Browsing by Author "Acosta Jamett, Gerardo"

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    A Third Amblyomma Species and the First Tick-Borne Rickettsia in Chile
    (OXFORD UNIV PRESS INC, 2012) Abarca, Katia; Lopez, Javier; Acosta Jamett, Gerardo; Lepe, Paulina; Soares, Joao Fabio; Labruna, Marcelo B.
    During November 2010, three ticks were collected from three dogs living in the rural area of Arica, northern Chile. Morphological analyses of the ticks in the laboratory revealed that they were most similar to Amblyomma maculatum Koch and Amblyomma triste Koch. However, because of unique metatarsal spurs, neither of the Chilean specimens could be assigned with certainty to A. maculatum or A. triste, based on external morphology. The mitochondrial 16S rRNA gene partial sequences obtained from two Chilean specimens were 99.5% identical to A. triste from Uruguay, and 99.0% identical to A. maculatum from the United States. Through phylogenetic analysis inferred from partial 16S rRNA sequences, the Chilean specimens were classified as A. triste. Molecular analyses also showed that one of the three Chilean ticks was infected by Candidatus 'Rickettsia andeanae'. These findings extend the geographical distribution of A. triste to Chile, where no tick-associated rickettsia had been reported previously.
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    Detection of Rickettsia andeanae in two regions of Chile
    (SOC CHILENA INFECTOLOGIA, 2013) Abarca, Katia; Lopez, Javier; Acosta Jamett, Gerardo; Martinez Valdebenito, Constanza
    Introduction: Candidatus 'Rickettsia andeanae' is recently recognized specie, with no attributed pathogenic role so far. It has been reported in Amblyomma ticks from Peru, USA and Argentina, and recently in Chile, in one specimen of Amblyomma triste from a rural locality in Arica. Objective: To determine the presence of rickettsial agents in ticks from domestic dogs from two Chilean regions. Methods: A transversal descriptive study in Coquimbo and Araucania regions, Consisted in households sampling in the cities of Coquimbo and Angol and nearby rural localities, in spring-summer 2011-2012. One clog per house was examined and ticks Were collected when present; after taxonomic identification, gltA and ompA genes were amplified and sequenced. Results: 462 dogs were examined, 255 had ticks (55%). In the cities just Rhipicephalus sanguineus was found; in rural localities also Amblyomma tigrinum. Obtained sequences in 12 specimens from A. tigrinum corresponded to Candidatus 'Rickettsia andeanae'. Conclusions: We documented the presence of R. andeanae in two distant Chilean regions, which is added to its recently finding in the Northern extreme of the country. This new rickettsial agent limits to Amblyomma ticks and rural areas, as it was reported in other American countries and corresponds with this tick habitat.
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    Identificación de Rickettsia andeanae en dos regiones de Chile
    (2013) Abarca Villaseca, Katia; López, Javier; Acosta Jamett, Gerardo; Martínez Valdebenito, Constanza Pamela
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    Prevalence and Risk Factors for Echinococcal Infection in a Rural Area of Northern Chile : A Household-Based Cross-Sectional Study
    (2014) Acosta Jamett, Gerardo; Weitzel, Thomas; Boufana, Belgees; Adones, Claudia; Bahamonde, Andrea; Abarca Villaseca, Katia; Craig, Philip S.; Reiter-Owona, Ingrid
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    Widespread Infection with Hemotropic Mycoplasmas in Free-Ranging Dogs and Wild Foxes Across Six Bioclimatic Regions of Chile
    (MDPI, 2021) Di Cataldo, Sophia; Cevidanes, Aitor; Ulloa Contreras, Claudia; Sacristan, Irene; Penaloza Madrid, Diego; Vianna, Juliana; Gonzalez Acuna, Daniel; Sallaberry Pincheira, Nicole; Cabello, Javier; Napolitano, Constanza; Hidalgo Hermoso, Ezequiel; Acosta Jamett, Gerardo; Millan, Javier
    Blood samples of 626 rural dogs, 140 Andean foxes (Lycalopex culpaeus), and 83 South American grey foxes (L. griseus) from six bioregions of Chile spanning 3000 km were screened for Mycoplasma DNA by conventional PCR and sequencing. Risk factors of infection were inferred using Generalized Linear Mixed Models and genetic structure by network analyses. Overall, Mycoplasma haemocanis/Mycoplasma haemofelis (Mhc/Mhf) and Candidatus Mycoplasma haematoparvum (CMhp) observed prevalence was 23.8% and 12.8% in dogs, 20.1% and 7.2% in Andean foxes, and 26.5% and 8.4% in grey foxes, respectively. Both hemoplasmas were confirmed in all the bioregions, with higher prevalence in those where ticks from the Rhipicephalus sanguineus species group were absent. Candidatus M. haematominutum and a Mycoplasma sp. previously found in South American carnivores were detected in one fox each. Although the most prevalent Mhc/Mhf and CMhp sequence types were shared between dogs and foxes, network analysis revealed genetic structure of Mhc/Mhf between hosts in some regions. Male sex was associated with a higher risk of Mhc/Mhf and CMhp infection in dogs, and adult age with CMhp infection, suggesting that direct transmission is relevant. No risk factor was identified in foxes. Our study provides novel information about canine hemoplasmas with relevance in distribution, transmission routes, and cross-species transmission.