title: Trypanosoma cruzi immune response modulation decreases microbiota in Rhodnius prolixus gut and is crucial for parasite survival and development.
abstract: Trypanosoma cruzi in order to complete its development in the digestive tract of Rhodnius prolixus needs to overcome the immune reactions and microbiota trypanolytic activity of the gut. We demonstrate that in R. prolixus following infection with epimastigotes of Trypanosoma cruzi clone Dm28c and, in comparison with uninfected control insects, the midgut contained (i) fewer bacteria, (ii) higher parasite numbers, and (iii) reduced nitrite and nitrate production and increased phenoloxidase and antibacterial activities. In addition, in insects pre-treated with antibiotic and then infected with Dm28c, there were also reduced bacteria numbers and a higher parasite load compared with insects solely infected with parasites. Furthermore, and in contrast to insects infected with Dm28c, infection with T. cruzi Y strain resulted in a slight decreased numbers of gut bacteria but not sufficient to mediate a successful parasite infection. We conclude that infection of R. prolixus with the T. cruzi Dm28c clone modifies the host gut immune responses to decrease the microbiota population and these changes are crucial for the parasite development in the insect gut.
authors.affiliation: Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Rio de Janeiro, Brazil. danicastro@ioc.fiocruz.br
authors.forename: Daniele P
authors.initials: DP
authors.lastname: Castro
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Moraes
authors.forename: Marcelo S
authors.initials: MS
authors.lastname: Gonzalez
authors.forename: Norman A
authors.initials: NA
authors.lastname: Ratcliffe
authors.forename: Patrícia
authors.initials: P
authors.lastname: Azambuja
authors.forename: Eloi S
authors.initials: ES
authors.lastname: Garcia
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D014355:Chagas Disease / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D056724:Immunity, Humoral / Q000187:drug effects / Q000276:immunology; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000187:drug effects / Q000276:immunology* / Q000469:parasitology*; D054892:Metagenome / Q000187:drug effects / Q000276:immunology*; D014442:Monophenol Monooxygenase / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D012239:Rhodnius / Q000187:drug effects / Q000378:metabolism / Q000382:microbiology* / Q000469:parasitology*; D013045:Species Specificity; D016019:Survival Analysis; D014349:Trypanosoma cruzi / Q000254:growth & development* / Q000472:pathogenicity
chemical_list: D000900:Anti-Bacterial Agents; D009566:Nitrates; D009573:Nitrites; D014442:Monophenol Monooxygenase