First Record of Black Band Disease in the Hawaiian Archipelago: Response, Outbreak Status, Virulence, and a Method of Treatment

A high number of coral colonies, Montipora spp., with progressive tissue loss were reported from the north shore of Kaua‘i by a member of the Eyes of the Reef volunteer reporting network. The disease has a distinct lesion (semi-circular pattern of tissue loss with an adjacent dark band) that was first observed in Hanalei Bay, Kaua‘i in 2004. The disease, initially termed Montipora banded tissue loss, appeared grossly similar to black band disease (BBD), which affects corals worldwide. Following the initial report, a rapid response was initiated as outlined in Hawai‘i’s rapid response contingency plan to determine outbreak status and investigate the disease. Our study identified the three dominant bacterial constituents indicative of BBD (filamentous cyanobacteria, sulfate-reducing bacteria, sulfide-oxidizing bacteria) in coral disease lesions from Kaua‘i, which provided the first evidence of BBD in the Hawaiian archipelago. A rapid survey at the alleged outbreak site found disease to affect 6-7% of the montiporids, which is higher than a prior prevalence of less than 1% measured on Kaua‘i in 2004, indicative of an epizootic. Tagged colonies with BBD had an average rate of tissue loss of 5.7 cm2/day over a two-month period. Treatment of diseased colonies with a double band of marine epoxy, mixed with chlorine powder, effectively reduced colony mortality. Within two months, treated colonies lost an average of 30% less tissue compared to untreated controls

Vibrio coralliilyticus Strain OCN008 Is an Etiological Agent of Acute Montipora White Syndrome

Identification of a pathogen is a critical first step in the epidemiology and subsequent management of a disease. A limited number of pathogens have been identified for diseases contributing to the global decline of coral populations. Here we describe Vibrio coralliilyticus strain OCN008, which induces acute Montipora white syndrome (aMWS), a tissue loss disease responsible for substantial mortality of the coral Montipora capitata in Ka ne‘ohe Bay, Hawai‘i. OCN008 was grown in pure culture, recreated signs of disease in experimentally infected corals, and could be recovered after infection. In addition, strains similar to OCN008 were isolated from diseased coral from the field but not from healthy M. capitata. OCN008 repeatedly induced the loss of healthy M. capitata tissue from fragments under laboratory conditions with a minimum infectious dose of between 107 and 108 CFU/ml of water. In contrast, Porites compressa was not infected by OCN008, indicating the host specificity of the pathogen. A decrease in water temperature from 27 to 23°C affected the time to disease onset, but the risk of infection was not significantly reduced. Temperature-dependent bleaching, which has been observed with the V. coralliilyticus type strain BAA-450, was not observed during infection with OCN008. A comparison of the OCN008 genome to the genomes of pathogenic V. coralliilyticus strains BAA-450 and P1 revealed similar virulence-associated genes and quorum-sensing systems. Despite this genetic similarity, infections of M. capitata by OCN008 do not follow the paradigm for V. coralliilyticus infections established by the type strain

6-OHDA-induced dopaminergic neurodegeneration in <i>Caenorhabditis elegans</i> is promoted by the engulfment pathway and inhibited by the transthyretin-related protein TTR-33

<div><p>Oxidative stress is linked to many pathological conditions including the loss of dopaminergic neurons in Parkinson’s disease. The vast majority of disease cases appear to be caused by a combination of genetic mutations and environmental factors. We screened for genes protecting <i>Caenorhabditis elegans</i> dopaminergic neurons from oxidative stress induced by the neurotoxin 6-hydroxydopamine (6-OHDA) and identified the <u>t</u>rans<u>t</u>hyretin-<u>r</u>elated gene <i>ttr-33</i>. The only described <i>C</i>. <i>elegans</i> transthyretin-related protein to date, TTR-52, has been shown to mediate corpse engulfment as well as axon repair. We demonstrate that TTR-52 and TTR-33 have distinct roles. TTR-33 is likely produced in the posterior arcade cells in the head of <i>C</i>. <i>elegans</i> larvae and is predicted to be a secreted protein. TTR-33 protects <i>C</i>. <i>elegans</i> from oxidative stress induced by paraquat or H₂O₂ at an organismal level. The increased oxidative stress sensitivity of <i>ttr-33</i> mutants is alleviated by mutations affecting the KGB-1 MAPK kinase pathway, whereas it is enhanced by mutation of the JNK-1 MAPK kinase. Finally, we provide genetic evidence that the <i>C</i>. <i>elegans</i> cell corpse engulfment pathway is required for the degeneration of dopaminergic neurons after exposure to 6-OHDA. In summary, we describe a new neuroprotective mechanism and demonstrate that TTR-33 normally functions to protect dopaminergic neurons from oxidative stress-induced degeneration, potentially by acting as a secreted sensor or scavenger of oxidative stress.</p></div

The structural characterization of (NH4)2B10H10 and thermal decomposition studies of (NH4)2B10H10 and (NH4)2B12H12

The structure of (NH4)2B10H10 (1) was determined through powder XRD analysis. The thermal decomposition of 1 and (NH4)2B12H12 (2) was examined between 20 and 1000oC using STMBMS methods. Between 200 and 400oC a mixture of NH3 and H2 evolves from both compounds; above 400oC only H2 evolves. The dihydrogen bonding interaction in 1 is much stronger than that in 2. The stronger dihydrogen bond in 1 resulted in a significant reduction by up to 60oC, but with a corresponding 25% decrease in the yield of H2 in the lower temperature region and a doubling of the yield of NH3. The decomposition of 1 follows a lower temperature exothermic reaction pathway that yields substantially more NH3 than the higher temperature endothermic pathway of 2. Heating of 1 at 250oC resulted in partial conversion of B10H102 to B12H122 Both 1 and 2 form an insoluble polymeric material after decomposition. The elements of the reaction network that control the release of H2 from the B10H102 can be altered by conducting the experiment under conditions in whichpressures of NH3 and H2 are either near, or away from, their equilibrium values

Phylogenetic relationship of <i>Beggiatoa</i> spp. isolated from disease lesions from Kaua‘i to other <i>Beggiatoa</i>.

<p>A phylogenetic tree was generated using the Maximum Likelihood method with sequences from 14 other <i>Beggiatoa</i> and closely related sulfur-oxidizing strains including representative type strains from the Thiotrichaceae family. No 16S rRNA gene sequences from <i>Beggiatoa</i> found in BBD from other regions were available for comparison. The tree with the highest log likelihood is shown, and 1000 bootstrap replicates were used. NCBI accession numbers are in brackets, and bootstrap values are indicated at branch nodes. Scale bar represents five substitutions per 100 nucleotide positions.</p

Phylogenetic relationship of cyanobacterium OCN074, isolated from disease lesions from Kaua‘i, to other cyanobacteria.

<p>All 16S rRNA gene sequences from the three Kaua‘i BBD cyanobacterial isolates were identical. A phylogenetic tree was generated using the Maximum Likelihood method. The ‘*’ indicates cyanobacteria associated with BBD of Palau (*[<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0120853#pone.0120853.ref042" target="_blank">42</a>]) the Red Sea (**[<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0120853#pone.0120853.ref041" target="_blank">41</a>]), and the Florida Keys (***[<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0120853#pone.0120853.ref043" target="_blank">43</a>]). The tree with the highest log likelihood is shown, and 1000 bootstrap replicates were used. NCBI accession numbers are in brackets and bootstrap values are indicated at branch nodes. Scale bar represents two substitutions per 100 nucleotide positions.</p

The lesion occlusion method of disease treatment.

<p>A) Infected <i>M</i>. <i>capitata</i> before treatment. B) Colony with marine epoxy over lesion and with a band of epoxy placed as a “firebreak” approximately 5 cm away. C) Same colony two months post-treatment. Note that the marine epoxy is overgrown with algae and the edge of the lesion is starting to grow over the epoxy. D) Control infected <i>M</i>. <i>capitata</i> before marking with marine epoxy. E) Colony with marine epoxy approximately 5 cm behind lesion. F) Control colony after two months.</p

Phylogenetic relationship of sulfate-reducing bacteria from disease lesions from Kaua‘i to other sulfate-reducing bacteria.

<p>A phylogenetic tree was generated using the Maximum Likelihood method with a reference sequence library built from 25 known <i>dsrA</i> gene sequences used as a proxy for the presence of sulfate-reducing bacteria [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0120853#pone.0120853.ref023" target="_blank">23</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0120853#pone.0120853.ref033" target="_blank">33</a>]. The ‘*’ indicates gene sequences from BBD samples previously published from the Great Barrier Reef (* [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0120853#pone.0120853.ref033" target="_blank">33</a>]), and the Red Sea (** [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0120853#pone.0120853.ref023" target="_blank">23</a>]). The tree with the highest log likelihood is shown, and 1000 bootstrap replicates were used. NCBI accession numbers are in brackets, and bootstrap values are indicated at branch nodes. Scale bar represents two substitutions per 100 nucleotide positions.</p

<i>Montipora capitata</i> colony with signs of black band disease.

<p><i>Montipora capitata</i> colony with signs of black band disease.</p