Las enfermedades transmitidas por vectores y el potencial uso de Wolbachia, una bacteria endocelular obligada, para erradicarlas / Vector-borne diseases and the potential use of Wolbachia, an obligate endocellular bacterium, to eradicate them

Resumen Según la Organización Mundial de la Salud (OMS), 17% de las enfermedades infecciosas reportadas en el mundo son transmitidas por vectores artrópodos. Una alternativa para bloquear la transmisión es infectar a los vectores con una bacteria endocelular llamada Wolbachia. Diferentes investigaciones han demostrado que Wolbachia acorta la vida del mosquito, aumenta su resistencia ante la infección de algunos virus como dengue, Zika y Chikungunya, y provoca incompatibilidad citoplasmática, por lo que al liberar mosquitos machos infectados con Wolbachia en una población de hembras no infectadas los productos no son viables, disminuyendo drásticamente la población total. En el presente artículo se incluye una descripción general de las enfermedades infecciosas más comunes transmitidas por vectores así como una revisión del uso de Wolbachia como una posible herramienta para controlar su propagación.

Abstract According to the World and Health Organization (WHO), 17% of the worldwide reported infectious diseases are vector-borne. One alternative for blocking the transmission of these infectious agents is to infect the vectors with the endocellular bacterium Wolbachia. Several studies have shown that Wolbachia shortens mosquitos' lifespan and increases their resistance to some virus like Dengue, Zika or Chikungunya. Wolbachia also causes cytoplasmic incompatibility, so, when Wolbachia-infected male mosquitoes are released among an uninfected female population, the production of an offspring is not viable and the mosquito population decreases drastically. This article includes an overview of the most common vector-borne infectious diseases as well as a review of the use of Wolbachia as a possible tool for controlling the spread of vector-borne diseases.

Papel de la bacteria endosimbionte Wolbachia en el control de enfermedades vectoriales: dengue, zika y chikunkunya / (Role of endosymbiont bacteria Wolbachia in the control of vectorial diseases such as dengue, zika and chikunkunya)

ResumenWolbachia es un género de bacterias perteneciente al orden Rickettsiales, que participa en diversas relaciones simbióticas con varios organismos, principalmente artrópodos y nematodos.Debido a su capacidad para inducir ciertos fenotipos reproductivos en sus hospederos, constituye un atractivo candidato para su uso como control biológico de plagas y vectores. Con el fin de proporcionar información sobre esta bacteria y sus posibles aplicaciones de control en la lucha contra el dengue y otras enfermedades transmitidas por vectores, se realizó una revisión utilizando las bases de datos de Pubmed y BINASS. Como metodología se incluyeron artículos en lengua inglesa, referentes a Wolbachia y su uso como control biológico, entre 2001 y 2017, hallados bajo las palabras clave: Wolbachia, control biológico, dengue, zika, chikungunya. Se puede resaltar que la aplicación de esta estrategia de control biológico en Costa Rica constituye un reto que involucraría el apoyo de autoridades políticas, trabajando en conjunto con los sectores académico y comunitario.

AbstractWolbachia is a genus of bacteria belonging to the order Rickettsiales that participates in diverse symbiotic relationships with several organisms, mainly arthropods and nematodes. Due to its ability to induce certain reproductive phenotypes in its hosts, it is an attractive candidate for its use as a biological agent to control of pests and vectors. In order to provide information on this bacterium and its potential control applications in the fight against dengue and other vector-borne diseases, a review was performed using Pubmed and BINASS databases. Articles in English referring to Wolbachia and its use as biological control between 2001 and 2017 where included in the search; and were found under the key words: Wolbachia, biological control, dengue, zika, chikungunya.It can be emphasized that the implementation of this biological control strategy in Costa Rica constitutes a challenge that would involve the support of the political authorities working along with the academic and community sector.

Symbiont modulates expression of specific gene categories in Angomonas deanei

Trypanosomatids are parasites that cause disease in humans, animals, and plants. Most are non-pathogenic and some harbor a symbiotic bacterium. Endosymbiosis is part of the evolutionary process of vital cell functions such as respiration and photosynthesis. Angomonas deanei is an example of a symbiont-containing trypanosomatid. In this paper, we sought to investigate how symbionts influence host cells by characterising and comparing the transcriptomes of the symbiont-containing A. deanei (wild type) and the symbiont-free aposymbiotic strains. The comparison revealed that the presence of the symbiont modulates several differentially expressed genes. Empirical analysis of differential gene expression showed that 216 of the 7625 modulated genes were significantly changed. Finally, gene set enrichment analysis revealed that the largest categories of genes that downregulated in the absence of the symbiont were those involved in oxidation-reduction process, ATP hydrolysis coupled proton transport and glycolysis. In contrast, among the upregulated gene categories were those involved in proteolysis, microtubule-based movement, and cellular metabolic process. Our results provide valuable information for dissecting the mechanism of endosymbiosis in A. deanei.

Making sense of ocean biota: How evolution and biodiversity of land organisms differ from that of the plankton.

The oceans cover 70% of the planet’s surface, and their planktonic inhabitants generate about half the global primary production, thereby playing a key role in modulating planetary climate via the carbon cycle. The ocean biota have been under scientific scrutiny for well over a century, and yet our understanding of the processes driving natural selection in the pelagic environment – the open water inhabited by drifting plankton and free-swimming nekton – is still quite vague. Because of the fundamental differences in the physical environment, pelagic ecosystems function differently from the familiar terrestrial ecosystems of which we are a part. Natural selection creates biodiversity but understanding how this quality control of randommutations operates in the oceans − which traits are selected for under what circumstances and by which environmental factors, whether bottom-up or top-down − is currently a major challenge. Rapid advances in genomics are providing information, particularly in the prokaryotic realm, pertaining not only to the biodiversity inventory but also functional groups. This essay is dedicated to the poorly understood tribes of planktonic protists (unicellular eukaryotes) that feed the ocean’s animals and continue to run the elemental cycles of our planet. It is an attempt at developing a conceptually coherent framework to understand the course of evolution by natural selection in the plankton and contrast it with the better-known terrestrial realm. I argue that organism interactions, in particular co-evolution between predators and prey (the arms race), play a central role in driving evolution in the pelagic realm. Understanding the evolutionary forces shaping ocean biota is a prerequisite for harnessing plankton for human purposes and also for protecting the oceanic ecosystems currently under severe stress from anthropogenic pressures.

Amibas de vida libre Acanthamoeba, Balamuthia, Naegleria, Sappinia y Paravahlkampfia: agentes de infección en humano y transmisoras de microorganismos / Free-living amoebae Acanthamoeba, Balamuthia, Naegleria, and Paravahlkampfia Sappinia: agents of human infection and transmission of microorganisms

Se han reportado como agentes causales de enfermedad en humanos: Naegleria fowleri, agente causal de meningoencefalitis amibiana primaria en individuos inmunocompetentes: varias especies de género Acanthamoeba que pueden producir encefalitis granulomatosa amibiana en individuos inmunosuprimidos, úlceras corneales, lesiones en piel y otros órganos en personas inmunocompetentes; Ballamuthia mandrillares agente causal de encefalitis y lesiones en piel en personas inmunocompetentes, Sappinia pedata responsable de un caso de encefalitis en un individuo inmunocompetente y Paravahlkamphfia sp en un caso de queratitis y Paravahlkamphfia francinae en un caso de meningoencefalitis aminiana primera, en paciente en paciente inmunocompetente. No se conoce totalmente los factores de los que depende que las enfermedades producidas por amibas de vida libre se presenten, influyen la presencia de algunas enfermedades, contacto con aguas en las cuales se encuentran estas amibas, y la presencia de enzimas capaces de ejercer efecto citopático. Además el uso de lentes de contacto, algunas costumbres y necesidades humanos rompen el equilibrio ecológico, aumentando así la probabilidad de contacto del hombre con estas amibas. Se han evidenciado en ellas microorganismo en un proceso de endosimbiosis lo que por lo que amibas de vida libre intervienen en la transmisión de ciertos microorganismos patógenos y las amibas se transforman en un incubador potencial y transmisorasde agentes infecciosos. Debe investigarse sobre aspectos biológicos y la relación con el humano.

Have been reported as causative agents of disease in humans: Naegleria fowleri, the causative agent of primary amoebic meningoencephalitis in immunocompetent individuals, several species of Acanthamoeba that con cause granulomatous amoebic encephalitis in immunosuppressed individuals, corneal ulcers, skin lesions and other organs in people immunocompetent; Ballamuthia madrillares causative agent of encephalitis and skin lesions in immunocompetent persons, Sappinia pedata, responsible for a case of encephalitis in an immunocompetent individual Paravahlkamphfia sp in a case of keratitis and Paravanhlkamphfia francinae in a case of primary amoebic meningoencephalitis in an immunocompetent patient. Not fully understood the factors that it depends on diseases caused by free-living amoebae are present, influencing the presence of some diseases, contact with water where are these amoebae, and the presence of enzymes capable of the cytopathic effect. Furthermore, the use of contact lenses, some customs and human needs break the ecological balance, thereby increasing the likelihood of human contact with these amoebae. Have been evidenced in these microorganisms in the process of endosymbiosis that so the free-living amoebae in the transmission of certain pathogenic microorganisms and amoebas and become a potential incubator and transmission of infectious agents. Biological aspects should be investigated and the relationship with the human.

Bioinvaders: The acquisition of new genetic variation / Bioinvasores: Adquisición de nueva variación genética / Bioinvasores: Aquisição de nova variação genética

Given that the introduction of organisms into a new environment usually occurs in low numbers, reducing genetic diversity (the so-called bottleneck effect), and that selection further decreases diversity beyond that caused by the bottleneck, then how do some alien species, if their genetic variation is low under new conditions, succeed in evolving rapidly, becoming invasive and expanding their ranges? In this paper a series of mechanisms that allow the introduced population to acquire new genetic variations are considered. Various possible roles of epigenetic adaptation, hybridization, adaptive mutations, transposons, endosymbiosis, somatic mutations, and mitotic recombination are postulated as sources of new genetic variations. The roles of purging and biotic regulation in the successful invasions of some species is also analyzed.

La introducción de organismos a un nuevo ambiente generalmente ocurre en escaso número de individuos, lo cual determina el llamado "cuello de botella", reduciendo la variación genética, mientras que la selección reduce aún más esta variación. Entonces, ¿Cómo estos exóticos son exitosos, expanden su rango de distribución bajo nuevas condiciones, evolucionan rápidamente y se convierten en invasores, si su variación genética es baja? En el presente trabajo, se consideran una serie de mecanismos que permitirían a las poblaciones introducidas adquirir nueva variación genética. Las adaptaciones epigenéticas, la hibridización, las mutaciones adaptativas, los transposones, la endosimbiosis, las mutaciones somáticas y recombinaciones mitóticas son postuladas como fuentes de nueva variación. Además se analiza el papel de la purificación y la regulación biótica en la invasión exitosa de algunas especies.

A introdução de organismos a um novo ambiente geralmente ocorre em escasso número de indivíduos, o qual determina o chamado "efeito gargalo", reduzindo a variação genética, enquanto que a seleção reduz ainda mais esta variação. Como, então, podem estes exóticos ser bem sucedidos, expandir sua faixa de distribuição sob novas condições, evolucionar rapidamente e se converter em invasores, se sua variação genética é baixa? No presente trabalho, é considerada uma série de mecanismos que permitiriam às populações introduzidas adquirirem nova variação genética. As adaptações epigenéticas, a hibridização, as mutações adaptativas, os transposões, a endossimbiose, as mutações somáticas e recombinações mitóticas são postuladas como fontes de nova variação. Além disso, se analisa o papel da purificação e a regulação biótica na invasão bem sucedida de algumas espécies.