Capnocytophaga canimorsus
From IDWiki
Background
Microbiology
- Gram-negative bacillus in the genus Capnocytophaga
- May be fusiform and curved
- Grows slowly on standard media
- Capnophilic, preferring high CO2
- Oral flora of dogs (60-70%) and cats (15-55%)
Risk Factors
- Risk factors for severe disease include asplenia and alcoholism
Clinical Manifestations
- Infections usually occur after penetrative inoculation from a dog bite or by exposure of membranes or wounds to saliva
- Exposures include close petting, kissing, minor scratches, licking of abrasions, licking of intact skin
Bacteremia
- Symptoms associated with bacteremia include fever, diarrhea, abdominal pain, vomiting, headache, and confusion
- A rash is present in 20 to 40%, which can vary from macular or maculopapular rash on trunk and extremities, to purpura fulminans
- Mortality with bacteremia is 15 to 30%
Meningitis
- Headache, fever, neck stiffness, and altered mental status
Other Sites
- Endocarditis is rare, but high mortality around 25%
- Case reports of brain abscess, spinal epidural abscess, eye infections, bone and joint infections, cellulitis, glomerulonephritis, and pneumonia
Management
- Highly susceptible to meropenem, imipenem, piperacillin-tazobactam, amoxicillin-clavulanic acid, and tigecycline
- May be susceptible to ciprofloxacin, clindamycin, erythromycin, tetracycline, aztreonam
- Often resistant to gentamicin, vancomycin, polymyxin B, trimethoprim, ceftazidime, cefotaxime, and amoxicillin
