Gram-negative bacteria. High degree of polymorphism. Commensal species that is considered an opportunistic pathogen.
Capnocytophaga are capnophilic bacteria, they can live only in environments where the concentration of carbon dioxide is greater than that of the atmosphere.
Capnocytophaga are fusiform Gram negative bacilli, and are part of the oral commensal flora (often isolated from periodontal pockets but also from apical and periodontal abscesses).
Includes 8 different species: Capnocytophaga ochracea, Capnocytophaga gingivalis, Capnocytophaga granulosa, Capnocytophaga haemolytica, Capnocytophaga sputigena, Capnocytophaga leadbetteri (isolated oral cavity of humans) and Capnocytophaga canimorsus and Capnocytophaga cynodegmi (isolated from the oral cavity of animals).
Normally found in the oropharyngeal tract of mammals, they are involved in the pathogenesis of some animal bite wounds as well as periodontal diseases.
Capnocytophaga canimorsus transmission following a dog bite can cause overwhelming sepsis in asplenic patients, the elderly, and the immunocompromised.
Empiric treatment for this bacteria following a dog bite, consisting of a third-generation cephalosporins early in the infection, should be instituted in these patient populations, or following deep bites or dog bites to the hand.
Important considerations: The choice of an agent should be based on local antimicrobial sensitivities, site of infection, cost, and comorbid conditions. Generally, the most common agents/regimens are listed first. Listed dosages may need to be adjusted for renal dysfunction.