Capnocytophaga canimorsus

MICROBIOLOGY

• C. canimorsus (previously known as DF-2, dysgonic fermenter) and C. cynodegmi (previously known as DF-2 like organism) are facultatively anaerobic gram-negative rod, part of normal oral flora of dogs and cats.
• C. cynodegmi is considered less virulent than C. canimorsus.
• Other Capnocytophaga species may be part of normal human oral flora or dental plaque, e.g., C. sputigena and C. gingivalis.

• Organisms have a long, fusiform appearance on gram stain, making it distinctive enough to consider morphologic identification pending cx results.
• Organisms considered fastidious by micro lab.
• Most strains are resistant to polymyxin, fusidic acid, fosfomycin and trimethoprim. Variably active: beta-lactams, erythromycin, quinolones, metronidazole, vancomycin, aminoglycosides. Usually active: beta-lactam/beta-lactamase inhibitors and carbapenems.