Browsing by Author "Lopez, Javier"
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- ItemA 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.
- ItemAnaplasma platys in dogs, Chile(CENTER DISEASE CONTROL, 2007) Abarca, Katia; Lopez, Javier; Perret, Cecilia; Guerrero, Javier; Godoy, Paula; Veloz, Ana; Valiente Echeverria, Fernando; Leon, Ursula; Gutjahr, Constanza; Azocar, TeresaWe conducted a 16S rRNA nested PCR for the genus Ehrlichia and Ehrlichia spp. with blood samples from 30 ill dogs in Chile. Phylogenetic analysis was performed by using groESL gene amplification. We identified Anaplasma platys as 1 of the etiologic agents of canine ehrlichiosis.
- ItemCanine seroprevalence to Orientia species in southern Chile: A cross-sectional survey on the Chiloe A Island(2018) Weitzel, Thomas; Jiang, Ju; Acosta-Jamett, Gerardo; Martinez-Valdebenito, Constanza; Lopez, Javier; Richards, Allen L.; Abarca Villaseca, Katia
- ItemDetection of Rickettsia andeanae in two regions of Chile(SOC CHILENA INFECTOLOGIA, 2013) Abarca, Katia; Lopez, Javier; Acosta Jamett, Gerardo; Martinez Valdebenito, ConstanzaIntroduction: 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.
- ItemMolecular identification of Ehrlichia canis in a dog from Arica, Chile(SOC CHILENA INFECTOLOGIA, 2012) Lopez, Javier; Abarca, Katia; Isabel Mundaca, M.; Caballero, Carla; Valiente Echeverria, FernandoWe report a molecular confirmed case of canine ehrlichiosis caused by Ehrlichia canis. A 10-year old female crossbred Siberian from the city of Arica, which was infested by ticks, presented hemorrhagic manifestations (hematomas and snout bleeding) and prostration. Blood cell count revealed thrombocytopenia (30,000 platelets/mm(3)). Immunochromatographic rapid testing for E. canis IgG was positive. Amplification and sequencing of a fragment of the 16S rRNA gen from a blood sample showed 100% homology with E. can is from Peril. This is the first report of E. canis in Chile, an agent with known zoonotic potential.
- ItemMorphological and molecular identification of canine filariae in a semi-rural district of the Metropolitan Region in Chile(SOC CHILENA INFECTOLOGIA, 2012) Lopez, Javier; Valiente Echeverria, Fernando; Carrasco, Marcela; Mercado, Ruben; Abarca, KatiaIntroduction: To date, there has been no definitive confirmation of the presence of zoonotic dirofilariasis in dogs in Chile. Objectives: To study the presence of dirofilarias in blood samples from dogs collected in a semi-rural district near Santiago and to compare their frequency in dogs with and without dermatological manifestations. Methods: We examined 100 blood samples for dog filariae infections using microscopic methods (modified Knott technique). 50 dogs presented dermatological symptoms or signs compatible with filarial infections and 50 were asymptomatic. ITS-2 and 12s rDNA gene amplification by PCR and sequencing were performed in samples microscopically positive for microfilariae. Results. We observed microfilariae in 22 dogs (22%). Of these, 16/50 (32%) were symptomatic and 6/50 (12%) were asymptomatic (p = 0.02). Morphologically, the majority of microfilariae were similar to Dirofilaria repens, although many had a bigger size than previously described. Nucleotide sequencing of the amplified genes showed no more than 95% homology with the D. repens sequences available for comparison. D. reconditum and D. dracunculoides infections were also identified. Conclusions: These features might indicate the presence of new species of Dirofilaria or a D. repens close related variant in Chile.