Aspergillus sydowii and Other Potential Fungal Pathogens in Gorgonian Octocorals of the Ecuadorian Pacific.

M Mar Soler-Hurtado,Annie Machordom,José Vladimir Sandoval-Sierra,Javier Diéguez-Uribeondo,Kenneth Söderhäll

doi:10.1371/journal.pone.0165992

M Mar Soler-Hurtado, Annie Machordom + Show 3 more

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https://doi.org/10.1371/journal.pone.0165992

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Abstract

Emerging fungal diseases are threatening ecosystems and have increased in recent decades. In corals, the prevalence and consequences of these infections have also increased in frequency and severity. Coral reefs are affected by an emerging fungal disease named aspergillosis, caused by Aspergillus sydowii. This disease and its pathogen have been reported along the Caribbean and Pacific coasts of Colombia. Despite this, an important number of coral reefs worldwide have not been investigated for the presence of this pathogen. In this work, we carried out the surveillance of the main coral reef of the Ecuadorian Pacific with a focus on the two most abundant and cosmopolitan species of this ecosystem, Leptogorgia sp. and Leptogorgia obscura. We collected 59 isolates and obtained the corresponding sequences of the Internal Transcribed Spacers (ITS) of the ribosomal DNA. These were phylogenetically analyzed using MrBayes, which indicated the presence of two isolates of the coral reef pathogen A. sydowii, as well as 16 additional species that are potentially pathogenic to corals. Although the analyzed gorgonian specimens appeared healthy, the presence of these pathogens, especially of A. sydowii, alert us to the potential risk to the health and future survival of the Pacific Ecuadorian coral ecosystem under the current scenario of increasing threats and stressors to coral reefs, such as habitat alterations by humans and global climate change.

Highlights

Coral reefs are considered one of the most biologically diverse ecosystems in the marine realm [1]
We found that the gorgonian communities of these reefs, L. obscura and Leptogorgia sp. colonies, hold a large, diverse, and mostly unknown fungal community in these hosts
This fungal community includes the coral pathogen A. sydowii. This constitutes the first report of this pathogen in Ecuador and the second in the Eastern Pacific

Summary

Introduction

Coral reefs are considered one of the most biologically diverse ecosystems in the marine realm [1]. They maintain a high biomass and abundance of varied organisms [2] and provide a plethora of micro-habitats to support enormous biodiversity [3,4,5,6]. Coral reefs have experienced increasing pressures, and are disturbed by a combination of direct human impacts, e.g., habitat fragmentation and reduction of functional diversity [7], and global climate change, e.g., increasing ocean acidification and temperature, coral bleaching, etc. Both author and coauthors have currently not funding to pay publication fees Coral reefs have experienced increasing pressures, and are disturbed by a combination of direct human impacts, e.g., habitat fragmentation and reduction of functional diversity [7], and global climate change, e.g., increasing ocean acidification and temperature, coral bleaching, etc. [8].

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