Corynebacterium species

Corynebacterium species

Background:
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Gram-positive bacilli
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>Corynebacterium species:
     1] Corynebacterium diphtheria
     2] Corynebacterium jeikeium
     3] Corynebacterium urealyticum

Corynebacterium: 

  • Gram-positive, catalase positive, nonspore-forming, nonmotile, rod-shaped bacteria.
  • Aerobic or facultatively anaerobic.
  • Chemoorganotrophs: 51 – 65% genomic G:C content.
  • Widely distributed in nature and are mostly innocuous.
  • C. diphtheriae: pathogen responsible for diphtheria.
  • Pleomorphic through their life cycles: occur in various lengths and frequently have thickenings at either end, depending on the surrounding conditions.

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Therapy:
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.   Note: antibiotic therapy and diphtheria antitoxin for severe cases.

Corynebacterium diphtheria:

  1. Erythromycin 500 mg four times daily for 14 days
  2. Penicillin G (25,000 to 50,000 units/kg to a max of 1.2 million units IV q12h until patient can take oral medicine), then Penicillin VK 250 – 500mg orally q6h.   Total treatment course – 14 days
  3. Usually susceptible to multiple other agents:
  4. Clarithromycin 500mg po q12h
  5. Bactrim DS (TMP-SMX) 160/800mg po bid
  6. Ciprofloxacin 250-500 mg orally or 200-400mg IV  q12h.
  7. Vancomycin 1 gram  ivpb q12h (patient-specific dosing required)
  8. Daptomycin 4 – 6 mg/kg IV once daily.  NOT FOR PNEUMONIA
  9. Linezolid 600 mg orally or IV q12h

Corynebacterium jeikeium:  Resistant to many antibiotics, including penicillins, cephalosporins, and aminoglycosides

  1. Vancomycin 1 gram  ivpb q12h (patient-specific dosing required) +/- antipseudomonal aminoglycoside
  2. Daptomycin 4 – 6 mg/kg IV once daily.    – NOT FOR PNEUMONIA
  3. Linezolid 600 mg orally or IV q12h
  4. Tigecycline 100 mg IV x 1, then 50 mg q12h

Corynebacterium urealyticum:  resistant to Beta-lactams, aminoglycosides, and trimethoprim-sulfamethoxazole

  1. Vancomycin 1 gram  ivpb q12h (patient-specific dosing required)
  2. Linezolid 600 mg orally or IV q12h
  3. Daptomycin 4 – 6 mg/kg IV once daily.  NOT FOR PNEUMONIA
  4. Tigecycline 100 mg IV x 1, then 50 mg q12h
Corynebacterium species