Haemophilus species


Gram-Negative Cocci & Coccobacilli   
>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: led
     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

Haemophilus species

  •  Gram-negative, pleomorphic (wide range of shapes), coccobacilli bacteria belonging to the Pasteurellaceae family.
  • All members are either aerobic or facultatively anaerobic. 
  • Significant pathogenic species include:
  • 1] H. influenzae: cause of sepsis and bacterial meningitis in young children and
  • 2] H. ducreyi, causative agent of chancroid.

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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. 

Haemophilus ducreyi:

  1. Azithromycin 1 gram po x 1.
  2. Ceftriaxone 250 mg IM x 1
  3. Ciprofloxacin 500 mg bid x 3 days
  4. Erythromycin 500 mg tid x 7 days

Haemophilus influenzae:

  1. Amoxicillin 500mg orally three times daily or Ampicillin 1-2 grams IV every 4-6 hours
  2. Augmentin 875/125 mg orally twice daily
  3. Ceftin (cefuroxime oral)  500mg orally twice daily
  4. Cefdinir (Omnicef) 300 mg po q12h or 600 mg po q24h
  5. Levofloxacin 500mg – 750 mg IV/PO once daily
  6. Moxifloxacin 400 mg IV/po once daily
  7. Azithromycin 500mg orally x 1 then 250mg  once daily for 4 days
  8. Clarithromycin 500mg po q12h 
  9. Cefotaxime 1-2 grams IV q4-12h.  Mild: 1 gram q12h.  Moderate to severe: 1-2 grams q8h.  Life-threatening: 2 grams IV q4h.
  10. Ceftriaxone 1-2 grams IV q24h  (range: 1-2 grams q12-24h)
  11. Telithromycin (Ketek®) – 800mg po once daily. [Renal: Crcl<30: 600mg qd (or 400mg qd if concomitant hepatic impairment))]


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