Aggregatibacter actinomycetemcomitans (Aa): The Wrecking Ball

Aug 10, 2026 | Aa | Pink Complex Pathogen

Aggregatibacteractinomycetemcomitans (Aa) Pink Complex Pathogen

Meet Aa: The Wrecking Ball 🩷

Aggressive Disease Pathogen

Aggregatibacter actinomycetemcomitans is quite a name—so we’ll just call it Aa.

Think of Aa as “The Wrecking Ball.” This is a bacterium that gets our attention because it’s associated with more aggressive forms of periodontal disease and can contribute to rapid bone loss around teeth.

Aa produces toxins that can damage immune cells, making it easier for the infection to progress. And here’s something important to remember: Aa may be clinically significant even when it’s detected at lower levels. It’s also sometimes seen in younger patients with periodontal concerns.

Quick way to remember Aa:
🩷 Pink Complex
💥 The Wrecking Ball
🦷 Think aggressive disease + rapid bone loss
⚠️ Don’t automatically dismiss it just because the level is lower.

Seeing Aa on a MicrobeLinkDx report?

Your bacterial results are just one part of the clinical picture. Head over to Interpreting My Results for help understanding bacterial levels, complexes, and the rest of your report.

Interpreting My Results →

Aa Research & Updates

We’ll continue adding new research, clinical information, and resources about Aa

You may also like…

No Results Found

The page you requested could not be found. Try refining your search, or use the navigation above to locate the post.

The Latest

Who Should Be Tested with MicrobeLink Dx®? | 11-Microbes DNA-PCR Test

Who Should Be Tested with MicrobeLink Dx®? | 11-Microbes DNA-PCR Test

🦠 Not every patient needs bacterial testing… but the right ones do.With MicrobeLink Dx®, you can identify the patients most at risk—catching infection early and preventing bigger problems down the road. Who should be tested?✔️ Patients with bleeding gums (an early...

Capnocytophaga sp. (Cs): The Immune Watcher

Capnocytophaga sp. (Cs): The Immune Watcher

Meet Cs: The Immune Watcher 👀 Immune-Response Associated | Green Complex Capnocytophaga species — or Cs — can be present at low levels in the mouth, but the amount matters. Think of Cs as “The Immune Watcher.” Cs is associated with gum inflammation and may become more...

Eikenella corrodens (Ec): The Opportunist

Eikenella corrodens (Ec): The Opportunist

Meet Ec: The Opportunist 🦠 Opportunistic Pathogen | Green Complex Eikenella corrodens — or Ec — is a little different from some of the other bugs we've met. Think of Ec as “The Opportunist.” Ec is usually found alongside other bacteria and may become more significant...

Eubacterium nodatum (En): The Long-Hauler

Eubacterium nodatum (En): The Long-Hauler

Meet En: The Long-Hauler 🦠 Immune-Response Associated Pathogen | Yellow Complex Eubacterium nodatum — or simply En — is typically found in more advanced periodontal disease and often shows up alongside other high-risk bacteria. Think of En as “The Long-Hauler.” When...

Campylobacter rectus (Cr): The Persistent Mover

Campylobacter rectus (Cr): The Persistent Mover

Meet Cr: The Persistent Mover 🏃 Motile Periodontal Pathogen | Yellow Complex Campylobacter rectus — or Cr — is a motile periodontal pathogen associated with ongoing inflammation and disease progression. Think of Cr as “The Persistent Mover.” It's more commonly...