Papers by Olger Calderón-Arguedas
Journal of Medical Entomology, 2020
Cimex lectularius and Cimex hemipterus are the most common species of bedbugs that infest homes. ... more Cimex lectularius and Cimex hemipterus are the most common species of bedbugs that infest homes. Although case reports decreased substantially by the end of the 20th century, bed bugs, and especially C. lectularius, are currently suffering a resurgence mostly attributed to insecticide resistance, inadequate pest control, and increased travel. Here, we report, to the best of our knowledge, the first molecular confirmation of C. lectularius in Central America. Specimens were obtained from an apartment located in Heredia, Costa Rica. These specimens were identified morphologically as C. lectularius. The species identification was confirmed by amplifying and sequencing fragments of the cytochrome oxidase subunit I (COI) and the 16S rRNA (16S) genes. The phylogenetic analysis showed that the sequences obtained were more closely related to a C. lectularius mitochondrial complete genome sequence from China, with similarities of 98.84% (686/694) for COI and 98.97% (387/391) for 16S. The fin...
Rickettsia felis is an emerging human pathogen associated primarily with the cat flea Ctenocephal... more Rickettsia felis is an emerging human pathogen associated primarily with the cat flea Ctenocephalides felis. In this study, we investigated the presence of Rickettsia felis in C. felis from Guatemala and Costa Rica. Ctenocephalides felis were collected directly from dogs and cats, and analyzed by polymerase chain reaction for Rickettsia-specific fragments of 17-kDa protein, OmpA, and citrate synthase genes. Rickettsia DNA was detected in 64% (55 of 86) and 58% (47 of 81) of flea pools in Guatemala and Costa Rica, respectively. Sequencing of gltA fragments identified R. felis genotype URRWXCal2 in samples from both countries, and genotype Rf2125 in Costa Rica. This is the first report of R. felis in Guatemala and of genotype Rf2125 in Costa Rica. The extensive presence of this pathogen in countries of Central America stresses the need for increased awareness and diagnosis
Acta Médica Costarricense, 2020
Se presentan dos casos de miasis nosocomiales, ocurridos en hospitales costarricenses, cuyo agent... more Se presentan dos casos de miasis nosocomiales, ocurridos en hospitales costarricenses, cuyo agente etiológico identificado fue Blaesoxipha plinthopyga (Diptera: Sarcophagidae).
Revista De Biologia Tropical, 2017
Intradomiciliary cockroaches ( Periplaneta americana Linnaeus 1753), P. australasiae Fabricius 17... more Intradomiciliary cockroaches ( Periplaneta americana Linnaeus 1753), P. australasiae Fabricius 1775), and Blattella germanica Linnaeus 1767) were collected in a Day Care Center (CEN-CINAI) and four foodstores of the Central Market, San Jose, Costa Rica. Enterobacter aerogenes, E. agglomerans, E. gergoviae, Citrobacter freundi, Klebsiella pneumoniae, K. oxytoca, Hafnia alvei, and Pseudomonas sp. were isolated from bodywash of the insects and from their intestinal contents. Scanning electron microscopy observations of the body and negative staining specimens of intestinal contents and ultrathin sections of intestine show abundant morphotypes of bacteriae, include bacilli and curve-shaped rods, some of them with periplasmic fibers.
Revista Cubana de Medicina Tropical, 2016
Introduccion : el dengue y chikungunya son virosis antroponoticas transmitidas por Aedes aegypti ... more Introduccion : el dengue y chikungunya son virosis antroponoticas transmitidas por Aedes aegypti que afectan extensas areas del continente americano incluyendo Costa Rica. La reciente introduccion del virus Zika representa un nuevo reto para los sistemas de salud. Dada la ausencia de tratamiento antiviral y vacunas, el control del vector Ae. aegypti, representa la unica alternativa para minimizar el impacto de estas virosis. En Costa Rica, el control quimico del vector se hace mediante la aplicacion de piretroides (cipermetrina y deltametrina) y del organofosforado temefos; de ahi la importancia de detectar la aparicion de resistencia a estos insecticidas. Objetivo: determinar el nivel de resistencia a temefos, cipermetrina y deltametrina en tres cepas de Ae. aegypti de la Region Caribe de Costa Rica, asi como los mecanismos de detoxificacion enzimatica correspondientes. Metodos: la resistencia a temefos, cipermetrina y deltametrina se evaluo mediante bioensayos larvarios. Grupos de...
Ticks and Tick-borne Diseases, 2017
Rickettsiae are intracellular bacteria commonly associated with hematophagous arthropods. Most of... more Rickettsiae are intracellular bacteria commonly associated with hematophagous arthropods. Most of them have been described in hard ticks, but some have been found in soft ticks. Here we report the detection and isolation of a new Rickettsia from Ornithodoros knoxjonesi larvae collected from Balantiopteryx plicata (Emballonuridae) in Nicoya, Costa Rica. Two ticks were processed to detect Rickettsia spp. genes gltA, ompA, ompB, and htrA by PCR. Part of the macerate was also inoculated into Vero E6 and C6/36 cell lines, and cells were evaluated by Giménez stain, indirect immunofluorescence assay (IFA), and PCR. Both ticks were positive by PCR and rickettsial growth was successful in Vero E6 cells. Amplification and sequencing of near full length rrs, gltA, sca4 genes, and fragments of ompA and ompB showed that the Rickettsia sp. was different from described species. The highest homologies were with 'Candidatus Rickettsia wissemanii' and Rickettsia peacockii: 99.70% (1321/1325) with both sequences for rrs, 99.58% (1172/1177) and 99.76% (1246/1249) for gltA, 99.26% with both sequences (2948/2970 and 2957/2979) for sca4, 98.78% (485/491) and 98.39% (2069/2115) for ompA, and 98.58 (1453/1474) and 98.92% (1459/1475) for ompB; respectively. Bat blood, spleen, liver, and lung samples analyzed for Rickettsia detection were negative. Results demonstrate that the Rickettsia isolated from O. knoxjonesi is probably an undescribed species that belongs to the spotted fever group, for which 'Candidatus Rickettsia nicoyana' is proposed. Considering that B. plicata inhabits areas where contact with humans may occur and that human parasitism by Ornithodoros has been reported in the country, it will be important to continue with the characterization of this species and its pathogenic potential.
Ticks and Tick-borne Diseases, 2016
Outbreaks of spotted fevers have been reported in Costa Rica since the 1950s, although vectors re... more Outbreaks of spotted fevers have been reported in Costa Rica since the 1950s, although vectors responsible for transmission to humans have not been directly identified. In this study, species of Rickettsia were detected in ectoparasites from Costa Rica, mostly from five study sites where cases of spotted fevers have been reported. Ticks and fleas were collected using drag cloths or directly from domestic and wild animals and pooled according to species, host, and location. Pools were analyzed initially by PCR to detect a fragment of Rickettsia spp. specific gltA gene, and those positive were confirmed by detection of htrA and/or ompA gene fragments. Partial sequences of the gltA gene were obtained, as well as at least one htrA and/or ompA partial sequence of each species. Rickettsia spp. were confirmed in 119 of 497 (23.9%) pools of ticks and fleas analyzed. Rickettsia rickettsii was identified in one nymph of Amblyomma mixtum and one nymph of Amblyomma varium. Other rickettsiae present were ‗Candidatus Rickettsia amblyommii' in A. mixtum, Amblyomma ovale, Dermacentor nitens, and Rhipicephalus sanguineus s. l.; Rickettsia bellii in Amblyomma sabanerae; Rickettsia felis in Ctenocephalides felis; and Rickettsia sp. similar to ‗Candidatus R. asemboensis' in C. felis, Pulex simulans, A. ovale, Rhipicephalus microplus, and A. mixtum. Results show the presence of rickettsiae in vectors that may be responsible for transmission to humans in Costa Rica, and evidence suggests exposure to rickettsial organisms in the human environment may be common. This is the first study to report R. rickettsii in A. varium and in A. mixtum in Costa Rica.
Revista Costarricense De Salud Publica, Jun 1, 2014
Ticks and Tick-borne Diseases, 2016
Exposure of dogs to spotted fever group rickettsiae in urban sites associated with human ricketts... more Exposure of dogs to spotted fever group rickettsiae in urban sites associated with human rickettsioses in Costa Rica.Ticks and Tick-borne Diseases http://dx.
Revista Cubana De Medicina Tropical, Mar 5, 2015
Introducción: el dengue constituye la principal enfermedad de transmisión vectorial en Costa Rica... more Introducción: el dengue constituye la principal enfermedad de transmisión vectorial en Costa Rica. El control del vector Aedes aegypti consiste en la aplicación de piretrinas y temefós, por lo cual es importante monitorear la aparición de resistencia a estos insecticidas. Materiales y métodos: se efectuaron bioensayos con larvas de Ae. aegypti procedentes del cantón de Guácimo en la Región Caribe de Costa Rica. Grupos de 20 larvas fueron expuestos por 24 horas a concentraciones de insecticidas que provocaran una mortalidad entre el 2 y el 100 %. Las pruebas fueron efectuadas por quintuplicado y se calculó la concentración letal 50 % (CL50). Como control susceptible se empleó la cepa Rockefeller. Un radio de resistencia 50 % (RR50) fue calculado para cada insecticida. En caso de resistencia se repitieron los ensayos exponiendo las larvas a butóxido de piperonilo (PB) y S, S, S, tributilfosforotritioato (DEF) para perfilar el mecanismo enzimático vinculado con dicha resistencia. Resultados: no se observó resistencia a temefós y deltametrina, pero sí se encontró resistencia incipiente a la cipermetrina (CL50 = 0,00845 mg/L, rango: 0,00664-0,01038, RR50 = 6,07). El análisis con sinergistas determinó un radio de singergismo (RS) de 19,2 para el PB y de 0,9 para DEF. Discusión: los resultados demuestran que existe un proceso de desarrollo de resistencia a la cipermetrina en los mosquitos Ae. aegypti en esta localidad, el cual está relacionada con la actividad citocromo P450 monooxigenasa. Esto alerta a las autoridades para sustituir dicho insecticida y así asegurar el adecuado control del vector sin la generación de resistencia.
Revista costarricense de ciencias médicas
ABSTRACT
Revista de biologia tropical
Revista costarricense de ciencias médicas
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Papers by Olger Calderón-Arguedas