| Age group | Most common bacteria |
| <3 months | Staphylococcus aureus (MSSA and MRSA) |
| Group B Streptococcus (Streptococcus agalactiae) | |
| Gram-negative bacilli | |
| Neisseria gonorrhoeae | |
| 3 months to 3 years | S. aureus (MSSA and MRSA) |
| Kingella kingae | |
| Group A Streptococcus (Streptococcus pyogenes) | |
| Streptococcus pneumoniae | |
| Haemophilus influenzae type b (Hib) (in incompletely immunized children in regions with low Hib immunization rates) | |
| >3 years | S. aureus (MSSA and MRSA) |
| Group A Streptococcus | |
| S. pneumoniae | |
| N. gonorrhoeae (in sexually active adolescents) |
