Eikenella Corrodens

Eikenella corrodens

Background:

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Gram-Negative Cocci & Coccobacilli
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>Aggregatibacter aphrophilus (formally known as Haemophilus aphrophilus)
>Bordetella pertussis (Causative agent of pertussis or whooping cough. )
>Brucella species:
     1] Brucella abortus
     2] Brucella canis
     3] Brucella melitensis
     4] Brucella suis
>Eikenella corrodens

>Haemophilus species:
     1] Haemophilus influenzae
     2] Haemophilus ducreyi
     3] Haemophilus avium
>Moraxella catarrhalis (formerly known as Branhamella catarrhalis)
>Neisseria species: (frequently colonize mucosal surfaces.)
     1] Neisseria gonorrhoeae
     2] Neisseria meningitidis
>Pasteurella multocida

Eikenella corrodens:

Fastidious, Gram-negative facultative anaerobic bacillus. Oxidase-positive, catalase-negative, urease-negative, and indole-negative, and reduce nitrate to nitrite.
Pleomorphic bacillus that sometimes appears coccobacillary and typically creates a depression (or “pit”) in the agar on which it is growing. It grows in aerobic and anaerobic conditions, but requires an atmosphere enhanced by 3-10% carbon dioxide.
Colonies are small and greyish, they produce a greenish discoloration of the underlying agar, and smell faintly of bleach (hypochlorite).
E. corrodens is a commensal of the human mouth and upper respiratory tract. It is an unusual cause of infection and when it is cultured, it is most usually found mixed with other organisms.
Infections most commonly occur in patients with cancers of the head and neck, but it is also common in human bite infections.
It is one of the HACEK group of infections which are a cause of culture-negative endocarditis.

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.

Augmentin 875/125 mg orally twice daily or 500/125mg three times daily or
Ampicillin-sulbactam (Unasyn) 1.5 – 3.0 grams IV q6h
Ceftriaxone 1-2 grams IV q24h
Ciprofloxacin 500-750 mg orally q12h or 400mg IV q12h (Severe/complicated: 400mg IV q8h)
Levofloxacin 500mg – 750 mg IV/PO once daily