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BACKGROUND AND OBJECTIVE: Social relationships, physical activity and diet have been proposed as responsible for longevity; however, many of these conditions have changed in modern societies. The objective of this study was to identify if the anthropometric status, biochemical profile and diet of Nicoyan centenarians is different from that of their decency and if the quality and diversity of the diet of these Costa Ricans differs from that of adults from urban areas of the same country. MATERIALS AND METHODS: Anthropometric, biochemical and dietary assessments were carried out on 120 adults residing in the Nicoya Peninsula, including centenarians, their children and grandchildren. The data were analyzed using descriptive and inferential statistics. RESULTS: There is a significantly lower percentage of excess weight, central adiposity and blood lipids in Nicoyan centenarians compared to their children and grandchildren. The consumption of «Dairy¼ and «Other fruits¼ is higher in centenarians than in their descendants. Centenarians showed a higher dietary diversity index (DDI) compared to other age categories, and they also showed a higher DDI and a significantly more diverse diet than the urban population of Costa Rica. CONCLUSION: Nicoyan centenarians presented a better lipid and glycemic profile than their offspring, they have lower weight and a better quality and diversity of diet than their relatives and than adults from the urban area of Costa Rica.
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Several specialised insects can manipulate normal plant development to induce a highly organised structure known as a gall, which represents one of the most complex interactions between insects and plants. Thus far, the mechanism for insect-induced plant galls has remained elusive. To study the induction mechanism of insect galls, we selected the gall induced by Iatrophobia brasiliensis (Diptera: Cecidomyiidae) in cassava (Euphorbiaceae: Manihot esculenta Crantz) as our model. PCR-based molecular markers and deep metagenomic sequencing data were employed to analyse the gall microbiome and to test the hypothesis that gall cells are genetically transformed by insect vectored bacteria. A shotgun sequencing discrimination approach was implemented to selectively discriminate between foreign DNA and the reference host plant genome. Several known candidate insertion sequences were identified, the most significant being DNA sequences found in bacterial genes related to the transcription regulatory factor CadR, cadmium-transporting ATPase encoded by the cadA gene, nitrate transport permease protein (nrtB gene), and arsenical pump ATPase (arsA gene). In addition, a DNA fragment associated with ubiquitin-like gene E2 was identified as a potential accessory genetic element involved in gall induction mechanism. Furthermore, our results suggest that the increased quality and rapid development of gall tissue are mostly driven by microbiome enrichment and the acquisition of critical endophytes. An initial gall-like structure was experimentally obtained in M. esculenta cultured tissues through inoculation assays using a Rhodococcus bacterial strain that originated from the inducing insect, which we related to the gall induction process. We provide evidence that the modification of the endophytic microbiome and the genetic transformation of plant cells in M. esculenta are two essential requirements for insect-induced gall formation. Based on these findings and having observed the same potential DNA marker in galls from other plant species (ubiquitin-like gene E2), we speculate that bacterially mediated genetic transformation of plant cells may represent a more widespread gall induction mechanism found in nature.
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Abstract: Galling insects are specialist herbivorous that have the ability of manipulating plant tissue to form complex biological structures called galls. Even though different organisms have the ability to induce galls in plants, insect galls have the highest degree of structural complexity. The main goal of this study was to obtain a preliminary systematic record of plant gall morphotypes from the Guanacaste Conservation Area in Costa Rica and integrate the information into a biological database. Plant gall morphotypes were recorded, characterized and deposited into a specialized herbarium established as a reference for the inventory. Moreover, organisms associated with gall morphotypes were included in the inventory when it was possible to obtain and identify them. Galls were collected in the rainy season over a period of three years. In total, we recorded forty-four families, seventy genera, and eighty-seven host plant species. One hundred thirty-one morphotypes of plant galls were identified in the Guanacaste Conservation Area. The family with the highest number of gall morphotypes was Fabaceae (8.4%). Leaves were the organ with the largest number of galls (71%), followed by stems (17.6%), and apical buds (6.9%). The predominant gall shape was globular (25.2%), followed by discoid (18.3%). Fifty-nine percent of the galls had a glabrous texture, which was most common on leaves, with 77%. One hundred twenty of our field records (91.6%) of plant galls were new morphotypes not only for Costa Rica but also the world. As a consequence of this research and considering the prospect of future increases in new gall records (and associated organisms), we proposed having the biological entities resulting from the inventory placed in a cecidiarium. This repository represents a standardized and comprehensive way to manage the data and biological materials associated with the plant galls. We also suggest a nomenclature for standardizing gall morphotype registries and identifications. This work is the first and most detailed inventory of plant galls carried out thus far in the Guanacaste Conservation Area.
Resumo: Os insetos galhadores são herbívoros especializados, que têm a habilidade de manipular os tecidos vegetais, formando uma complexa estrutura biológica. Diferentes organismos têm a capacidade de induzir galhas, porém as de insetos têm maior grau de complexidade estrutural. O principal objetivo desse estudo foi realizar um levantamento sistemático preliminar das galhas de insetos na Área de Conservação Guanacaste, na Costa Rica, e inserir as informações em uma base de dados biológicos. Os morfotipos de galhas foram registrados, caraterizados e depositados em um herbário estabelecido como base de referência deste inventário. Além disso, quando foi possível obter e identificar os organismos associados a cada morfotipo de galha, eles foram incluídos no inventário. As amostras de galhas foram coletadas na estação chuvosa, durante três anos. No total, foram registradas 44 famílias, 70 gêneros e 87 espécies de plantas hospedeiras. Cento e trinta e um morfotipos de galhas foram identificados na Área de Conservação de Guanacaste. A família com o maior número de morfotipos de galhas foi Fabaceae (8.4%). Os órgãos vegetais com o maior número de galhas foram as folhas (71,0%), seguidas dos caules (17,6%), e das gemas apicais com 6,9%. A forma predominante das galhas foi globoide (25,2%), seguida da lenticular (18,3%) e 59% das galhas apresentaram textura glabra, observada mais frequentemente folhas (77%). Cento e vinte morfotipos de galhas (91.6%) representaram novos registros não só na Costa Rica como também no mundo. Como consequência desta pesquisa e considerando as perspectivas de aumentos futuros de novos registros de galhas (e organismos associados), nós propomos que as entidades biológicas resultantes deste inventário sejam depositadas em um cecidiário. Este repositório representa uma maneira padronizada e abrangente de gerenciar e integrar os dados e os materiais biológicos associados às galhas das plantas. Também sugerimos uma terminologia para padronizar os registros e identificações dos morfotipos de galhas. Este inventário de galhas em plantas é o primeiro e o mais detalhado já realizado na Área de Conservação Guanacaste.
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Abstract The nematodes involved in ant-plant symbioses have been poorly studied, creating an area of research that is now receiving increasing attention. One example is Sclerorhabditis neotropicalis that inhabit the nests of Azteca ants in Cecropia trees. The goal of the present study is to increase our knowledge about these organisms and their possible symbiotic relationship with the ants and their host plant. The samples were collected during 2011-2013 in different locations in Costa Rica: Parque Nacional Carara (Puntarenas province), San Pedro de Montes de Oca and Highway 27 (San Jose) and La Selva Biological Station (Sarapiquí, Heredia). We examined 576 internodes from 23 plants, comprising four species of Cecropia (including one non-myrmecophyte) and five Azteca species. S. neotropicalis was found in all but one of the Azteca/Cecropia combinations examined. Queen and worker ants were placed in water in order to dislodge nematodes and the results were largely positive, suggesting that alate queens carry S. neotropicalis between trees and that workers carry them between internodes. In addition to transport, preliminary observations suggest that the ants provide masses of scraped parenchyma (possibly fertilized with feces) as a substrate for bacteria upon which the nematodes presumably feed. We also found S. neotropicalis associated with Azteca in another myrmecophyte, Cordia alliodora, suggesting that this ant/nematode association is not restricted to Cecropia. SEM photographs of S. neotropicalis were provided to supplement the original description of this species, and molecular phylogenetic analyses employing three different markers suggest that Sclerorhabditis forms a well-supported clade of bacteria-feeding nematodes associated with Azteca. Indirect evidence suggests that this is a mutualistic association, but the benefits to the ants remain unknown. Rev. Biol. Trop. 66(1): 368-380. Epub 2018 March 01.
Resumen Cecropia. Los nemátodos asociados a la simbiosis entre plantas y hormigas han sido poco estudiados, creando un área de investigación que está recibiendo cada vez más atención. Un ejemplo de esto es Sclerorhabditis neotropicalis, que habita en los nidos de las hormigas Azteca asociadas a árboles de Cecropia. El objetivo de este trabajo es incrementar el conocimiento sobre esta especie de nemátodo y su relación con Azteca-Cecropia. Las muestras fueron recolectadas durante 2011-2013 en diferentes localidades de Costa Rica: Parque Nacional Carara (Puntarenas), San Pedro de Montes de Oca y Ruta 27 (San José) y la Estación Biológica La Selva (Sarapiquí, Heredia). Se examinaron 576 entrenudos de 23 plantas, comprendiendo cuatro especies de Cecropia (incluyendo una especie no mirmecófita) y cinco especies de Azteca. Se encontraron individuos de S. neotropicalis en todas las combinaciones de Azteca/Cecropia examinadas. Las hormigas reinas y trabajadoras fueron colocadas en agua para observar los nematodos y los resultados fueron en gran medida positivos, lo cual sugiere que las reinas aladas transportan S. neotropicalis hacia nuevos árboles y que las trabajadoras los transportan entre los entrenudos. Además del transporte, las observaciones preliminares insinúan que las hormigas proporcionan una masa de parénquima raspado (posiblemente fertilizado con heces) como sustrato para bacterias que luego servirán de alimento a los nematodos. Adicionalmente, encontramos S. neotropicalis asociado con Azteca en otro tipo de árbol, Cordia alliodora, sugiriendo que esta asociación de hormigas/nematodos no se limita a Cecropia. Las fotografías de microscopía electrónica de S. neotropicalis obtenidas en este trabajo complementan la descripción original de esta especie. Por otra parte, los análisis filogenéticos moleculares sugieren que Sclerorhabditis forma un clado bien definido de nematodos bacteriófagos asociados con Azteca. La evidencia indirecta apunta a que se trata de una asociación mutualista, pero los beneficios para las hormigas siguen siendo desconocidos.
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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.
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Humanos , Virus Chikungunya , Dengue/prevención & control , Control de Vectores de las Enfermedades , Wolbachia , Virus Zika , Costa Rica , SimbiosisRESUMEN
Fungus-growing ants associate with multiple symbiotic microbes, including Actinobacteria for production of antibiotics. The best studied of these bacteria are within the genus Pseudonocardia, which in most fungus-growing ants are conspicuously visible on the external cuticle of workers. However, given that fungus-growing ants in the genus Atta do not carry visible Actinobacteria on their cuticle, it is unclear if this genus engages in the symbiosis with Pseudonocardia. Here we explore whether improving culturing techniques can allow for successful isolation of Pseudonocardia from Atta cephalotes leaf-cutting ants. We obtained Pseudonocardia from 9 of 11 isolation method/colony component combinations from all 5 colonies intensively sampled. The most efficient technique was bead-beating workers in phosphate buffer solution, then plating the suspension on carboxymethylcellulose medium. Placing these strains in a fungus-growing ant-associated Pseudonocardia phylogeny revealed that while some strains grouped with clades of Pseudonocardia associated with other genera of fungus-growing ants, a large portion of the isolates fell into two novel phylogenetic clades previously not identified from this ant-microbe symbiosis. Our findings suggest that Pseudonocardia may be associated with Atta fungus-growing ants, potentially internalized, and that localizing the symbiont and exploring its role is necessary to shed further light on the association (AU)
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Animales , Hormigas/microbiología , Actinomycetales/patogenicidad , Simbiosis , Actinobacteria/patogenicidad , Hongos/patogenicidad , FilogeniaRESUMEN
Enzymatic activities of bacteria isolated from the digestive tract of caterpillars and the pupal content of Automeris zugana and Rothschildia lebeau (Lepidoptera: Saturniidae). The enzymatic activities of bacteria isolated from the digestive tracts of caterpillars and the pupal contents of Automeris zugana and Rothschildia lebeau was studied. This digestive tract represents an extreme microenvironment due to its high pH and presence of antimicrobial substances secreted by the insect or derived from ingested plant tissue. At the same time, it contains large amounts of nutrient-rich food, for which microbes may compete among themselves and with the caterpillar. There is little information about the microbiota associated with tropical caterpillar guts, although bacteria from different genera have been isolated from gut and pupae samples. The study of the enzymatic activities generated by these organisms constitutes a starting point to understand their metabolic and physiological relationships with their hosts, and to find enzymes that have potential biotechnological applications. In this study we evaluated several enzymatic activities in two collections of bacteria isolated from caterpillar guts and pupae of the tropical lepidopteran species A. zugana and R. lebeau. Bacteria grown under aerobic conditions were tested for an array of enzymes, including gelatinases, caseinases, lipases, esterases, cellulases, xylanases, amylases and chitinases. Both collections displayed similar patterns of enzymatic activity. No isolate showed activity for all enzymatic tests, but as a whole, at least some bacteria in each collection were able to degrade each substrate tested. Isolates with the same taxonomic identification obtained from caterpillar guts and pupae had almost the same enzymatic activities. In both collections, it was possible to group bacterial isolates according to their enzyme activity pattern. In addition to a heterogeneous ensemble of isolates exhibiting two or less enzymatic activities, there were two groups with at least five activities that showed an apparent specialization for the substrates they were able to use. The first consisted exclusively of isolates of the family Enterobacteriaceae, which were positive for lipolytic and chitinolytic activities, but completely lacked amylasic, cellulolytic and xylanolytic activities. The second group, composed mainly of Gram-positive rods, exhibited the opposite pattern: they were positive for amylasic, cellulolytic and xylanolytic activities, lacked chitinolytic activity and had few isolates with lipolytic activity. This work forms the foundation for future research to explore the biotechnological potential of bacterial isolates from caterpillar guts. Rev. Biol. Trop. 55 (2): 401-415. Epub 2007 June, 29.
El tracto digestivo de orugas constituye un microambiente extremo, debido a su elevado pH y presencia de sustancias antimicrobianas secretadas por el insecto o derivadas del tejido vegetal ingerido. Al mismo tiempo, el intestino alberga gran cantidad de alimento, por el cual los microorganismos presentes podrían competir entre sí y con su hospedero. Existe poca información sobre la microbiota asociada con el intestino de orugas tropicales, aunque se ha demostrado la presencia de bacterias de diversos géneros tanto en el intestino como en el interior de pupas. El estudio de las actividades enzimáticas de estos microorganismos constituye un punto de partida en la comprensión de la posible relación metabólica y fisiológica que establecen con sus hospederos, a la vez que permite investigar enzimas con potenciales aplicaciones biotecnológicas. En este trabajo se evaluó la presencia de actividades gelatinolítica, caseinolítica, esterásica, lipolítica, quitinolítica, amilásica, celulolítica y xilanolítica en dos colecciones de aislamientos bacterianos provenientes de tractos digestivos de orugas y de pupas de los lepidópteros Automeris zugana y Rothschildia lebeau. Se utilizaron ensayos bioquímicos tradicionales para detectar enzimas secretadas en condiciones aerobias, en las que ambas colecciones exhibieron un comportamiento enzimático similar. Ningún aislamiento produjo un resultado positivo en todas las pruebas, pero como conjunto ambas colecciones fueron capaces de utilizar todos los sustratos evaluados. Los aislamientos obtenidos de pupas presentaron prácticamente las mismas actividades que sus homólogos provenientes de intestinos. En ambas colecciones fue posible agrupar los aislamientos de acuerdo con su patrón de producción de enzimas. Además de un conjunto heterogéneo de aislamientos poco activos (dos o menos actividades), se destacan dos grupos muy activos (al menos cinco actividades), que manifiestan una aparente especialización en los sustratos que utilizan. El primero de ellos está constituido exclusivamente por miembros de la familia Enterobacteriaceae, los cuales exhibieron un alto porcentaje de positividad en actividades lipolítica y quitinolítica, pero no demostraron la expresión de las actividades amilásica, celulolítica ni xilanolítica. El segundo grupo, formado en su gran mayoría por bacilos Gram-positivos, presenta la situación opuesta: alta positividad en actividades amilásica, celulolítica y xilanolítica, no detección de actividad quitinolítica y pocos aislamientos con actividad lipolítica. Este trabajo pretende ser la base de futuras investigaciones que exploren el potencial biotecnológico de aislamientos bacterianos provenientes del tracto digestivo de orugas.