Gliding motility proteins GldJ and SprB contribute to virulence.

causes columnaris disease in fish. Columnaris disease is incompletely understood, and adequate control measures are lacking. The type IX secretion system (T9SS) is required for gliding motility and virulence.

Secreted peptidases contribute to virulence of fish pathogen .

causes columnaris disease in freshwater fish in both natural and aquaculture settings. This disease is often lethal, especially when fish population density is high, and control options such as vaccines are limited. The type IX secretion system (T9SS) is required for virulence, but secreted virulence factors have not been fully identified.

Type IX Secretion System Effectors and Virulence of the Model Flavobacterium columnare Strain MS-FC-4.

Flavobacterium columnare causes columnaris disease in wild and cultured freshwater fish and is a major problem for sustainable aquaculture worldwide. The F. columnare type IX secretion system (T9SS) secretes many proteins and is required for virulence.