Browsing by Author "Quiroga, Nicol"

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    Blood-Meal Sources and Trypanosoma cruzi Infection in Coastal and Insular Triatomine Bugs from the Atacama Desert of Chile
    (2022-04-08) Quiroga, Nicol; Correa, Juana P.; Campos-Soto, Ricardo; San Juan, Esteban; Araya-Donoso, Raúl; Díaz-Campusano, Gabriel; González, Christian R.; Botto-Mahan, Carezza
    Mepraia parapatrica is one of the lesser known and less abundant sylvatic triatomine species naturally infected by the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. M. parapatrica lives in sympatry with T. cruzi-infected rodents, but only birds, reptiles, and marine mammals have been reported as blood-meal sources of this vector species by serology. The distribution range of this kissing bug overlaps with fishers’ settlements and tourist areas, and therefore the study of the blood-meal sources of this triatomine species is relevant. Here, we determined the blood-meal sources of M. parapatrica by NGS or standard sequencing from a coastal mainland area and an island in northern Chile, and T. cruzi infection by real-time PCR. The blood-meals of. M parapatrica included 61.3% reptiles, 35.5% mammals (including humans) and 3.2% birds. Feeding on reptiles was more frequent on the mainland, while on the island feeding on mammals was more frequent. The presence of T. cruzi-infected triatomine bugs and humans as part of the diet of M. parapatrica in both areas represents an epidemiological threat and potential risk to the human population visiting or established in these areas. Currently there are no tools to control wild triatomines; these results highlight the potential risk of inhabiting these areas and the necessity of developing information campaigns for the community and surveillance actions.
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    DETECCIÓN DE Trypanosoma cruzi EN LAGARTOS Microlophus atacamensis DE UNA ISLA COSTERA DEL DESIERTO DE ATACAMA
    (2024-06) Borcosque. Josefa; Campos-Soto, Ricardo; Quiroga, Nicol; Cianferoni, Franco; Díaz-Campusano, Gabriel; Marcos, José Luis; Botto-Mahan, Carezza; Torres-Pérez, Fernando
    La enfermedad de Chagas es producida por el parásito Trypanosoma cruzi, el cual está presente en vinchucas y sangre/tejidos de mamíferos, considerándose las aves refractarias a la infección. Mepraia es un género de vinchuca responsable de transmitir T. cruzi en el ciclo silvestre de Chile. Se ha evidenciado la presencia de ejemplares de Mepraia infectados con T. cruzi en la Isla Santa María (Región de Antofagasta). En esta isla no se ha registrado presencia de micromamíferos y los vertebrados más comunes son el lagarto Microlophus atacamensis, jotes y aves marinas. En las vinchucas de esta isla se ha reportado un alto porcentaje de infección e incluso infecciones mixtas, con más de un DTU de T. cruzi, lo que está comúnmente asociado a ecosistemas con una alta biodiversidad y abundancia de mamíferos. Esto contrasta con la nula captura de micromamíferos reportada en esta isla. Considerando que recientemente se ha publicado que los reptiles también son hospederos de T. cruzi, se puede inferir que los lagartos M. atacamensis podrían estar manteniendo la infección de T. cruzi en la Isla Santa María. El objetivo de este estudio es determinar si individuos de M. atacamensis de la Isla Santa María son hospederos de T. cruzi. En 33 muestras de sangre de M. atacamensis se detectó T. cruzi mediante la amplificación de un segmento de ADN kinetoplastídico por PCR convencional y un segmento nuclear de T. cruzi por real time PCR. Se determinó un 60.6% de infección mediante PCR convencional, mientras que por real time PCR un 51.1%. Se concluye que M. atacamensis es un hospedero de T. cruzi, sugiriendo que podría ser un reservorio clave que está mantenido la infección en la Isla Santa María. Estos resultados contribuyen al entendimiento del ciclo de vida que desarrolla T. cruzi en esta particular isla del extremo norte del desierto de Atacama.
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    Humans as blood-feeding sources in sylvatic triatomines of Chile unveiled by next-generation sequencing
    (2023-07-06) San Juan, Esteban; Araya‑Donoso, Raúl; Sierra‑Rosales, Catalina; Correa, Juana P; Quiroga, Nicol; Campos‑Soto, Ricardo; Solari, Aldo; Llewellyn, Martin; Bacigalupo, Antonella; Botto‑Mahan, Carezza
    Background Triatomines are blood-sucking insects capable of transmitting Trypanosoma cruzi, the parasite that causes Chagas disease in humans. Vectorial transmission entails an infected triatomine feeding on a vertebrate host, release of triatomine infective dejections, and host infection by the entry of parasites through mucous membranes, skin abrasions, or the biting site; therefore, transmission to humans is related to the triatomine–human contact. In this cross-sectional study, we evaluated whether humans were detected in the diet of three sylvatic triatomine species (Mepraia parapatrica, Mepraia spinolai, and Triatoma infestans) present in the semiarid–Mediterranean ecosystem of Chile. Methods We used triatomines collected from 32 sites across 1100 km, with an overall T. cruzi infection frequency of 47.1% (N=4287 total specimens) by conventional PCR or qPCR. First, we amplifed the vertebrate cytochrome b gene (cytb) from all DNA samples obtained from triatomine intestinal contents. Then, we sequenced cytb-positive PCR products in pools of 10–20 triatomines each, grouped by site. The fltered sequences were grouped into amplicon sequence variants (ASVs) with a minimum abundance of 100 reads. ASVs were identifed by selecting the best BLASTn match against the NCBI nucleotide database. Results Overall, 16 mammal (including human), 14 bird, and seven reptile species were identifed in the diet of syl‑ vatic triatomines. Humans were part of the diet of all analyzed triatomine species, and it was detected in 19 sites representing 12.19% of the sequences. Conclusions Sylvatic triatomine species from Chile feed on a variety of vertebrate species; many of them are detected here for the frst time in their diet. Our results highlight that the sylvatic triatomine–human contact is noteworthy. Education must be enforced for local inhabitants, workers, and tourists arriving in endemic areas to avoid or minimize the risk of exposure to Chagas disease vectors.
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    Lizards as Silent Hosts of Trypanosoma cruzi
    (2022-06) Botto-Mahan, Carezza; Correa, Juana P.; Araya-Donoso, Raúl; Farías, Francisca; San Juan, Esteban; Quiroga, Nicol; Campos-Soto, Ricardo; Reyes-Olivares, Claudio; González-Acuña, Daniel
    We assessed 4 lizard species in Chile for Trypanosoma cruzi, the causative agent of Chagas disease, and 1 species for its ability to transmit the protozoan to uninfected kissing bugs. All lizard species were infected, and the tested species was capable of transmitting the protozoan, highlighting their role as T. cruzi reservoirs.
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    Trypanosoma cruzi DNA in Desmodus rotundus (common vampire bat) and Histiotus montanus (small big-eared brown bat) from Chile
    (2021-10-21) Quiroga, Nicol; Campos Soto, Ricardo; Yánez Meza, Andrea; Rodríguez San Pedro, Annia; Allendes, Juan L.; Bacigalupo, Antonella; Botto-Mahan, Carezza; Correa, Juana P.
    The protozoan Trypanosoma cruzi, the causative agent of Chagas disease, is transmitted by infected feces or consumption of blood-sucking triatomine insects to several mammalian orders including Chiroptera. In Chile, the distribution of several insectivorous and one hematophagous bat species overlaps with those of triatomine vectors, but the T. cruzi infection status of local chiropterans is unknown. In 2018, we live-captured bats from two protected areas in Chile to collect plagiopatagium tissue, feces and perianal swab samples, in search for T. cruzi-DNA by real time PCR assays using species-specific primers. In Pan de Azúcar island (~26◦S), we examined a roost of Desmodus rotundus (common vampire bat) and sampled tissue from 17 individuals, detecting T. cruzi-DNA in five of them. In Las Chinchillas National Reserve (~31◦S), we examined two roosts of Histiotus montanus (small big-eared brown bat), collecting feces or perianal swab samples from eight individuals, detecting T. cruzi-DNA in four of them. This is the first report of T. cruzi-DNA evidence in bat species from Chile. Both vector-borne and oral transmission are potential infection routes that can explain our results. Further investi gation is needed for a better understanding of the role of bats in the T. cruzi transmission cycle.