Columnaris
Columnaris ( also referred to as cottonmouth ) is a symptom of disease in fish which results from an infection caused by the Gram-negative , aerobic , rod-shaped bacterium "Flavobacterium columnare" . 
<triplet> Columnaris <subj> infection <obj> has cause <triplet> Gram-negative <subj> bacterium <obj> subclass of <triplet> Flavobacterium columnare <subj> Gram-negative <obj> Gram staining