Anfibios en peligro: amenazas y estrategias efectivas de conservación

Abstract: From taxonomy, natural history, and ecology as the main fields of study of natural phenomena, we have quickly moved to concern to generate a conservation science due to the worldwide significant increase in the number of endangered species over the last 70 years. Amphibians are one of the most threatened groups because of a series of environmental and human factors, which have decimated many species of these vertebrates. Fortunately, in addition to the fact that many species have managed to overcome the threats, there are a series of actions, pillars of conservation, which have shown their effectiveness at improving the conditions of amphibians. Carrying out these actions to avoid the disappearance of more species is one of the main challenges of conservation today. Knowing and coordinating efforts, in addition to applying strategies that come from different social actors and branches of science can lead new researchers and conservationists to strengthen alliances with decision-makers to minimize the extinction pressure on these fragile species.Resumen: Del estudio de la taxonomía, la historia natural y la ecología como principales ramas de la investigación de los fenómenos naturales hemos pasado rápidamente a preocuparnos por generar la ciencia de la conservación, ya que en los últimos 70 años ha venido creciendo la cantidad de especies en peligro alrededor de mundo. Los anfibios son uno de los grupos más amenazados, por una serie de factores ambientales y humanos, lo que ha diezmado a muchas especies de estos vertebrados. Afortunadamente, además de que muchas especies han logrado sobreponerse, existen una serie de acciones, pilares de la conservación, las cuales han mostrado su efectividad en mejorar las condiciones de los anfibios. Aplicar estas acciones para evitar la desaparición de más especies es uno de los principales retos de la conservación en la actualidad. Conocer, coordinar y aplicar los esfuerzos y estrategias provenientes de diferentes actores sociales y ramas de la ciencia puede llevar a los nuevos investigadores y conservacionistas a robustecer las alianzas con los tomadores de decisiones y a minimizar la presión de extinción que se yergue sobre estas frágiles especies

Genotyping and differential bacterial inhibition of Batrachochytrium dendrobatidis in threatened amphibians in Costa Rica

Amphibians have declined around the world in recent years, in parallel with the emergence of an epidermal disease called chytridiomycosis, caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). This disease has been associated with mass mortality in amphibians worldwide, including in Costa Rica, and Bd is considered an important contributor to the disappearance of this group of vertebrates. While many species are susceptible to the disease, others show tolerance and manage to survive infection with the pathogen. We evaluated the pathogen Bd circulating in Costa Rica and the capacity of amphibian skin bacteria to inhibit the growth of the pathogen in vitro. We isolated and characterized – genetically and morphologically – several Bd isolates from areas with declining populations of amphibians. We determined that the circulating chytrid fungus in Costa Rica belongs to the virulent strain Bd-GPL- 2, which has been related to massive amphibian deaths worldwide; however, the isolates obtained showed genetic and morphological variation. Furthermore, we isolated epidermal bacteria from 12 amphibian species of surviving populations, some in danger of extinction, and evaluated their inhibitory activity against the collection of chytrid isolates. Through bioassays we confirmed the presence of chytrid-inhibitory bacterial genera in Costa Rican amphibians. However, we observed that the inhibition varied between different isolates of the same bacterial genus, and each bacterial isolation inhibited fungal isolation differently. In total, 14 bacterial isolates belonging to the genera Stenotrophomonas, Streptomyces, Enterobacter, Pseudomonas and Klebsiella showed inhibitory activity against all Bd isolates. Given the observed variation both in the pathogen and in the bacterial inhibition capacity, it is highly relevant to include local isolates and to consider the origin of the microorganisms when performing in vivo infection tests aimed at developing and implementing mitigation strategies for chytridiomycosis.United States Fish and Wildlife Service/[46-6003541]/USFWS/Estados UnidosUniversidad de Costa Rica/[801-B2-029]/UCR/Costa RicaUniversidad de Costa Rica/[810-B7-A46]/UCR/Costa RicaMinisterio de Ciencia, Tecnología y Telecomunicaciones/[849-PINN-2015-I]/MICITT/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM

Characterization of Batrachochytrium dendrobatidis Inhibiting Bacteria from Amphibian Populations in Costa Rica

Global amphibian declines and extinction events are occurring at an unprecedented rate. While several factors are responsible for declines and extinction, the fungal pathogen Batrachochytrium dendrobatidis (Bd) has been cited as a major constituent in these events. While the effects of this chytrid fungus have been shown to cause broad scale population declines and extinctions, certain individuals and relict populations have shown resistance. This resistance has been attributed in part to the cutaneous bacterial microbiome. Here, we present the first study characterizing anti-Bd bacterial isolates from amphibian populations in Costa Rica, including the characterization of two strains of Serratia marcescens presenting strong anti-Bd activity. Transcriptome sequencing was utilized for delineation of shifts in gene expression of the two previously uncharacterized strains of S. marcescens grown in three different treatments comprising Bd, heat-killed Bd, and a no Bd control. These results revealed up- and down-regulation of key genes associated with different metabolic and regulatory pathways. This information will be valuable in continued efforts to develop a bacterial-based approach for amphibian protection as well as providing direction for continued mechanistic inquiries of the bacterial anti-Bd response.Fish and Wildlife Service/[46-6003541]/USFWS/Estados UnidosUniversidad de Costa Rica/[801-B2-029]/UCR/Costa RicaGeneral Medicine Sciences of the National Institutes of Health/[P20GM103443]7NIGMS/Estados UnidosUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)UCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Medicin

Characterization of the Skin Microbiota of the Cane Toad Rhinella cf. marina in Puerto Rico and Costa Rica

Rhinella marina is a toad native to South America that has been introduced in the Antilles, likely carrying high loads of microorganisms, potentially impacting local community diversity. The amphibian skin is involved in pathogen defense and its microbiota has been relatively well studied, however, research focusing on the cane toad microbiota is lacking. We hypothesize that the skin microbial communities will differ between toads inhabiting different geographical regions in Central America and the Caribbean. To test our hypothesis, we compared the microbiota of three populations of R. cf. marina toads, two from Costa Rican (native) and one Puerto Rican (exotic) locations. In Costa Rica, we collected 11 toads, 7 in Sarapiquí and 4 from Turrialba while in Puerto Rico, 10 animals were collected in Santa Ana. Separate swab samples were collected from the dorsal and ventral sites resulting in 42 samples. We found significant differences in the structure of the microbial communities between Puerto Rico and Costa Rica. We detected as much as 35 different phyla; however, communities were dominated by Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. Alpha diversity and richness were significantly higher in toads from Puerto Rico and betadiversity revealed significant differences between the microbiota samples from the two countries. At the genus level, we found in Santa Ana, Puerto Rico, a high dominance of Kokuria, Niabella, and Rhodobacteraceae, while in Costa Rica we found Halomonas and Pseudomonas in Sarapiquí, and Acinetobacter and Citrobacter in Turrialba. This is the first report of Niabella associated with the amphibian skin. The core microbiome represented 128 Operational Taxonomic Units (OTUs) mainly from five genera shared among all samples, which may represent the symbiotic Rhinella’s skin. These results provide insights into the habitat-induced microbial changes facing this amphibian species. The differences n the microbial diversity in Puerto Rican toads compared to those in Costa Rica provide additional evidence of the geographically induced patterns in the amphibian skin microbiome, and highlight the importance of discussing the microbial tradeoffs in the colonization of new ecosystemsNational Institute of General Medical Sciences/[GM103475-15]/NIGMS/Estados UnidosMinisterio de Ciencia Tecnología y Telecomunicaciones/[849-PINN-2015-I]/MICIT/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC)UCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM

Community richness of amphibian skin bacteria correlates with bioclimate at the global scale

Animal-associated microbiomes are integral to host health, yet key biotic and abiotic factors that shape host-associated microbial communities at the global scale remain poorly understood. We investigated global patterns in amphibian skin bacterial communities, incorporating samples from 2,349 individuals representing 205 amphibian species across a broad biogeographic range. We analysed how biotic and abiotic factors correlate with skin microbial communities using multiple statistical approaches. Global amphibian skin bacterial richness was consistently correlated with temperature-associated factors. We found more diverse skin microbiomes in environments with colder winters and less stable thermal conditions compared with environments with warm winters and less annual temperature variation. We used bioinformatically predicted bacterial growth rates, dormancy genes and antibiotic synthesis genes, as well as inferred bacterial thermal growth optima to propose mechanistic hypotheses that may explain the observed patterns. We conclude that temporal and spatial characteristics of the host’s macro-environment mediate microbial diversity.National Science Foundation/[DEB-1146284]/NSF/Estados UnidosNational Science Foundation/[IOS-1121758]/NSF/Estados UnidosNational Science Foundation/[DEB-1310036]/NSF/Estados UnidosJohn Templeton Foundation/[]/JTF/Estados UnidosDeutsche Forschungsgemeinschaft/[]/DFG/AlemaniaDeutsche Forschungsgemeinschaft/[VE247/9-1]/DFG/AlemaniaCoordenação de Aperfeiçoamento de Pessoal de Nível Superior/[]/CAPES/BrasilFundação de Amparo à Pesquisa do Estado de São Paulo/[#2013/50741-7]/FAPESP/BrasilConselho Nacional de Desenvolvimento Científico e Tecnológico/[]/CNPq/BrasilSimons Foundation/[429440, WTW]//Estados UnidosDeutscher Akademischer Austauschdienst/[]/DAAD/AlemaniaUniversidad de Costa Rica/[801-B2-029]/UCR/Costa RicaMinisterio de Ciencia, Tecnología y Telecomunicaciones/[849-PINN-2015]/MICITT/Costa RicaNational Research Foundation of Korea/[2015R1D1A1A01057282]/NRF/Corea del SurUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC