Vector-borne transmission of Trypanosoma cruzi among captive Neotropical primates in a Brazilian zoo

Background: Neotropical primates are important sylvatic hosts of Trypanosoma cruzi, the etiological agent of Chagas disease. Infection is often subclinical, but severe disease has been described in both free-ranging and captive primates. Panstrongylus megistus, a major T. cruzi vector, was found infesting a small-primate unit at Brasília zoo (ZooB), Brazil. ZooB lies close to a gallery-forest patch where T. cruzi circulates naturally. Here, we combine parasitological and molecular methods to investigate a focus of T. cruzi infection involving triatomine bugs and Neotropical primates at a zoo located in the Brazilian Savannah. Methods: We assessed T. cruzi infection in vectors using optical microscopy (n = 34) and nested PCR (n = 50). We used quantitative PCR (qPCR) to examine blood samples from 26 primates and necropsy samples from two primates that died during the study. We determined parasite lineages in five vectors and two primates by comparing glucose-6-phosphate isomerase (G6pi) gene sequences. Results: Trypanosoma cruzi was found in 44 vectors and 17 primates (six genera and eight species); one Mico chrysoleucus and one Saguinus niger had high parasitaemias. Trypanosoma cruzi DNA was detected in three primates born to qPCR-negative mothers at ZooB and in the two dead specimens. One Callithrix geoffroyi became qPCR-positive over a two-year follow-up. All G6pi sequences matched T. cruzi lineage TcI. Conclusions: Our findings strongly suggest vector-borne T. cruzi transmission within a small-primate unit at ZooB – with vectors, and perhaps also parasites, presumably coming from nearby gallery forest. Periodic checks for vectors and parasites would help eliminate T. cruzi transmission foci in captive-animal facilities. This should be of special importance for captive-breeding programs involving endangered mammals, and would reduce the risk of accidental T. cruzi transmission to keepers and veterinarians

The role of gallery forests in maintaining Phlebotominae populations: potential Leishmania spp. vectors in the Brazilian savanna

Background: knowledge on synanthropic phlebotomines and their natural infection by Leishmania is necessary for the identification of potential areas for leishmaniasis occurrence. Objective: to analyse the occurrence of Phlebotominae in gallery forests and household units (HUs) in the city of Palmas and to determine the rate of natural infection by trypanosomatids. Methods: gallery forests and adjacent household areas were sampled on July (dry season) and November (rainy season) in 2014. The total sampling effort was 960 HP light traps and eight Shannon traps. Trypanosomatids were detected in Phlebotominae females through the amplification of the SSU rDNA region, and the positive samples were used in ITS1-PCR. Trypanosomatid species were identified using sequencing. Findings: a total of 1,527 sand flies representing 30 species were captured in which 949 (28 spp.) and 578 (22 spp.) were registered in July and November, respectively. In July, more specimens were captured in the gallery forests than in the HUs, and Nyssomyia whitmani was particularly frequent. In November, most of the specimens were found in the HUs, and again, Ny. whitmani was the predominant species. Lutzomyia longipalpis was commonly found in domestic areas, while Bichromomyia flaviscutellata was most frequent in gallery forests. Molecular analysis of 154 pools of females (752 specimens) identified Leishmania amazonensis, L. infantum, and Crithidia fasciculata in Ny. whitmani, as well as L. amazonensis in Lu. longipalpis, Trypanosoma sp. and L. amazonensis in Pintomyia christenseni, and L. amazonensis in both Psathyromyia hermanlenti and Evandromyia walkeri. Main conclusions: these results show the importance of gallery forests in maintaining Phlebotominae populations in the dry month, as well as their frequent occurrence in household units in the rainy month. This is the first study to identify Leishmania, Trypanosoma, and Crithidia species in Phlebotominae collected in Palmas, Tocantins, Brazil

Expanding the knowledge about Leishmania species in wild mammals and dogs in the Brazilian savannah

Background: Wild, synanthropic and domestic mammals act as hosts and/or reservoirs of several Leishmania spp. Studies on possible reservoirs of Leishmania in different areas are fundamental to understand host-parasite interactions and develop strategies for the surveillance and control of leishmaniasis. In the present study, we evaluated the Leishmania spp. occurrence in mammals in two conservation units and their surroundings in Brasília, Federal District (FD), Brazil. Methods: Small mammals were captured in Brasília National Park (BNP) and Contagem Biological Reserve (CBR) and dogs were sampled in residential areas in their vicinity. Skin and blood samples were evaluated by PCR using different molecular markers (D7 24Sα rRNA and rDNA ITS1). Leishmania species were identified by sequencing of PCR products. Dog blood samples were subjected to the rapid immunochromatographic test (DPP) for detection of anti-Leishmania infantum antibodies. Results: 179 wild mammals were studied and 20.1% had Leishmania DNA successfully detected in at least one sample. Six mammal species were considered infected: Clyomys laticeps, Necromys lasiurus, Nectomys rattus, Rhipidomys macrurus, Didelphis albiventris and Gracilinanus agilis. No significant difference, comparing the proportion of individuals with Leishmania spp., was observed between the sampled areas and wild mammal species. Most of the positive samples were collected from the rodent N. lasiurus, infected by L. amazonensis or L. braziliensis. Moreover, infections by Trypanosoma spp. were detected in N. lasiurus and G. agilis. All 19 dog samples were positive by DPP; however, only three (15.8%) were confirmed by PCR assays. DNA sequences of ITS1 dog amplicons showed 100% identity with L. infantum sequence. Conclusions: The results suggest the participation of six species of wild mammals in the enzootic transmission of Leishmania spp. in FD. This is the first report of L. amazonensis in N. lasiurus

Detecção parasitológica e molecular de tripanossomatídeos em triatomíneos sinantrópicos e primatas neotropicais no Brasil central

O conhecimento atualizado da distribuição e infecção natural de triatomíneos sinantrópicos é fundamental para vigilância e controle da doença de Chagas. No Brasil, a detecção de Trypanosoma cruzi em triatomíneos é realizada por microscopia óptica (MO) do conteúdo intestinal, que pode apresentar diversas limitações quanto à sua sensibilidade e especificidade. Objetivos: Analisar a ocorrência de triatomíneos e suas taxas de infecção natural por T. cruzi e outros tripanossomatídeos no estado de Goiás (GO) e Distrito Federal (DF), estimar a sensibilidade da MO para detecção de T. cruzi em triatomíneos e analisar a transmissão de T. cruzi em ambientes onde colônias de triatomíneos infectados forem detectadas. Métodos: Os espécimes (adultos e ninfas) capturados no intra e peridomicílio e resultados dos exames parasitológicos a fresco e lâminas coradas foram obtidos por meio do LACEN/SES/GO e DIVAL/DF. O DNA foi extraído de amostras do intestino para realização das PCRs (cPCR e qPCR) utilizando quatro marcadores moleculares (TCZ, kDNA, rDNA 18S e rDNA24sα). Também, foi avaliada a infecção por T. cruzi em colônia de P. megistus (nestedcPCR) e em amostras sanguíneas provenientes de primatas neotropicais não-humanos (nestedqPCR) encontrados no Zoológico de Brasília (ZooB). Resultados: Foram analisados 2715 triatomíneos provenientes de 12/30 regiões administrativas do DF e 95/246 municípios de GO. Houve predomínio de T. sordida em GO e no DF P. megistus foi mais frequente, com taxas de infecção por flagelados similares a T. cruzi de 4,6% e 1,6%, respectivamente. A MO revelou 144/841 triatomíneos positivos para tripanossomatídeos, resultando em uma taxa de infecção de 17,1%. A qPCR, específica para T. cruzi, revelou 347 positivos (41,2%). A sensibilidade da MO para T. cruzi, tendo como referência a TCZ qPCR, foi estimada em 23,6% e a da rDNA24sα cPCR foi estimada em 58,5%. Blastocrithidiatriatomae e T. rangeli foram detectadas nos triatomíneos assim como infecções mistas por T. cruzi e B. triatomae. As taxas de infecção por T. cruzi nas espécies de triatomíneos variaram de 19 a 67% sendo maiores para T. pseudomaculata e em triatomíneos vivos e frescos. O sequenciamento revelou TcI em P. megistus e T. sordida e TcII em P. megistus e T. pseudomaculata. No ZooBT. cruzi foi encontrado em P. megistus (44/50) e em primatas (17/26) de seis gêneros e oito espécies, sendo que um Mico chrysoleucus e um Saguinusniger apresentaram alta parasitemia. Discussão e Conclusão:Os resultados mostram uma baixa sensibilidade da MO para a detecção de tripanosomatídeos em triatomíneos e infecções por pelo menos três espécies de tripanossomatídeos, o que reforça a necessidade de métodos de alta especificidade para o desenvolvimento de estratégias de vigilância adequadas dos vetores da doença de Chagas. O método de TCZ qPCR pode ser considerado um padrão referência para detecção de T. cruziem triatomíneos. ________________________________________________________________________________________________ ABSTRACTThe current knowledge of the distribution and natural infection of synanthropictriatomines is essential for surveillance and control of Chagas disease. In Brazil, optical microscopy (OM) has been used to detect Trypanosoma cruzi in triatomines, but this technique can present several limitations in terms of sensitivity and specificity. Objectives: Analyze the occurrence of triatomines and their natural infection rates for Trypanosoma cruzi in state of Goiás (GO) and the Federal District (DF),estimate the sensitivity of OM to detect T. cruzi in triatomines, and analyze T. cruzi transmission foci in environments where infected triatomine colonies were detected. Methods: The specimens (adults and nymphs) captured in the intra and peridomicile and results of parasitological fresh and stained slides were obtained from LACEN/SES/GO and DIVAL/DF. DNA was extracted from the intestine samples for the PCRs (cPCR and qPCR) using four molecular markers (TCZ, kDNA, 18S and rDNA24sα). Also, T. cruzi infections were assessed in a Panstrongylusmegistuscolony and from blood samples of nonhuman primates found in the Brasilia Zoo (ZooB). Results:2715 triatomines were analyzed from 12/30 administrative regions of the DF and 95/246 municipalities of GO. In GO, T. sordida predominate while in the DF P. megistus was more frequent, with infection rates by flagellates similar to T. cruzi of 4.6% and 1.6%, respectively. OM revealed 144/841 trypanosomatid-positive triatomines, resulting in a 17.1% infection rate. The T. cruzi TCZ qPCR, showed 347 positive (41.2%). The sensitivity of T. cruzi-OM with reference to TCZ qPCR was estimated at 23.6% and rDNA24sα cPCR was estimated at 58.5%. Triatomines were infected by Blastocrithidiatriatomae and T. rangeli. However, mixed infections with T. cruzi and B. triatomae were found. Infection rates by T. cruzi in triatomine species ranged 19-67% and were higher for T. pseudomaculata and alive and fresh triatomines. The sequencing of some samples confirmed the identification of B. triatomae and revealed TcI in P. megistus and T. sordida, and TcII in P. megistus and T. pseudomaculata. In ZooB, T. cruzi was found in 44/50 P. megistus and 17/26 primates (six genera and eight species); one Micochrysoleucus and one Saguinusniger showed high parasitaemia. Discussion and Conclusion: The results show a low sensitivity of OM for trypanosomatids detection in triatomines and infections for at least three trypanosomatid species, which reinforces the need for highly specific methods for the development of appropriate surveillance strategies of the vectors of Chagas disease. It also suggests that the TCZ qPCR method could be considered as a reference standard for detection of T. cruziin triatomines

Identificação fenotípica de Dientamoeba fragilis (Jepps & Dobell, 1918) e Blastocystis hominis (Brumpt, 1912) em pacientes atendidos no ambulatório do Hospital Universitário de Brasília: caracterização molecular preliminar de isolados diagnosticados

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, 2010.Dientamoeba fragilis e Blastocystis hominis são parasitos do trato gastrointestinal de humanos que podem estar associados a infecções intestinais e diarréias, sendo, porém, negligenciados nos testes de diagnóstico hospitalar. 158 amostras fecais foram coletadas de pacientes atendidos no ambulatório do Hospital Universitário de Brasília (HUB), durante o período de maio de 2008 a janeiro de 2009, com objetivo de identificar os protozoários parasitos com ênfases em D. fragilis e B. hominis. As amostras coletadas foram fixadas diretamente em SAF (acetato de sódio, ácido acético e formol) para a realização de exames coprológicos, auxiliados com técnicas de concentração, de preparação de lâminas permanentes coradas com Hematoxilina Férrica e biometria de trofozoítos de D. fragilis e cistos e trofozoítos de B. hominis. Estas amostras foram coletadas e sedimentadas frescas para realizar a amplificação do DNA de D. fragilis e B. hominis por intermédio da PCR (Polymerase Chain Reaction). Das 158 amostras fecais coletadas, 69% são pacientes do sexo feminino e 31% são pacientes do sexo masculino. Destas, 56,3% das amostras fecais (n = 89) foram positivas para algum parasito intestinal, sendo que 28 amostras foram positivas para D. fragilis e 44 para B. hominis. Houve poliparasitismo em 46 amostras sendo que ocorreu associação D. fragilis e B. hominis em 8 amostras. Com base na ferramenta molecular, a PCR foi otimizada com sucesso somente para B. hominis. Estudos moleculares confirmaram a presença do B. hominis em 6 de 8 amostras positivas em microscopia de luz e em 2 dos 5 amostras negativas. Esses resultados confirmam uma elevada frequência destes protozoários intestinais na população ambulatorial selecionada e podem ser justificados pelos métodos de diagnósticos utilizados que raramente são seguidos em laboratórios de diagnóstico clínico. _______________________________________________________________________________ ABSTRACTDientamoeba fragilis and Blastocystis hominis are parasites of the gastrointestinal tract of humans that may be associated with intestinal infections and diarrhea, but are neglected in hospital diagnostic tests. 158 fecal samples were collected from patients attending the ambulatory service of the University of Brasilia (HUB) teaching hospital in Brasilia, Federal District, Brazil. During the period May 2008 to January 2009 aiming to identify the protozoan parasites with emphasis on D. fragilis and B. hominis. Samples were collected directly into sodium acetate–acetic acid–formalin (SAF) and also as unfixed specimens, during a period of may 2008 and january 2009. Stool tests, helped with concentration techniques, preparation of permanent slides stained with hematoxylin and biometry of trophozoites of D. fragilis and cysts and trophozoites of B. hominis, were performed for phenotypic characterization. The PCR (Polymerase Chain Reaction) was used with specific primers and optimized successfully only for B. hominis. Of the 158 fecal samples collected, 69% were female and 31% male. Of these, 56.3% of samples (n = 89) were positive for some intestinal parasite, and 28 samples were positive for D. fragilis and 44 for B. hominis. From 46 individuals an association of D. fragilis and B. hominis were identified in 8 patients. Molecular studies confirmed the presence of B. hominis in 6 of 8 positive samples in light microscopy and in 2 of 5 negative samples. These results confirm a high frequency of these protozoans in outpatient population selected and can be justified by the diagnostic methods used which are rarely followed in clinical diagnostic laboratories

Molecular detection of Trypanosoma sp. and Blastocrithidia sp. (Trypanosomatidae) in phlebotomine sand flies (Psychodidae) in the Federal District of Brazil

Abstract: INTRODUCTION : This study describes the occurrence of trypanosomatids in phlebotomines in Brasília, Brazil. METHODS : Two hundred and ten females of 13 sand fly species were analyzed by polymerase chain reaction (PCR) using different molecular markers (D7 24Sα rRNA, kDNA, and ITS1) and sequencing. RESULTS : PCR revealed trypanosomatid-positive samples from Nyssomyia whitmani and Evandromyia evandroi, which were negative by kDNA and ITS1 Leishmania-specific PCRs. DNA sequence analysis of D7 24Sα rRNA amplicons indicated the occurrence of Blastocrithidia sp. and Trypanosoma sp. in Nyssomyia whitmani and Evandromyia evandroi, respectively. CONCLUSIONS : Two trypanosomatid species other than Leishmania sp. were found to circulate in sand flies in Central Brazil

Synanthropic triatomines as potential vectors of Trypanosoma cruzi in Central Brazil

Abstract INTRODUCTION: Chagas disease surveillance requires current knowledge on synanthropic triatomines. We analyzed the occurrence and Trypanosoma cruzi infection rates of triatomine bugs in central Brazil, during 2012-2014. METHODS: Triatomines were collected inside or around houses, and T. cruzi infection was determined by optical microscopy and conventional/quantitative polymerase chain reaction. RESULTS: Of the 2706 triatomines collected, Triatoma sordida was the most frequent species in Goiás State, whereas Panstrongylus megistus predominated in the Federal District. Parasites identified were T. cruzi, T. rangeli, and Blastocrithidia sp. CONCLUSIONS: P. megistus and T. sordida sustained the risk of T. cruzi transmission to humans in central Brazil