- Fastidious bacteria that can cause infective endocarditis (3% of native valve infections)
- Normal human oral flora
Species
- Haemophilus parainfluenzae and, rarely, Haemophilus influenzae
- Aggregatibacter actinomycetemcomitans and Aggregatibacter aphrophilus (two most common causes within the HACEK group)
- Cardiobacterium hominis
- Eikenella corrodens
- Kingella kingae
