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

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.

Exploring the Stony Coral Tissue Loss Disease Bacterial Pathobiome

ABSTRACTA devastating novel coral disease outbreak, referred to as Stony Coral Tissue Loss Disease (SCTLD), was first described in 2014. It is thought to have originated offshore of Miami-Dade County, FL, but has persisted and spread, affecting new reefs along the Florida Reef Tract and reefs of at least 8 other Caribbean jurisdictions. We investigated the microbial communities of clinically normal and diseased specimens of five species of affected corals using targeted 16S ribosomal DNA sequencing (Illumina MiSeq). Fifty-nine bacterial sequences were identified using contrast analysis that had enriched abundance in diseased coral host microbiomes relative to the microbiomes of clinically normal hosts. Several sequences from known bacterial pathogens were identified in this group. Additionally, we identified fifty-three bacterial species that had differentially elevated numbers in clinically normal coral host samples relative to samples from diseased host corals. The bacterial consortia composing the clinically normal and diseased coral microbiomes were clearly distinct taxonomically. Predicted functional profiles based on taxonomy, however, were found to be quite similar. This indicates a high level of functional redundancy among diseased and clinically normal microbiome members. Further examination of the direct sequencing data revealed that while some bacteria were differentially distributed according to disease status, others were not. Fifty-one bacterial species were found in both diseased and clinically normal coral host samples and not differentially abundant in either disease state. These still may be important in explaining the presentation of disease.IMPORTANCEDetermining causation is a management top priority to guide control and intervention strategies for the SCTLD outbreak. Towards this goal we examined bacterial taxa that were differentially elevated in numbers in diseased corals as compared to clinically normal corals at Looe Key, FL in August 2018. Many of the bacterial species we detected are known to be pathogenic to humans, animals, and (or) plants, and some of these have been found associated with diseased corals in other studies. Microbes that were present (or conspicuous by their absence) in both diseased as well as clinically normal corals were also examined because “healthy” corals from a diseased location such as Looe Key may have been exposed but may not have been showing overt disease at the time of sampling. Although untangling of causation is not possible currently, certain bacterial cliques and excess nutrients appear to be potential risk factors in SCTLD pathology.

Identifikasi Jenis dan Prevalensi Penyakit Karang pada Terumbu Karang di Perairan Pemuteran

Coral reef ecosystems play an important role in many aspects of human beings as one third of Indonesian population are living in coastal areas and depend their lives on this ecosystem. However, this ecosystem is threatened by various factors, one of them is coral disease. Increased sea water temperature, sedimentation, and pollutants can increase the growth of pathogenic microorganisms that cause coral disease. The data of coral diseases was collected byqpurposive samplingpmethod which was chosen based on the presence of coral reefs and coastal conditions at each station in a belt transect of 20 x 2 m. Furthermore, coral diseases and coral species were identified based on identification books. The prevalence of coral disease was calculated by divided the total number of coral colonies with the total number of diseased coral then multiplied by 100%. Results showed that the highest coral disease prevalence were at site 3 and 4. Meanwhile, site 1 and 2 were lower than those sites. It was suggested that the coral disease prevalence is related to the domestic input from the coastal. As site 1 and 2 were relatively low populated than site 3 and 4.

KARAKTERISTIK PENYAKIT WHITE BAND DISEASE DAN WHITE SYNDROME SECARA VISUAL DAN HISTOLOGI PADA KARANG Acropora sp. DARI PULAU GILI LABAK SUMENEP MADURA

ABSTRAKPenyakit white band disease dan white syndrome yang menyerang karang Acropora sp. di Pulau Gili Labak merupakan salah satu masalah yang perlu diperhatikan, sebab terjadinya kematian terumbu karang yang disebabkan oleh penyakit karang bukan hanya akan berpengaruh pada fungsi ekologis terumbu karang namun juga akan mempengaruhi fungsi ekonomis. Tujuan penelitian ini adalah untuk mendeteksi penyakit karang dengan metode histologi dengan studi kasus di Pulau Gili Labak, Poteran, Sumenep-Madura. Pengambilan sampel penelitian ini dilaksanakan pada bulan April 2017 di perairan Pulau Gili Labak Kabupaten Sumenep. Penelitian deteksi penyakit pada jaringan karang dengan metode histologi dilakukan pada Laboratorium Histologi Fakultas Kedokteran Universitas Brawijaya Malang. Analisa data dilakukan dengan metode analisa deskriptif. Ditemukan jaringan karang Acropora sp. yang terserang penyakit white band disease dan white syndrome yang terjadi banyak perbedaan antara jaringan karang yang sehat dengan yang sakit. Umumnya pada jaringan karang yang sehat terlihat susunan sel pada jaringan karang terlihat masih baik dan utuh, sedangkan pada jaringan karang yang sakit menunjukan bahwa jaringan mengalami degradasi disebabkan oleh jaringan yang lisis dan nekrosis, jaringan sakit terlihat hilang dan mulai hancur. Penyakit white band disease dicirikan dengan adanya jaringan yang mengelupas dari skeleton karang, sedangkan penyakit white syndrome hilangnya jaringan dimulai pada epidermis terlebih dahulu lalu merambat kedalam skeletonnya. ABSTRACTWhite band disease and white syndrome attacking Acropora sp. on the island of Gili Labak is one of the issues that need to be considered, because the loss of coral caused by disease will not only affect the ecological function of coral reefs but will also affect the economic function. The sampling of this research was conducted in April 2017 in the waters of Gili Labak Island of Sumenep Regency. Research on detection of coral tissue disease by histology method was done at Histology Laboratory Faculty of Medicine Universitas Brawijaya Malang. Data analysis was done by descriptive analysis method. Acropora sp. who are affected by white band disease and white syndrome showed the difference between healthy and affected coral tissues. Generally, on healthy coral tissue, the structure of the cells in coral tissue looks good and intact, whereas in diseased coral tissue show tissue degradation caused by lysis tissue and necrosis, tissue is lost and starts to disintegrate. The white band disease is characterized by the presence of peeling tissue from coral skeleton. While white syndrome disease loss of tissue begins in the epidermis first then propagate into their skeleton.

Flow cytometric analysis of virus-like particles and heterotrophic bacteria within coral-associated reef water

Using flow cytometry, two distinct populations of virus-like particles (VLP) and heterotrophic bacteria were defined within the 12 cm water layer immediately overlying healthy, diseased and dead acroporid corals. Bacterial abundances were similar in overlying water for all coral types, however, VLP were 30% higher above diseased corals than healthy or dead corals. Mean virus to bacteria ratios (VBR) were up to 30% higher above diseased corals than above healthy or dead coral or in distant water. Concomitant with increasing VLP concentrations within 5 cm of coral surfaces, VBR distributions were generally highest above healthy and diseased coral and depressed above dead coral. These results suggest fundamental shifts in the VLP and bacterial community in water associated with diseased corals.