title: Variation in the Presence of Anti-Batrachochytrium dendrobatidis Bacteria of Amphibians Across Life Stages and Elevations in Ecuador.
abstract: Amphibian populations are decreasing worldwide due to a variety of factors. In South America, the chytrid fungus Batrachochytrium dendrobatidis (Bd) is linked to many population declines. The pathogenic effect of Bd on amphibians can be inhibited by specific bacteria present on host skin. This symbiotic association allows some amphibians to resist the development of the disease chytridiomycosis. Here, we aimed (1) to determine for the first time if specific anti-Bd bacteria are present on amphibians in the Andes of Ecuador, (2) to monitor anti-Bd bacteria across developmental stages in a focal amphibian, the Andean marsupial tree frog, Gastrotheca riobambae, that deposits larvae in aquatic habitats, and (3) to compare the Bd presence associated with host assemblages including 10 species at sites ranging in biogeography from Amazonian rainforest (450 masl) to Andes montane rainforest (3200 masl). We sampled and identified skin-associated bacteria of frogs in the field using swabs and a novel methodology of aerobic counting plates, and a combination of morphological, biochemical, and molecular identification techniques. The following anti-Bd bacteria were identified and found to be shared among several hosts at high-elevation sites where Bd was present at a prevalence of 32.5%: Janthinobacterium lividum, Pseudomonas fluorescens, and Serratia sp. Bd were detected in Gastrotheca spp. and not detected in the lowlands (sites below 1000 masl). In G. riobambae, recognized Bd-resistant bacteria start to be present at the metamorphic stage. Overall bacterial abundance was significantly higher post-metamorphosis and on species sampled at lower elevations. Further metagenomic studies are needed to evaluate the roles of host identity, life-history stage, and biogeography of the microbiota and their function in disease resistance.
authors: Universidad Internacional Menendez Pelayo - Spain, Calle Arjona número 10 escalera 6 piso 4 puerta 4, Seville, Spain. jorgebresciano@gmail.com.
authors: J C
authors: JC
authors: Bresciano
authors: Instituto de Investigaciones Biomédicas, Facultad de Ciencias de la Salud, Universidad de las Américas (UDLA), Quito, Ecuador.|Centro Universitario de Investigación Científica y Tecnológica, Universidad Técnica del Norte (UTN), Ibarra, Ecuador.
authors: C A
authors: CA
authors: Salvador
authors: Instituto de Investigaciones Biomédicas, Facultad de Ciencias de la Salud, Universidad de las Américas (UDLA), Quito, Ecuador.
authors: C
authors: C
authors: Paz-Y-Miño
authors: Universidad Internacional Menendez Pelayo - Spain, Calle Arjona número 10 escalera 6 piso 4 puerta 4, Seville, Spain.
authors: A M
authors: AM
authors: Parody-Merino
authors: Museo Nacional de Ciencias Naturales, CSIC, José Gutiérrez Abascal 2, 28006, Madrid, Spain.
authors: J
authors: J
authors: Bosch
authors: Department of Biology, University of Massachussets, Boston, Boston, MA, 02125, USA.|Smithsonian Tropical Research Institute, Balboa, Ancón, Panama, Republic of Panama.
authors: D C
authors: DC
authors: Woodhams
mesh_terms: D000820:Animal Diseases; D000818:Animals; D001001:Anura / Q000382:microbiology; D001424:Bacterial Infections / Q000382:microbiology* / Q000662:veterinary*; D008411:Chytridiomycota; D017753:Ecosystem; D004484:Ecuador / Q000453:epidemiology; D009181:Mycoses / Q000382:microbiology* / Q000662:veterinary*; D019371:Topography, Medical
keywords: Andes; antifungal bacteria; biogeography; chytridiomycosis; life-history; microbiota