Seropositividad a Chlamydophila psittaci en cotorras argentinas (Myiopsitta monachus) invasoras de la ciudad de Santiago de Chile

Introducción: Chlamydophila psittaci es una bacteria zoonótica e intracelular estricta, que provoca la psitacosis humana y su principal hospedero son las aves psitácidas. La cotorra argentina es un ave psitácida nativa de Sudamérica y actualmente considerada una especie invasora en 19 países, incluyendo Chile. Objetivo: Determinar positividad contra C. psittaci en muestras de suero y torulados de cotorras argentinas de vida libre capturadas en la Región Metropolitana de Chile. Métodos: Se analizaron 95 muestras de suero de pichones e individuos adultos de cotorras argentinas, a través de una prueba de ELISA indirecto utilizando un kit comercial. Posteriormente, se analizaron 40 tórulas nasotraqueales y cloacales de individuos adultos a través de una RPC en tiempo real específica para C. psittaci. Resultados: Se detectaron anticuerpos en muestras de suero de cinco individuos adultos de cotorras argentinas (n = 68), mientras que ninguno de los pichones analizados fue seropositivo (n = 27). Todas las muestras analizadas a través de RPC en tiempo real fueron negativas. Conclusión: Estos resultados demuestran por primera vez en Chile la exposición a C. psittaci en cotorras argentinas de vida libre, lo cual puede representar un riesgo importante para la transmisión de este patógeno a poblaciones humanas y animales.

Background: Chlamydophila psittaci is a zoonotic obligate intracellular bacterium that causes the human psittacosis, and its main host are psittacine birds. The monk parakeet is a psittacine bird native to South America, currently being considered an invasive species in 19 countries, including Chile. Aim: To determine positivity to C. psittaci in serum samples and swabs from free-ranging monk parakeets captured in the Metropolitan Region of Chile. Methods: Ninety-five serum samples from nestling chicks and adult monk parakeets were tested using an indirect ELISA test kit. Cloacal and nasotracheal swabs from 40 adult parakeets were further analyzed by C. psittaci-specific real-time PCR. Results: We found antibody titers in sera of five adult monk parakeets (n = 68) while none of the nestlings were seropositive (n = 27). All samples tested with real-time PCR were negative. Conclusions: Our results demónstrate for the first time in Chile the exposure to C. psittaci in free-ranging monk parakeets which may represent a significant risk of pathogen transmission to human and animal populations.

Cryptosporidium spp. and Giardia spp. in Free-Ranging Introduced Monk Parakeets from Santiago, Chile.

Monk Parakeets (Myiopsitta monachus) are medium-sized parrots that due to international pet trade currently exist as invasive species in 19 countries globally. Such is the case of Chile, where Monk Parakeets have thrived in the city of Santiago. Cryptosporidium spp. and Giardia spp. are worldwide distributed gastrointestinal parasites whose potential hosts include birds and humans. The present study sought to determine the presence of these pathogens in Monk Parakeets from Santiago. During the austral summers of 2017 and 2018, 207 Monk Parakeet nestlings were captured, and fecal samples were studied via microscopical analyses. Environmental data related to the trees in which the nestlings were captured were analyzed to establish the existence of infection clusters. Associations between spatial clusters, environmental variables, and the presence or absence of these pathogens were explored. In total, 33 samples were positive to the presence of one or both protozoa. Of the 33, Cryptosporidium spp. oocysts were detected in 10 nestlings (30%) while Giardia spp. cysts were detected in 25 (76%). Two nestlings presented poly-parasitism (6%). Statistical analyses established pruned trees as a potential protective factor against infection with these parasites. The present study corresponds to the second report of Cryptosporidium spp. in Monk Parakeets in Chile and the first worldwide report of Giardia spp. in these birds, emphasizing Monk Parakeet's potential role as a reservoir and pathogen disseminator, especially in urban environments.

First record of Ornithonyssus bursa (Berlese, 1888) (Mesostigmata: Macronyssidae) parasitizing invasive monk parakeets in Santiago, Chile.

Myiopsitta monachus is an invasive psittacine with wide distribution due to the pet trade. Its large communal nests and synanthropic nature contribute to its successful colonization of cities, from where it seems to be expanding in range and numbers. This is relevant with regard to pathogens that invasive species may harbor, especially when host populations thrive. We aimed to identify an abundant mite found in invasive monk parakeet chicks that had been collected in Santiago during 2017 and 2018. Through morphological and molecular identification of the 18S ribosomal RNA gene, we confirmed the presence of Ornithonyssus bursa. This was the first report of this mite in Chile. This mite is common in native and invasive monk parakeet populations and may affect other birds, including domestic fowl. Further, this mite bites people and can be a potential vector of pathogens such as bacteria or viruses. We conclude that this parasite was likely introduced with the parakeet and discuss possible ecological, health and economic consequences of this new potential pest.

First record of Ornithonyssus bursa (Berlese, 1888) (Mesostigmata: Macronyssidae) parasitizing invasive monk parakeets in Santiago, Chile / Primeiro registro de Ornithonyssus bursa (Berlese, 1888) (Mesostigmata: Macronyssidae) parasitando caturritas invasoras em Santiago, Chile

Abstract Myiopsitta monachus is an invasive psittacine with wide distribution due to the pet trade. Its large communal nests and synanthropic nature contribute to its successful colonization of cities, from where it seems to be expanding in range and numbers. This is relevant with regard to pathogens that invasive species may harbor, especially when host populations thrive. We aimed to identify an abundant mite found in invasive monk parakeet chicks that had been collected in Santiago during 2017 and 2018. Through morphological and molecular identification of the 18S ribosomal RNA gene, we confirmed the presence of Ornithonyssus bursa. This was the first report of this mite in Chile. This mite is common in native and invasive monk parakeet populations and may affect other birds, including domestic fowl. Further, this mite bites people and can be a potential vector of pathogens such as bacteria or viruses. We conclude that this parasite was likely introduced with the parakeet and discuss possible ecological, health and economic consequences of this new potential pest.

Resumo Myiopsitta monachus é um psitacídeo invasor amplamente distribuído devido ao tráfico de animais selvagens. Os grandes ninhos comunitários construídos e sua condição de espécies sinantrópicas contribuem para a colonização bem-sucedida das cidades, onde parece estar expandindo sua distribuição e número de indivíduos. Isso é relevante, quando se trata de patógenos que os invasores podem abrigar, especialmente quando as populações hospedeiras prosperam. O objetivo deste trabalho foi identificar um ácaro abundante, encontrado em filhotes de periquitos-monge introduzidos em Santiago, Chile, coletados durante 2017 e 2018. Por meio da identificação morfológica e molecular do gene do RNA ribossômico 18S, foi confirmada a presença de Ornithonyssus bursa, sendo o primeiro registro para o Chile. Esse ácaro é comum em populações nativas e introduzidas de periquitos-monge e pode afetar outras aves, incluindo aves domésticas. Além disso, esse ácaro pode picar pessoas e pode ser um potencial vetor de patógenos, como bactérias ou vírus. Conclui-se que esse parasita provavelmente foi introduzido com o periquito e foram discutidas as possíveis consequências ecológicas de saúde e econômicas dessa nova praga em potencial.

Organs infected with Trypanosoma cruzi and DTU identification in the naturally infected rodent Octodon degus.

Chagas disease is a public health problem in America. Its parasite, Trypanosoma cruzi, presents different discrete typing units (DTUs), colonizes organs of mammalian hosts in chronic infections, and presents tropism for particular organs in experimental infections. We evaluated T. cruzi tropism towards organs on the naturally infected rodent Octodon degus, identifying the parasites' DTUs, by means of conventional PCR and hybridization. Almost all the analyzed organs presented T. cruzi. More than 42% of the tested oesophagus, skin, skeletal muscle, brain and intestine showed T. cruzi DNA. Other nine types of organs were infected in over 15%. These results suggest that there is some tropism by T. cruzi in chronically infected O. degus. DTU TcV was present in 92.5% of infected organs with identified DTUs; this DTU is frequently reported in human infections in the Southern Cone of South America. Few organs showed mixed DTU infections. This is one of the few reports on the outcome of chronic natural T. cruzi-infection in wild mammal hosts exposed to naturally infected vectors.

Lizards and rabbits may increase Chagas infection risk in the Mediterranean-type ecosystem of South America.

Studies of host-parasite relationships largely benefit from adopting a multifactorial approach, including the complexity of multi-host systems and habitat features in their analyses. Some host species concentrate most infection and contribute disproportionately to parasite and vector population maintenance, and habitat feature variation creates important heterogeneity in host composition, influencing infection risk and the fate of disease dynamics. Here, we examine how the availability of specific groups of hosts and habitat features relate to vector abundance and infection risk in 18 vector populations along the Mediterranean-type ecosystem of South America, where the kissing bug Mepraia spinolai is the main wild vector of the parasite Trypanosoma cruzi, the etiological agent of Chagas disease. For each population, data on vectors, vertebrate host availability, vegetation, precipitation, and temperature were collected and analyzed. Vector abundance was positively related to temperature, total vegetation, and European rabbit availability. Infection risk was positively related to temperature, bromeliad cover, and reptile availability; and negatively to the total domestic mammal availability. The invasive rabbit is suggested as a key species involved in the vector population maintenance. Interestingly, lizard species -a group completely neglected as a potential reservoir-, temperature, and bromeliads were relevant factors accounting for infection risk variation across populations.

Interactions between Invasive Monk Parakeets (Myiopsitta monachus) and Other Bird Species during Nesting Seasons in Santiago, Chile.

The monk parakeet (Myiopsitta monachus) is considered to be one of the most invasive bird species because its unique ability among parrots to build their own communal nests. Currently, they are considered an invasive species in 19 countries and a pest-even in their native distribution-because of economic losses derived from their impacts. During the reproductive seasons of 2017 and 2018, we registered interactions between invasive monk parakeets and resident bird species in Santiago, Chile. We observed agonistic and affiliative interactions, and further, we described monk parakeets' nest occupancy by nine bird species, two invasive and seven native. For this reason, we consider that the monk parakeet is an allogenic ecosystem engineer with the potential to shape distribution and richness of sympatric species in urban environments. Our results contribute to an assessment of the implications of the monk parakeet's ecological invasion to other synanthropic species, and raise concern of other potential impacts, such as pathogen transmission derived from these interactions.

Comparing vector competence of Mepraia gajardoi and Triatoma infestans by genotyping Trypanosoma cruzi discrete typing units present in naturally infected Octodon degus.

Chagas disease is a vector-borne disease caused by the parasite Trypanosoma cruzi, and transmitted by triatomine insects to several mammal species. In Chile, the wild triatomine species are the endemic Mepraia species, and the only domestic vector of Chagas disease is Triatoma infestans. The aim of this study was to determine the competence of M. gajardoi compared to T. infestans as a T. cruzi vector using the naturally infected rodent Octodon degus. M. gajardoi amplified T. cruzi present in all O. degus studied while T. infestans only in half of the infected rodents. Both triatomine species excrete metacyclic trypomastigotes and amplified the same three T. cruzi DTUs, however, M. gajardoi showed differences in their ability to amplify TcI. TcV and TcVI had the same probability to be amplified by both triatomine species. Both species amplified mixed infections, with TcI-TcVI as the most represented. This study reports the higher vector competence of M. gajardoi in comparison to T. infestans.

Within-host temporal fluctuations of Trypanosoma cruzi discrete typing units: the case of the wild reservoir rodent Octodon degus.

BACKGROUND: Chagas disease caused by Trypanosoma cruzi is considered a major public health problem in America. After an acute phase the disease changes to a chronic phase with very low parasitemia. The parasite presents high genetic variability with seven discrete typing units (DTUs): TcI-TcVI and Tc bat. The aim of this work is to evaluate fluctuation of parasitemia and T. cruzi DTUs in naturally infected Octodon degus. METHODS: After animal capture parasitemia was obtained by qPCR and later the animals were evaluated by three serial xenodiagnoses using two insect vector species, Mepraia spinolai and Triatoma infestans. The parasites amplified over time by insect xenodiagnosis were analyzed by conventional PCR and after that the infective T. cruzi were characterized by means of hybridization tests. RESULTS: The determination of O. degus parasitemia before serial xenodiagnosis by qPCR reveals a great heterogeneity from 1 to 812 parasite equivalents/ml in the blood stream. The T. cruzi DTU composition in 23 analyzed animals by xenodiagnosis oscillated from mixed infections with different DTUs to infections without DTU identification or vice versa, this is equivalent to 50% of the studied animals. Detection of triatomine infection and composition of T. cruzi DTUs was achieved more efficiently 40 days post-infection rather than after 80 or 120 days. CONCLUSION: Trypanosoma cruzi DTUs composition fluctuates over time in naturally infected O. degus. Three replicates of serial xenodiagnosis confirmed that living parasites have been studied. Our results allow us to confirm that M. spinolai and T. infestans are equally competent to maintain T. cruzi DTUs since similar results of infection were obtained after xenodiagnosis procedure.

Temporal variation in Trypanosoma cruzi lineages from the native rodent Octodon degus in semiarid Chile.

Chagas disease is a zoonosis caused by the protozoan parasite Trypanosoma cruzi and transmitted by triatomine insects to several mammalian species acting as reservoir hosts. In the present study, we assess T. cruzi-prevalence and DTU composition of the endemic rodent Octodon degus from a hyper-endemic area of Chagas disease in Chile. Parasite detection is performed by PCR assays on blood samples of individuals captured in the austral summers of 2010-2013. The infection level in rodents differed in the summers of these four years between 18% and 70%. Overall, infected O. degus showed similar T. cruzi-DTU composition (TcI, TcII, TcV and TcVI lineages) among years, corresponding to single and mixed infection, but the relative importance of each DTU changed among years. In 2013, we detected that only three out of the four T. cruzi-DTU found in O. degus were present in the endemic triatomine Mepria spinolai. We suggest that O. degus, an abundant long-lived rodent, is an important native reservoir of T. cruzi in the wild transmission cycle of Chagas disease and it is able to maintain all the T. cruzi-DTUs described in semiarid Chile.