Cultivation-Independent Methods Reveal Differences among Bacterial Gut Microbiota in Triatomine Vectors of Chagas Disease

Chagas disease is one of the most important endemic diseases of South and Central America. Its causative agent is the protozoan Trypanosoma cruzi, which is transmitted to humans by blood-feeding insects known as triatomine bugs. These vectors mainly belong to Rhodnius, Triatoma and Panstrongylus genera of Reduviidae. The bacterial communities in the guts of these vectors may have important effects on the biology of T. cruzi. For this reason, we analyzed the bacterial diversity hosted in the gut of different species of triatomines using cultivation-independent methods. Among Rhodnius sp., we observed similar bacterial communities from specimens obtained from insectaries or sylvatic conditions. Endosymbionts of the Arsenophonus genus were preferentially associated with insects of the Panstrongylus and Triatoma genera, whereas the bacterial genus Serratia and Candidatus Rohrkolberia were typical of Rhodnius and Dipetalogaster, respectively. The diversity of the microbiota tended to be the largest in the Triatoma genus, with species of both Arsenophonus and Serratia being detected in T. infestans

Trypanosoma cruzi TcSMUG L-surface Mucins Promote Development and Infectivity in the Triatomine Vector Rhodnius prolixus

Made available in DSpace on 2015-08-19T13:49:31Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) eloi_garcia_etal_IOC_2013.pdf: 6467561 bytes, checksum: 3d08464f54865b8fee87e5456fed719c (MD5) Previous issue date: 2013Universidade Federal Fluminense. Instituto de Biologia. Departamento de Biologia Geral. Laboratório de Biologia de Insetos. Niterói, RJ, Brasil / Instituto Nacional de Entomologia Molecular (INCT-EM, CNPq). Brasil.Universidade Federal Fluminense. Instituto de Biologia. Departamento de Biologia Geral. Laboratório de Biologia de Insetos. Niterói, RJ, Brasil.Instituto Nacional de Entomologia Molecular (INCT-EM, CNPq). Brasil / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Universidade Estadual do Norte Fluminense - Horto. Centro de Biocieˆncias e Biotecnologia. Laborato´ rio de Biologia Celular e Tecidual. Campos dos Goytacases, RJ, Brasil.Universidade Federal Fluminense. Instituto de Biologia. Departamento de Biologia Geral. Laboratório de Biologia de Insetos. Niterói, RJ, Brasil / Instituto Nacional de Entomologia Molecular (INCT-EM, CNPq). Brasil.Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Instituto de Investigaciones Biotecnológicas ‘‘Dr Rodolfo Ugalde’’. Campus UNSAM. Buenos Aires, Argentina.Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Instituto de Investigaciones Biotecnológicas ‘‘Dr Rodolfo Ugalde’’. Campus UNSAM. Buenos Aires, Argentina.nstituto Nacional de Entomologia Molecular (INCT-EM, CNPq). Brasil / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Instituto de Investigaciones Biotecnológicas ‘‘Dr Rodolfo Ugalde’’. Campus UNSAM. Buenos Aires, Argentina.Background: TcSMUG L products were recently identified as novel mucin-type glycoconjugates restricted to the surface of insect-dwelling epimastigote forms of Trypanosoma cruzi, the etiological agent of Chagas disease. The remarkable conservation of their predicted mature N-terminal region, which is exposed to the extracellular milieu, suggests that TcSMUG L products may be involved in structural and/or functional aspects of the interaction with the insect vector. Methodology and Principal Findings: Here, we investigated the putative roles of TcSMUG L mucins in both in vivo development and ex vivo attachment of epimastigotes to the luminal surface of the digestive tract of Rhodnius prolixus. Our results indicate that the exogenous addition of TcSMUG L N-terminal peptide, but not control T. cruzi mucin peptides, to the infected bloodmeal inhibited the development of parasites in R. prolixus in a dose-dependent manner. Pre-incubation of insect midguts with the TcSMUG L peptide impaired the ex vivo attachment of epimastigotes to the luminal surface epithelium, likely by competing out TcSMUG L binding sites on the luminal surface of the posterior midgut, as revealed by fluorescence microscopy. Conclusion and Significance: Together, these observations indicate that TcSMUG L mucins are a determinant of both adhesion of T. cruzto the posterior midgut epithelial cells of the triatomine, and the infection of the insect vector, R. prolixus