RESUMEN
La rickettsiosis fueron inicialmente descritas en Colombia en 1937 por el Doctor Luis Patiño debido a un brote de una enfermedad con signos inespecíficos. El género Rickettsia esta constituido por bacterias intracelulares obligadas gram negativas que han causado varias epidemias a nivel mundial y son transmitidas principalmente por garrapatas, pulgas, piojos o ácaros. La más letal de estas enfermedades febriles se conoce como la Fiebre manchada de las montañas rocosas que es causada por la Rickettsia rickettsii, pero además existen el tifus endémico causado por la Rickettsia typhi y el tifus epidémico causado por Rickettsia prowazekii. En Colombia en los últimos años se han presentado varios brotes de rickettsiosis de la fiebres manchadas, entre los que se destacan los ocurridos en los municipios de Necoclí y Turbo ambos en el departamento de Antioquia en los años 2006 y 2008 respectivamente, y un tercero en el municipio de los Córdobas del departamento de Córdoba en el 2007. El objetivo de esta revisión es dar a conocer el estado del arte de la rickettsiosis, enfermedad letal y olvidada en nuestro medio, así como el planteamiento de preguntas motivo de preocupación para investigaciones futuras que permitan tener un mejor entendimiento de ésta entidad potencialmente endémica en algunas zonas de Colombia.
Rickettsiosis was first described in Colombia in 1937 by Dr Luis Patiño during an outbreak of a disease with unspecific signs. Rickettsia is a genus of Gram-negative intracellular obligatory bacteria having caused several epidemics around the world, and are transmitted mainly by ticks, fleas, lice and mites. The most fatal within this group of diseases is known as Rocky Mountain Spotted Fever (RMSF), which is caused by Rickettsia rickettsia. There is also the endemic typhus caused by Rickettsia typhi and epidemic typhus caused by Rickettsia prowazekii. In Colombia, several outbreaks of RMSF have occurred during the last decade. The best known among those have hit the municipalities of Necoclí and Turbo, in Antioquia in 2006 and 2008 respectively, and Los Cordobas in the department of Cordoba in 2007. The goal of this review is to describe the state of the art of rickettsiosis, a forgotten lethal disease that has re-emerged in our country, and leave some questions as an inspiration for future research that will hopefully lead scientists to a better understanding of this entity potentially endemic in some areas of Colombia.
A rickettsiose na Colômbia foi descrita pela primeira vez em 1937 pelo Dr. Luis Patiño devido a um surto de uma doença com sinais inespecíficos. O gênero Rickettsia é constituído por bactérias intracelulares obrigatórias gram-negativas que têm causado várias epidemias em todo o mundo e são transmitidas principalmente por carrapatos, pulgas, piolhos ou ácaros. A mais mortífera destas doenças febris é conhecida como a Febre Maculosa das Montanhas Rochosas que é causada por Rickettsia rickettsii, mas há também o tifo endémico causado pela Rickettsia typhi e o tifo epidêmico causado por Rickettsia prowazekii. Na Colômbia nos últimos anos tem havido vários surtos de rickettsioses do grupo das febres maculosas; destaques ocorreram nos municípios de Necocli e Turbo, no departamento de Antioquia em 2006 e 2008, respectivamente, e um terceiro no município dos Cordobas no departamento de Córdoba, em 2007. O objetivo desta revisão é apresentar o estado da arte da rickettsiose, doença letal e esquecida em nosso meio, bem como fazer perguntas de interesse para futuras pesquisas para permitir uma melhor compreensão desta entidade potencialmente endémica em algumas áreas da Colômbia.
Asunto(s)
Infecciones por Rickettsiaceae/virología , Virosis , ColombiaRESUMEN
The non-virulent Wolbachia strain wMel and the life-shortening strain wMelPop-CLA, both originally from Drosophila melanogaster, have been stably introduced into the mosquito vector of dengue fever, Aedes aegypti. Each of these Wolbachia strains interferes with viral pathogenicity and/or dissemination in both their natural Drosophila host and in their new mosquito host, and it has been suggested that this virus interference may be due to host immune priming by Wolbachia. In order to identify aspects of the mosquito immune response that might underpin virus interference, we used whole-genome microarrays to analyse the transcriptional response of A. aegypti to the wMel and wMelPop-CLA Wolbachia strains. While wMel affected the transcription of far fewer host genes than wMelPop-CLA, both strains activated the expression of some immune genes including anti-microbial peptides, Toll pathway genes and genes involved in melanization. Because the induction of these immune genes might be associated with the very recent introduction of Wolbachia into the mosquito, we also examined the same Wolbachia strains in their original host D. melanogaster. First we demonstrated that when dengue viruses were injected into D. melanogaster, virus accumulation was significantly reduced in the presence of Wolbachia, just as in A. aegypti. Second, when we carried out transcriptional analyses of the same immune genes up-regulated in the new heterologous mosquito host in response to Wolbachia we found no over-expression of these genes in D. melanogaster, infected with either wMel or wMelPop. These results reinforce the idea that the fundamental mechanism involved in viral interference in Drosophila and Aedes is not dependent on the up-regulation of the immune effectors examined, although it cannot be excluded that immune priming in the heterologous mosquito host might enhance the virus interference trait.
