Comparative genome analysis provides novel insight into the interaction of Aquimarina sp. AD1, BL5 and AD10 with their macroalgal host.

The Aquimarina genus is widely distributed throughout the marine environment, however little is understood regarding its ecological role, particularly when in association with eukaryotic hosts. Here, we examine the genomes of two opportunistic pathogens, Aquimarina sp. AD1 and BL5, and a non-pathogenic strain Aquimarina sp.

Multiple opportunistic pathogens can cause a bleaching disease in the red seaweed Delisea pulchra.

While macroalgae (or seaweeds) are increasingly recognized to suffer from disease, in most cases the causative agents are unknown. The model macroalga Delisea pulchra is susceptible to a bleaching disease and previous work has identified two epiphytic bacteria, belonging to the Roseobacter clade, that cause bleaching under laboratory conditions. However, recent environmental surveys have shown that these in vitro pathogens are not abundant in naturally bleached D.

Bacterial pathogens, virulence mechanism and host defence in marine macroalgae.

Macroalgae are important ecosystem engineers in temperate marine waters. The function of macroalgae is intimately linked to the composition and structure of their epibiotic bacterial, communities, and evidence has emerged that bacteria can also have a negative impact on their host by causing disease. A few examples exist where bacteria have been unambiguously linked to macroalgal disease, however in many cases, pathogenicity has not been clearly separated from saprophytic behaviour or secondary colonization after disease initiation.