<em>Vibrio owensii</em> Induces the Tissue Loss Disease <em>Montipora</em> White Syndrome in the Hawaiian Reef Coral <em>Montipora capitata</em>

<div><p>Incidences of coral disease in the Indo-Pacific are increasing at an alarming rate. In particular, <em>Montipora</em> white syndrome, a tissue-loss disease found on corals throughout the Hawaiian archipelago, has the potential to degrade Hawaii’s reefs. To identify the etiologic agent of <em>Montipora</em> white syndrome, bacteria were isolated from a diseased fragment of <em>Montipora capitata</em> and used in a screen for virulent strains. A single isolate, designated strain OCN002, recreated disease signs in 53% of coral fragments in laboratory infection trials when added to a final concentration of 10⁷ cells/ml of seawater. In addition to displaying similar signs of disease, diseased coral fragments from the field and those from infection trials both had a dramatic increase in the abundance of associated culturable bacteria, with those of the genus <em>Vibiro</em> well represented. Bacteria isolated from diseased fragments used in infection trails were shown to be descendants of the original OCN002 inocula based on both the presence of a plasmid introduced to genetically tag the strain and the sequence of a region of the OCN002 genome. In contrast, OCN002 was not re-isolated from fragments that were exposed to the strain but did not develop tissue loss. Sequencing of the <em>rrsH</em> gene, metabolic characterization, as well as multilocus sequence analysis indicated that OCN002 is a strain of the recently described species <em>Vibrio owensii</em>. This investigation of <em>Montipora</em> white syndrome recognizes <em>V. owensii</em> OCN002 as the first bacterial coral pathogen identified from Hawaii’s reefs and expands the range of bacteria known to cause disease in corals.</p>