Aggregatibacter species

Aggregatibacter species is a topic covered in the Johns Hopkins ABX Guide.

To view the entire topic, please or .

Pediatrics Central™ is an all-in-one application that puts valuable medical information, via your mobile device or the web, in the hands of clinicians treating infants, children, and adolescents. Explore these free sample topics:

-- The first section of this topic is shown below --

MICROBIOLOGY

  • Aggregatibacter spp. are normal residents of human oropharyngeal flora (especially dental plaques and gingiva), sometimes urogenital flora.
    • Member of Pasteurellaceae family.
  • Aggregatibacter actinomycetemcomitans (Aa) is a facultative Gram-negative, slowly growing coccobacillus.
    • Formerly known as Actinobacillus actinomycetemcomitans, a member of the HACEK group.
      • Earlier literature called the organism Haemophilus actinomycetemcomitans.
    • Original name due to descriptions of infections with actinomycotic-like presentations.
      • When isolated in an abscess, almost always found in conjunction with Actinomyces spp.
    • Generally easily isolated, but a slow grower and may need > 7d incubation.
    • The most common cause of Aggregatibacter endocarditis.
  • A. aphrophilus: formerly Haemophilus aphrophilus [Fig], is the second most common cause of Aggregatibacter endocarditis.
  • A. paraphrophilus: formerly Haemophilus paraphrophilus, a less common cause of endocarditis of this species (usually mitral valve), may also cause brain abscess.
    • Also found in the GI tract.
  • A. segnis: uncommon commensal in the oropharynx, a rare cause of endocarditis, bacteremia.
  • A. urae: meningitis reported.

-- To view the remaining sections of this topic, please or --

MICROBIOLOGY

  • Aggregatibacter spp. are normal residents of human oropharyngeal flora (especially dental plaques and gingiva), sometimes urogenital flora.
    • Member of Pasteurellaceae family.
  • Aggregatibacter actinomycetemcomitans (Aa) is a facultative Gram-negative, slowly growing coccobacillus.
    • Formerly known as Actinobacillus actinomycetemcomitans, a member of the HACEK group.
      • Earlier literature called the organism Haemophilus actinomycetemcomitans.
    • Original name due to descriptions of infections with actinomycotic-like presentations.
      • When isolated in an abscess, almost always found in conjunction with Actinomyces spp.
    • Generally easily isolated, but a slow grower and may need > 7d incubation.
    • The most common cause of Aggregatibacter endocarditis.
  • A. aphrophilus: formerly Haemophilus aphrophilus [Fig], is the second most common cause of Aggregatibacter endocarditis.
  • A. paraphrophilus: formerly Haemophilus paraphrophilus, a less common cause of endocarditis of this species (usually mitral valve), may also cause brain abscess.
    • Also found in the GI tract.
  • A. segnis: uncommon commensal in the oropharynx, a rare cause of endocarditis, bacteremia.
  • A. urae: meningitis reported.

There's more to see -- the rest of this topic is available only to subscribers.

Last updated: February 16, 2023