Microbial community composition of black band disease on the coral host Siderastrea siderea from three regions of the wider Caribbean

Abstract

Microbial communities associated with black band disease (BBD) on colonies of the reef building coral Siderastrea siderea from reefs in 3 regions of the wider Caribbean were studied using 16S rRNA gene-targeted amplification, cloning, and sequencing. Samples were collected from 7 BBD-infected S. siderea colonies on 2 reefs near Lee Stocking Island, Bahamas, one reef in the Florida Keys, Florida, USA, and 2 reefs in St. Croix, US Virgin Islands. Genomic DNA extracted from BBD samples was PCR-amplified with universal bacterial primers (27F and 1492R). Seven clone libraries were constructed and 411 sequences were retrieved. All of the clone libraries were dominated by Alphaproteobacteria and contained sequences associated with bacteria of the sulfur cycle, including the first report of the molecular detection of sequences related to the sulfide-oxidizing genus Beggiatoa in BBD field samples. Additionally, all clone libraries had sequence types of bacteria associated with toxin producing dinoflagellates. These sequences were most abundant in a sewage impacted reef site in St. Croix, which also had the highest prevalence of BBD-infected colonies. Non-metric multidimensional scaling and cluster analysis showed clustering of BBD microbial communities by relative level of anthropogenic impact. The results support the hypothesis that BBD is composed of variable members of distinct physiological and toxin associated bacterial groups and that the microbial community variation is associated with environmental differences such as anthropogenic impact. We propose that with degrading water quality (i.e. increasing nutrients) certain proteobacteria thrive and increase BBD virulence. KEY WORDS: Black band disease · Coral disease · Siderastrea siderea · Microbial communities · Anthropogenic impact · Caribbean Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 362: [85][86][87][88][89][90][91][92][93][94][95][96][97][98] 2008 Ramos- Flores 1983, Richardson 1996, Cooney et al. 2002, Frias-Lopez et al. 2004, Sekar et al. 2006, Barneah et al. 2007). Members of all of these groups have been proposed as primary pathogens; however, few have been isolated into culture and Koch's postulates have not been fulfilled for any of them (Richardson 2004).The fulfillment of Koch's postulates has classically been the 'gold standard' for verifying that a suspected microbial pathogen is responsible for a specific disease. To fulfill Koch's postulates requires that the following are conclusively demonstrated: (1) the suspected causal organism must be constantly associated with the diseased host and is not present in healthy hosts; (2) the suspected organism must be cultivated into pure culture from the diseased host; (3) when a healthy host is inoculated with a pure culture of the suspected organism, it should cause the disease; and (4) the organism must be reisolated from the diseased host (Koch 1884). For coral hosts, only bacterial bleaching, sea fan aspergillosis, white plague Type II and ...

The impact of reduced pH on the microbial community of the coral Acropora eurystoma

“…In this group, clones were found related to coral bacterial symbionts previously found in the Caribbean coral Montastraea faveolata (Sunagawa et al, 2009), Siderastrea siderea (Sekar et al, 2008) and the Mediterranean coral Oculina patagonica . Although Bacteroidetes have been previously detected in healthy corals (Sekar et al, 2008), an increase in Bacteroidetes was associated with Black Band Disease (Cooney et al, 2002;Frias-Lopez et al, 2002, 2004Barneah et al, 2007). Bacteroidetes were also reported to increase in corals exposed to various stress conditions (Vega-Thurber et al, 2009).…”

Successional changes in bacterial communities during the development of black band disease on the reef coral, Montipora hispida

“…Sulfide-oxidizing Beggiatoa spp. have been reported as constituents of the BBD microbial mat (Richardson, 1996;Viehman and Richardson, 2002;Sekar et al, 2008), although ribotypes affiliated with Beggiatoa spp. were not retrieved from CP or BBD clone libraries in this study.…”

“…In addition to anoxic conditions, the presence of highly concentrated sulfide at the base of the BBD mat has been shown to cause coral tissue necrosis (Richardson et al, 1997) and there is clear evidence that Desulfovibrio spp. and other sulfate-reducing bacteria occupy microenvironmental niches within the BBD mat (Cooney et al, 2002;Frias-Lopez et al, 2002;Sekar et al, 2006Sekar et al, , 2008Viehman et al, 2006;Barneah et al, 2007). This study retrieved sequences affiliated with Deltaproteobacteria, including Desulfobacter sp.…”

“…As the BBD band forms, diurnal fluctuations of sulfide and oxygen concentrations along the vertically stratified microenvironment are expected to occur (Carlton and Richardson, 1995). Under these rapidly changing microenvironmental conditions, bacteria that can withstand such extreme fluctuations possibly become dominant in the microbial community (Sekar et al, 2008). To verify microenvironmental regimes within the changing microbial mat from CP to BBD, isolation and physiological characterization of CP-and BBD-dominating cyanobacterial cultures along with microsensor studies are currently underway.…”

Unsustainable Land Use, Sediment-Laden Runoff, and Chronic Raw Sewage Offset the Benefits of Coral Reef Ecosystems in a No-Take Marine Protected Area

“…Coral-associated microbial community is highly dynamic, with seasonal fluctuations (Kimes, Johnson, Torralba, Nelson et al, 2013), but can suffer significant phase shifts throughout environmental stress gradients (Dinsdale, Pantos, Smriga, Edwards et al, 2008;Kelly, Williams, Barott, Carlson et al, 2014), and with eutrophication (Kline, Kuntz, Breitbart, Knowlton et al, 2006), bleaching and disease (Sekar, Kaczmarsky, & Richardson, 2008;Mao-Jones, Ritchie, Jones, & Ellner, 2010;Mouchka, Hewson, & Harvell, 2010), and sea surface warming trends (Tracy, Koren, Douglas, Weil et al, 2015). A significant interaction between macroalgal and turf proliferation, and microbial impacts to Caribbean corals corals Orbicella annularis (Barott, Rodrí guez-Mueller, Youle, Marhaver, 2012) and Porites astreoides (Vega-Thurber, Burkepile, Correa, Thurber et al, 2012) was also documented.…”