Tick-borne rickettsial pathogens in naturally infected dogs and dog-associated ticks and their role as sentinels of zoonotic rickettsial diseases in Medellin, Colombia

ABSTRACT: Tick-borne rickettsial pathogens (TBRP) are important causes of infections in both dogs and humans. Dogs play an important role as a biological host for several tick species and can serve as sentinels for rickettsial infections. Our aim was to determine the presence of TBRP in dogs and in dog-associated ticks and their potential risk to human diseases in Medellin, Colombia. DNA for E. canis (16S rRNA and dsb) and A. platys (groEl) was detected in 17.6% (53/300) and 2.6% (8/300) of dogs, respectively. Antibodies against Ehrlichia spp. 82 (27.3%) and Anaplasma spp. 8 (2.6%) were detected in dogs. Antibody reactivity against both agents were found in 16 dogs (5.3%). Eight dogs showed antibody for Rickettsia spp. with titers that suggest 3 of them had a probable exposure to R. parkeri. Rhipicephalus sanguineus s.l. (178/193) was the main tick in dogs, followed by R. microplus (15/193). The minimum infection rates (MIR) in R. sanguineus were 11.8% for E. canis and 3.4% for A. platys. Our results indicate that E. canis and A. platys are the main TBRP infecting dogs and ticks in Medellin, Colombia. Interestingly, we found serological evidence of exposure in dogs for spotted fever group rickettsiae.RESUMEN: Los patógenos rickettsiales transmitidos por garrapatas (TBRP) son causas importantes de infecciones tanto en perros como en humanos. Los perros juegan un papel importante como hospedadores biológicos de varias especies de garrapatas y pueden servir como centinelas para las infecciones por rickettsias. Nuestro objetivo fue determinar la presencia de TBRP en perros y garrapatas asociadas a perros y su riesgo potencial de enfermedades humanas en Medellín, Colombia. Se detectó ADN para E. canis (ARNr 16S y dsb) y A. platys (groEl) en el 17,6% (53/300) y el 2,6% (8/300) de los perros, respectivamente. Anticuerpos contra Ehrlichia spp. 82 (27,3%) y Anaplasma spp. 8 (2,6%) se detectaron en perros. Se encontró reactividad de anticuerpos contra ambos agentes en 16 perros (5,3%). Ocho perros mostraron anticuerpos contra Rickettsia spp. con títulos que sugieren que 3 de ellos tuvieron una probable exposición a R. parkeri. Rhipicephalus sanguineus s.l. (178/193) fue la principal garrapata en perros, seguida por R. microplus (15/193). Las tasas mínimas de infección (MIR) en R. sanguineus fueron 11,8% para E. canis y 3,4% para A. platys. Nuestros resultados indican que E. canis y A. platys son las principales TBRP que infectan a perros y garrapatas en Medellín, Colombia. Curiosamente, encontramos evidencia serológica de exposición en perros a las rickettsias del grupo de fiebre manchada

Diseño y validación analítica de una PCR duplex para la detección de Ehrlichia y Rickettsia en garrapatas

ABSTRACT: Ehrlichia and Rickettsia are two major rickettsial genera transmitted by ticks that affect a number of wild and domestic animal species and human populations around the world. Objective: To design and validate a duplex PCR for Ehrlichia and Rickettsia in ticks. Methods:Assay validation included testing for sensitivity,specificity, reproducibility, and robustness of the PCR. The groELand 23sr RNAgenes were used for Ehrlichia and Rickettsia, respectively. Results: The limit of detection was one hundred gene copies per 50 μLof reaction for Ehrlichia spp, and one gene copy of Rickettsia per 50 μL of reaction. In general, the primers of the test only amplified in silico those bacterial agents for which they were originally designed, with the exception of the primers for Rickettsia that also amplified Methylocystis sp. The test was reproducible (intermediate precision) 96.7% of the times for both agents. The test was robust enough to tolerate concentration changes of all reagents with the exception of Taq DNA polymerase. Conclusions: The validation results indicated that this PCR is useful for detection in both bacterial genera and it is a good candidate for diagnostic validation.RESUMEN: Ehrlichia spp. y Rickettsia spp.son dos de los principales géneros rickettsiales transmitidos por garrapatas que afectan a animales silvestres, domésticos y humanos alrededor del mundo. Objetivo: diseñar y validar una prueba PCR duplex para Ehrlichia y Rickettsia en garrapatas. Métodos: la validación de la prueba incluyó ensayos de sensibilidad, especificidad, reproducibilidad y robustez. En la PCR se usó groEL y ARNr 23S como genes blanco para Ehrlichia y Rickettsia, respectivamente. Resultados: el límite de detección fue de 100 copias del gen por 50 μL de reacción para Ehrlichia spp y una copia del gen de Rickettsia por 50 μLde reacción. En general, los cebadores de la prueba solo amplificaron in silico los agentes bacterianos para los cuales fueron originalmente diseñados, con la excepción de los cebadores de Rickettsia que también amplificaron Methylocystis sp. La prueba fue reproducible (precisión intermedia) en un 96.7% de las veces para ambos agentes. La prueba fue suficientemente robusta como para tolerar cambios de concentración de los diferentes reactivos, con excepción de la Taq DNA polimerasa. Conclusión: los resultados de validación indican que la PCR es útil para detectar ambos géneros bacterianos y podría usarse para validación diagnóstica

Síndrome de Gorlin: a propósito de un caso

We present the case of a 73 year old man with a six month history of an ulcerated, painful, and erythematous nodule in the left inner thigh. He presented with multiple pigmented shined plates in his bod and palmar and plantar pits. Microscopic evaluation revealed a basal cell carcinoma of nodular adenoid and pigmented subtype. In his chest and maxillary X rays no abnormalities were seen. Based on clinical and histological findings a diagnosis of a basal cell nevus syndrome was made. Basal cell nevus syndrome is an autosomal dominant disease, uncommon, identified based on clinical criteria, early and appropriate diagnosis is essential in order to prevent tissue destruction.Se presenta el caso de un hombre de 73 años con un cuadro de seis meses de evolución de un nódulo eritematoso, ulcerado, doloroso, en la cara interna del muslo izquierdo. Al examen físico se encontraron, además de su nódulo, pits palmoplantares y múltiples placas pigmentadas y perladas, en toda la superficie corporal, identificadas histológicamente como carcinomas basocelulares de subtipo nodular, adenoideo y pigmentado. No presentaba otras anomalías en la radiografía de tórax o en la panorámica de maxilares. Basados en los hallazgos clínicos e histopatológicos se hizo un diagnóstico de síndrome de los nevos basocelulares, enfermedad de herencia autosómica dominante, poco común, que se identifica con base en criterios clínicos y cuyo diagnóstico precoz y tratamiento adecuado son fundamentales para prevenir la destrucción tisular secundaria a los tumores y la deformación oro-maxilo-facial. Teniendo en cuenta este representativo caso de una enfermedad poco común, se realiza a continuación una breve revisión de la literatura

Design and analytical validation of a duplex PCR for Ehrlichia and Rickettsia detection in ticks

Abstract Background: Ehrlichia and Rickettsia are two major rickettsial genera transmitted by ticks that affect a number of wild and domestic animal species and human populations around the world. Objective: To design and validate a duplex PCR for Ehrlichia and Rickettsia in ticks. Methods: Assay validation included testing for sensitivity, specificity, reproducibility, and robustness of the PCR. The groEL and 23sr RNA genes were used for Ehrlichia and Rickettsia, respectively. Results: The limit of detection was one hundred gene copies per 50 μL of reaction for Ehrlichia spp, and one gene copy of Rickettsia per 50 μL of reaction. In general, the primers of the test only amplified in silico those bacterial agents for which they were originally designed, with the exception of the primers for Rickettsia that also amplified Methylocystis sp. The test was reproducible (intermediate precision) 96.7% of the times for both agents. The test was robust enough to tolerate concentration changes of all reagents with the exception of Taq DNA polymerase. Conclusions: The validation results indicated that this PCR is useful for detection in both bacterial genera and it is a good candidate for diagnostic validation.Resumo Antecedentes: Ehrlichia e Rickettsia são dois dos principais gêneros de rickettsias transmitidos por carrapatos que infectam tanto animais selvagens quanto animais domésticos e até homens em todo o mundo. Objetivo: O objetivo principal foi elaborar e validar uma PCR duplex para Ehrlichia e Rickettsia em carrapatos. Métodos: A validação incluiu testes de sensibilidade, especificidade, reprodução e robustez. Para o PCR, utilizamos os genes groEl e 23Sr-RNA para Ehrlichia e Rickettsia, respectivamente. Resultados: O limite de detecção foi de 100 cópias de genes por 50 ml de reação para Erliquia spp e uma cópia de gene de Rickettsia por 50 ml de reação. Em geral, os iniciadores dos testes amplificaram em modelos computacionais os agentes bacterianos para os quais eles foram projetados, exceto os primers de Rickettsia que também amplificou Methylocystis sp. Os testes foram reproduzíveis (precisão intermediária) 96,7% para ambos os agentes e foram também robustos para tolerar mudanças de concentração em todos os reagentes, exceto o reagente Taq DNA polymerase. Conclusões: Os resultados da validação indicaram que o PCR é útil para detecção em ambos os gêneros bacterianos, portanto, um bom exame para validação diagnóstica.Resumen Antecedentes: Ehrlichia spp. y Rickettsia spp. son dos de los principales géneros rickettsiales transmitidos por garrapatas que afectan a animales silvestres, domésticos y humanos alrededor del mundo. Objetivo: Diseñar y validar una prueba PCR dúplex para Ehrlichia y Rickettsia en garrapatas. Métodos: La validación de la prueba incluyó ensayos de sensibilidad, especificidad, reproducibilidad y robustez. En la PCR se usó groEL y ARNr 23S como genes blanco para Ehrlichia y Rickettsia, respectivamente. Resultados: El límite de detección fue de 100 copias del gen por 50 μL de reacción para Ehrlichia spp y una copia del gen de Rickettsia por 50 μL de reacción. En general, los cebadores de la prueba solo amplificaron in silico los agentes bacterianos para los cuales fueron originalmente diseñados, con la excepción de los cebadores de Rickettsia que también amplificaron Methylocystis sp. La prueba fue reproducible (precisión intermedia) en un 96.7% de las veces para ambos agentes. La prueba fue suficientemente robusta como para tolerar cambios de concentración de los diferentes reactivos, con excepción de la Taq DNA polimerasa. Conclusión: Los resultados de validación indican que la PCR es útil para detectar ambos géneros bacterianos y podria usarse para validación diagnostica

Design and analytical validation of a duplex PCR for Ehrlichia and Rickettsia detection in ticks

Abstract Background: Ehrlichia and Rickettsia are two major rickettsial genera transmitted by ticks that affect a number of wild and domestic animal species and human populations around the world. Objective: To design and validate a duplex PCR for Ehrlichia and Rickettsia in ticks. Methods: Assay validation included testing for sensitivity, specificity, reproducibility, and robustness of the PCR. The groEL and 23sr RNA genes were used for Ehrlichia and Rickettsia, respectively. Results: The limit of detection was one hundred gene copies per 50 μL of reaction for Ehrlichia spp, and one gene copy of Rickettsia per 50 μL of reaction. In general, the primers of the test only amplified in silico those bacterial agents for which they were originally designed, with the exception of the primers for Rickettsia that also amplified Methylocystis sp. The test was reproducible (intermediate precision) 96.7% of the times for both agents. The test was robust enough to tolerate concentration changes of all reagents with the exception of Taq DNA polymerase. Conclusions: The validation results indicated that this PCR is useful for detection in both bacterial genera and it is a good candidate for diagnostic validation

Naturaleza urbana. Plataforma de experiencias

Naturaleza Urbana presenta experiencias autogestionadas que, con el tiempo, se han posicionado como ejercicios alternativos de identificación, monitoreo y recuperación de la biodiversidad urbana. En otros casos, el modelo comunidad-gobierno ha permitido desarrollar diagnósticos y propuestas de gestión corresponsables y sistémicas, entendiendo por esto último iniciativas que nacen desde los valores mismos que cada comunidad le atribuye a su biodiversidad. Del mismo modo, se presentan esfuerzos gubernamentales que han enriquecido la visión ambiental de los principales instrumentos de planificación urbana, por ejemplo, integrando la condición propiamente urbana como oportunidad para aumentar la oferta ambiental de la ciudad, fortaleciendo las funciones y procesos de la biodiversidad y revitalizando, con ello, la calidad de vida del entorno urbano. Por su parte, las universidades y los centros de investigación se han sumado a la ola emergente de generación de conocimiento en biodiversidad urbana (fenómeno nacional e internacional), han brindado evidencia científica de su valor para el bienestar humano y han propuesto reflexiones y lineamientos cualitativos de biodiversidad, con miras a hacer del ordenamiento un ejercicio más coherente con cada contexto territorial en particular.Bogotá, D. C., ColombiaInstituto de Investigación de Recursos Biológicos Alexander von Humbold

Urban Nature

Preservation, restoration, monitoring of biodiversity and promotion of native species, in their strict and classical sense, could be unviable strategies in the cities. Management systems such as the protected areas acquire profoundly different connotations and objectives from the traditional ones when thought of in the context of a city. Similarly, although ecological restoration seeks to return to a baseline ecosystem, there is little that we know about the vegetation present on the urban borders of the main Colombian cities prior to the 20th century. Finally, the models for potential distribution of species could produce unreliable results, because their methodological bases were not conceived based on urban dynamics. In this context, to de ne urban biodiversity and what strategy must be applied for its conservation implies a challenge that, beyond being scienti c, is necessarily social and cultural and involves planning and design. Innovation is inevitable.Bogotá, D. C

Performance of a modular ton-scale pixel-readout liquid argon time projection chamber

International audienceThe Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements, and provide comparisons to detector simulations

Performance of a modular ton-scale pixel-readout liquid argon time projection chamber

International audienceThe Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements, and provide comparisons to detector simulations

Performance of a modular ton-scale pixel-readout liquid argon time projection chamber

The Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements, and provide comparisons to detector simulations