The microbial profile of a tissue necrosis affecting the Atlantic invasive coral Tubastraea tagusensis

Abstract

The Southwestern Atlantic rocky reef ecosystems are undergoing significant changes due to sun-corals (Tubastraea tagusensis and T. coccinea) invasion. At Búzios Island, on the northern coast of São Paulo State, where the abundance of T. tagusensis is particularly high, some colonies are displaying tissue necrosis, a phenomenon never reported for this invasive nor any other azooxanthellate coral species. Using next-generation sequencing, we sought to understand the relationship between T. tagusensis tissue necrosis and its microbiota. Thus, through amplicon sequencing, we studied both healthy and diseased coral colonies. Results indicate a wide variety of bacteria associated with healthy colonies and an even higher diversity associated with those corals presenting tissue necrosis, which displayed nearly 25% more microorganisms. Also, as the microbial community associated with the seven healthy colonies did not alter composition significantly, it was possible to verify the microbial succession during different stages of tissue necrosis (i.e., initial, intermediate, and advanced). Comparing the microbiome from healthy corals to those in early tissue necrosis suggests 21 potential pathogens, which might act as the promoters of such disease.

Spotting disease disrupts the microbiome of infected purple sea urchins, Strongylocentrotus purpuratus

“…It has been characterized as an opportunistic pathogen of the seas urchin, Strongylocentrotus intermedius [ 44 ], and therefore may be acting as a pathogen in this study. Cyclobacteriaceae have been isolated from seawater and echinoids, likely acting as commensals [ 45 ], although they have also been associated with diseased corals [ 46 ]. Cyclobacteriaceae belong to the bacterial order Cytophagales that are known for their ability to degrade chitin and other biopolymers such as pectin, cellulose, and agar, and may be involved in carbon cycling or remineralization of organic carbon [ 47 – 50 ].…”

Spatial extent of dysbiosis in the branching coral Pocillopora damicornis during an acute disease outbreak

“…Using microbial or metabolic dysbiosis as a pre-visual indicator relies on the presence of a colony-wide response to disease, which was not observed in our study across three different sampling techniques. The coral microbiome is often considered an indicator of colony health and environmental impact 33 and dysbiosis is regularly cited as a diagnostic of coral health 6 , 13 , 31 , 32 , 34 , 35 . Dysbiosis, defined here as a significant difference in microbial or metabolomic composition between visually-diseased and visually-healthy coral tissues, was not observed in visually-healthy tissues on colonies affected by disease.…”

Manejo de espécies exóticas invasoras: experiências nacionais

“…Alguns biocidas naturais e sintéticos, assim como nanobiocidas livres e encapsulados, são promissores (Ferreira-Vançato 2021. O controle genético (Savio et al 2021) e o efeito de microrganismos patogênicos (Terra 2016;Zanotti et al 2021) sobre o coral-sol também vêm sendo avaliados, mas ainda carecem de estudos e avaliações práticas antes da implementação no ambiente natural.…”