from the morphology to the genes

Bats (the order Chiroptera) account for more than 20% of all mammalian species in the world; remarkably, they are the only mammals capable of true and sustained flight using their wing-like forelimbs. Since the beginning of the twentieth century, various morphotypes (or genotypes in the last decade) of haemoflagellates in the genus Trypanosoma (Euglenozoa: Kinetoplastea: Trypanosomatidae) have been reported worldwide in the blood of bats. Of note, the latent nature of chiropteran trypanosome infection with low levels of parasitaemia, together with the apparent morphological variation of the bloodstream forms related to phenotypical plasticity and the morphological resemblance of different parasite species, has hampered the taxonomic classification of bat trypanosomes based on morphological criteria. This said, 50 years ago, Hoare (1972) provisionally divided bat trypanosomes into two major morphotypes: the megadermae group (corresponding to the subgenus Megatrypanum in the traditional taxonomic system; 8 species) and the vespertilionis group (similar to the subgenus Schizotrypanum; 5 species). Importantly, the biological and biochemical analyses of bat trypanosomes isolated by haemoculture, together with the molecular genetic characterisation using various gene markers, allowed the establishment of clear phylogenetic and taxonomic relationships of various isolates from different continents in the last two decades. Here, we review the historical taxonomic approaches used to define chiropteran trypanosomes, as well as the ones currently employed to shed light on the diversity and evolutional tracks of the globally distributed chiropteran trypanosomes.

Biological and Genetic Heterogeneity in Trypanosoma dionisii Isolates from Hematophagous and Insectivorous Bats

This study describes the morphological, biochemical, and molecular differences among Trypanosoma dionisii isolates from hemocultures of hematophagous (Desmodus rotundus; n = 2) and insectivorous (Lonchorhina aurita; n = 1) bats from the Atlantic Rainforest of Rio de Janeiro, Brazil. Fusiform epimastigotes from the hematophagous isolates were elongated, whereas those of the insectivorous isolate were stumpy, reflected in statistically evident differences in the cell body and flagellum lengths. In the hemocultures, a higher percentage of trypomastigote forms (60%) was observed in the hematophagous bat isolates than that in the isolate from the insectivorous bat (4%), which demonstrated globular morphology. Three molecular DNA regions were analyzed: V7V8 (18S rDNA), glycosomal glyceraldehyde 3-phosphate dehydrogenase gene, and mitochondrial cytochrome b gene. The samples were also subjected to multilocus enzyme electrophoresis and random amplified polymorphic DNA analysis. All isolates were identified as T. dionisii by phylogenetic analysis. These sequences were clustered into two separate subgroups with high bootstrap values according to the feeding habits of the bats from which the parasites were isolated. However, other T. dionisii samples from bats with different feeding habits were found in the same branch. These results support the separation of the three isolates into two subgroups, demonstrating that different subpopulations of T. dionisii circulate among bats.

Clinical aspects and diagnosis of leishmaniasis in equids: a systematic review and meta-analysis

Leishmaniases are a group of diseases of zoonotic importance caused by over 20 species of protozoa of the genus Leishmania, in which domestic dogs are considered to be the main reservoir for the disease. However, the involvement of other vertebrates as reservoirs for these parasites has also been investigated. Therefore, the objective of the present study was to carry out a systematic review with meta-analysis on occurrences of leishmaniasis in equids. The case reports described animals with cutaneous symptoms of leishmaniasis (papules, nodules, ulcers or crusts) that regressed spontaneously, located mainly on the head and limbs, from which three species of protozoa were identified in the lesions: Leishmania braziliensis, Leishmania infantum and Leishmania siamensis. In turn, the meta-analysis showed a combined prevalence of 25%, although with high heterogeneity among the studies, which was attributed to the use of different methods for diagnosing the disease. Leishmaniasis in equids is a benign disease but it should be included in the differential diagnosis of cutaneous diseases among these species. Seroepidemiological studies are important in investigating and monitoring suspected exposure of these hosts to the parasite, especially in endemic areas. However, there is also a need to standardize diagnostic methods.

Isolation and characterization of trypanosomatids, including Crithidia mellificae, in bats from the Atlantic Forest of Rio de Janeiro, Brazil

We studied infection by Trypanosomatidae in bats captured in two areas with different degradation levels in the Atlantic Forest of Rio de Janeiro state: Reserva Ecológica de Guapiaçu (REGUA) and Estação Fiocruz Mata Atlântica (EFMA). Furthermore, we evaluated whether the diversity of trypanosomatids changes according to bat diversity and the different levels of preservation in the region. The results showed no influence of the level of preservation on bat species richness (15 and 14 species, respectively), with similar chiropterofauna and higher abundance of two common fruit-eating bat species in the tropics: Carollia perspicillata and Artibeus lituratus. Of the 181 bat specimens analyzed by LIT/Schneider hemoculture, we detected 24 infected individuals (13%), including one positive Sturnira lilium individual that was also positive by fresh blood examination. Molecular characterization using nested PCR targeting the 18 SSU rRNA-encoding gene fragment showed similar trypanosomatid infection rates in bats from the two areas: 15% in REGUA and 11% in EFMA (p = 0.46). Trypanosoma dionisii was the most frequently detected parasite (54%), followed by T. cruzi DTUs TcI and TcIV and Trypanosoma sp., in Neotropical phyllostomid bats (RNMO63 and RNMO56); mixed infections by T. dionisii/T. cruzi TcIII and T. dionisii/T. cruzi TcI were also observed. The T. cruzi DTUs TcI and TcIV are the genotypes currently involved in cases of acute Chagas disease in Brazil, and T. dionisii was recently found in the heart tissue of an infected child. Surprisingly, we also describe for the first time Crithidia mellificae, a putative monoxenous parasite from insects, infecting a vertebrate host in the Americas. Bats from the Atlantic Forest of Rio de Janeiro state harbor a great diversity of trypanosomatids, maintaining trypanosomatid diversity in this sylvatic environment.

Bat trypanosomes from Tapajós-Arapiuns Extractive Reserve in Brazilian Amazon

Trypanosoma comprises flagellates able to infect several mammalian species and is transmitted by several groups of invertebrates. The order Chiroptera can be infected by the subgenera Herpetosoma, Schizotrypanum, Megatrypanum and Trypanozoon. In this study, we described the diversity of bat trypanosomes and inferred phylogenetic relationships among the trypanosomes from bats caught in Tapajós-Arapiuns Extractive Reserve (Resex) in Pará state. Trypanosomes from bats were isolated by means of hemoculture, and the molecular phylogeny was based on the trypanosome barcode (SSUrDNA V7V8 variable region). A total of 111 bats were caught in the area, belonging to three families (Emballonuridae, Molossidae and Phyllostomidae) and 12 species. The bat trypanosome prevalence, as evaluated through hemoculture, was 9% all positive cultures were cryopreserve (100% of isolation success). Phylogenetic trees grouped nine isolates in T. cruzi marinkellei branch and only one in T. dionisii branch. Studies on bat trypanosome diversity are important for identifying pathogenic species and for generating support for control measures, especially in such areas where humans inhabit the forest with close contact with bat species. In addition, this is the first study in Resex Tapajós-Arapiuns extractive reserve and further studies should be conducted to elucidate the role of these parasites as environmental degradation biomarkers.

High frequency of trypanosomatids in gallery forest bats of a Neotropical savanna

Bats are well-known hosts of trypanosomatids, though information about their role as reservoirs of these protozoans in the Brazilian savanna is poorly known. We aimed to analyze the occurrence of trypanosomatid species in bats occurring in remnants of gallery forests of Brasília, Federal District of Brazil. We sampled bats using mist nets in six sites, and we collected blood, wing fragments and oral swab samples from all captured individuals. Trypanosomatids were identified in the captured bats through sequencing of the SSUrRNA region and kDNA qPCR. We found no parasite in blood smears of 146 individuals of 14 species captured, but blood cultures were positive for nine bats. We detected trypanosomatids molecularly in 111 (76%) specimens of all bat species in the studied areas. Most of the infected bats had Leishmania-like DNA detected in blood and swab samples of the oral mucosa. We distinguished three species of Trypanosoma (Trypanosoma dionisii, T. rangeli and T. cruzi) in Carollia perspicillata. SSUrRNA PCR of oral samples is a non-invasive and practical method for identification of trypanosomatid species in bats. Our results support our belief that bats could be potential reservoirs for Trypanosoma and Leishmania-like species in the enzootic cycle of these parasites in gallery forests of the Brazilian Cerrado biome.

New Trypanosoma species, Trypanosoma gennarii sp. nov., from South American marsupial in Brazilian Cerrado

Hundreds of trypanosome species have been described in all mammalian orders, on every continent, including with mixed infections. Trypanosomes circulate in the form of sylvatic enzootic infections transmitted by blood-sucking insects that are associated with the host mammals. Small wild mammals were caught in a fragment of Cerrado terrain on an island in the hydroelectric reservoir of Três Marias, in the central region of the state of Minas Gerais, using pitfall and Sherman traps with different means of attraction. DNA samples from these mammals were subjected to the conventional polymerase chain reaction (PCR) for the full-length genes SSU rDNA and gGAPDH. A total of 232 animals of the orders Didelphimorphia, Rodentia, Chiroptera and Cingulata were caught (total of 17 species). There were also four species of marsupials: Monodelphis domestica, Didelphis albiventris, Gralicinanus agilis and Micoureus paraguaianus. Among these, there were eight positive individuals of Monodelphis domestica. However, nine cultures were established, because one of them was parasitized by two species of trypanosomes: Trypanosoma cruzi and a new trypanosome species. The new species have a large epimastigote forms, and with a well-developed undulating membrane in trypomastigote forms. The new species Trypanosoma gennarii was described in Monodelphis domestica.

Occurrence of Neospora caninum and Toxoplasma gondii antibodies in dogs from rural properties surrounding a biological reserve, Espirito Santo, Brasil

The aim of this study was to determine the presence of antibodies to Neospora caninum and Toxoplasma gondii in serum samples of 187 dogs from 30 rural properties surrounding Córrego do Veado Biological Reserve, Espírito Santo State, Brazil. The Reserve is one of the last lowland Atlantic Forest remnants of the region, surrounded by agriculture farms and cattle pastures. The presence of IgG antibodies was determined by the Indirect Fluorescent Antibody Test for T. gondii (cut-off 1:16) and N. caninum (cut-off 1:50). Positive samples were diluted 2-fold until the last positive dilution. Antibodies to T. gondii were found in 77 (47.05%) dogs and antibodies to N. caninum in 22 dogs (11.76%) and one only dog was positive for both infections. No association between T. gondii and N. caninum infection and sex was observed (p>0.05). Control measures to prevent those infections in dogs that living surrounding the reserve and that had contact with wild animals are important to avoid the introduction of N. caninum in wild animals. This was the first study of frequency of occurrence of T. gondii and N. caninum in dogs from Espírito Santo, Brazil.

Diversity of bats trypanosomes in hydroeletric area of Belo Monte in Brazilian Amazonia

The Trypanosoma comprises flagellates able to infect many mammalian species and is transmitted by several groups of invertebrates. The order Chiroptera can be infected by the subgenera Herpetosoma, Schizotrypanum, Megatrypanum and Trypanozoon. In this study, we described the diversity of bats trypanosomes, inferring the phylogenetic relationships among the trypanosomes from bats caught Belo Monte Hydroeletric area (Brazilian Amazonia). Trypanosomes from bats were isolated by haemoculture, and the molecular phylogeny based on small subunit rDNA (SSU rDNA) and glycosomal-3-phosphate dehydrogenase (gGAPDH) gene sequences. Morphological characterization included light and scanning electron microscopy. A total of 157 bats were caught in the area belonging 6 Families (Emballonuridae, Furipteridae, Mormoopidae, Natalidae, Phyllostomidae and Vespertilionidae) and 34 species. The bat trypanosome prevalence, as evaluated through haemoculture, was 5,7%. Phylogenetic trees grouped the isolates in T. cruzi branch (TCI and TCbat lineage), T. cruzi marinkellei and Trypanosoma wauwau from Pteronotus parnellii. This is the first isolate from T. wauwau in Para state. The occurrence of T. cruzi in the ​​ Belo Monte Hydroeletric area (UHE Belo Monte) in Amazon/Brazil attentive to the risk of migration human population required for the works of the dam and new cities that grow in the vicinity of these businesses, but it is a zoonosis already known to the Amazon region, and the presence of unclassified Trypanosoma species, attend to the large parasitic biodiversity still unknown.

Ecological scenario and Trypanosoma cruzi DTU characterization of a fatal acute Chagas disease case transmitted orally (Espírito Santo state, Brazil)

BACKGROUND

Trypanosoma cruzi infection via oral route results in outbreaks or cases of acute Chagas disease (ACD) in different Brazilian regions and poses a novel epidemiological scenario. In the Espírito Santo state (southeastern Brazil), a fatal case of a patient with ACD led us to investigate the enzootic scenario to avoid the development of new cases. At the studied locality, Triatoma vitticeps exhibited high T. cruzi infection rates and frequently invaded residences.

METHODS

Sylvatic and domestic mammals in the Rio da Prata locality, where the ACD case occurred, and in four surrounding areas (Baia Nova, Buenos Aires, Santa Rita and Todos os Santos) were examined and underwent parasitological and serological tests. Triatomines were collected for a fecal material exam, culturing and mini-exon gene molecular characterization, followed by RFLP-PCR of H3/Alul. Paraffin-embedded cardiac tissue of a patient was washed with xylene to remove paraffin and DNA was extracted using the phenol-chloroform method. For genotype characterization, PCR was performed to amplify the 1f8, GPI and 18S rRNA genes. In the case of V7V8 SSU rRNA, the PCR products were molecularly cloned. PCR products were sequenced and compared to sequences in GenBank. Phylogenetic analysis using maximum likelihood method with 1000 bootstrap replicates was performed.

RESULTS

None of the animals showed positive hemocultures. Three rodents and two dogs showed signs of infection, as inferred from borderline serological titers. T. vitticeps was the only triatomine species identified and showed T. cruzi infection by DTUs TcI and TcIV. The analysis of cardiac tissue DNA showed mixed infection by T. cruzi (DTUs I, II, III and IV) and Trypanosoma dionisii.

CONCLUSIONS

Each case or outbreak of ACD should be analyzed as a particular epidemiological occurrence. The results indicated that mixed infections in humans may play a role in pathogenicity and may be more common than is currently recognized. Direct molecular characterization from biological samples is essential because this procedure avoids parasite selection. T. dionisii may under certain and unknown circumstances infect humans. The distribution of T. cruzi DTUS TcIII and TcIV in Brazilian biomes is broader than has been assumed to date.

Trypanosoma cruzi and Leishmania infantum chagasi Infection in Wild Mammals from Maranhão State, Brazil

Trypanosoma and Leishmania are obligate parasites that cause important diseases in human and domestic animals. Wild mammals are the natural reservoirs of these parasites, which are transmitted by hematophagous arthropods. The present study aimed to detect the natural occurrence of trypanosomatids through serological diagnosis, PCR of whole blood and blood culture (hemoculture), and phylogenetic relationships using small subunit ribosomal DNA (SSU rDNA), cytochrome b, and glycosomal glyceraldehyde 3-phosphate dehydrogenase (gGAPDH) genes. Samples from 131 wild animals, including rodents, marsupials, and bats, were sampled in six areas in the state of Maranhão, in a transition zone of semiarid climates northeast of the equatorial humid Amazon. Serological analysis for Leishmania (Leishmania) infantum chagasi was performed in opossums by indirect fluorescent antibody test (IFAT), and all animals were serologically negative. Nine positive hemocultures (6.77%) were isolated and cryopreserved and from mammals of the Didelphimorphia and Chiroptera orders and positioned in phylogenies on the basis of sequences from different genes with reference strains of Trypanosoma cruzi marinkellei and T. cruzi. From primary samples (blood and tissues) only one bat, Pteronotus parnellii, was positive to SSU rDNA and gGAPDH genes and grouped with the L. infantum chagasi branch. The studies conducted in Maranhão State provide knowledge of parasite diversity. It is important to determine the presence of trypanosomatids in wild mammals with synanthropic habits.