Table 3.
Pathogens identified in a cohort of 47 adults with a diagnosis of brain abscess.
| Causative Organism | Number of cases (%) | Ceftriaxone Sensitivity |
|---|---|---|
| Gram positive infections | ||
| Streptococcus intermediusa,b | 20 (43%) | 20/20 (100%) |
| Streptococcus constellatusa,b | 4 (9%) | 4/4 (100%) |
| Streptococcus anginosisa | 4 (8.5%) | 4/4 (100%) |
| Streptococcus milleri group (not further identified)c | 1 (17.0%) | 1/1 (100%) |
| Staphylococcus aureusd | 1 (2.1%) | 1/1 (100%) |
| Listeria monocytogenese | 2 (4.3%) | 0/2 (0%) |
| Gram negative or mixed infections | ||
| E. coli + Staphlyococcus epidermidis | 1 (2.1%) | 1/1 (100%) |
| Pseudomonas aeruginosa | 1 (2.1%) | 0/1 (0%) |
| Fusobacterium nucleatumf | 3 (6.4%) | N/A |
| Citrobacter, Pseudomonas, Corynebacterium + anaerobes | 1 (2.1%) | 0/1 (0%) |
| Aggregatibacter aphrophilus + Actinomyces meyeri | 1 (2.1%) | 1/1 (100%) |
| No organism identified | ||
| Sterile sample | 4 (8.5%) | N/A |
| No sample taken | 4 (8.5%) | N/A |
a
These organisms are all part of the S. milleri group.
b
One S. intermedius and one S. constellatus reported in mixed culture with anaerobes.
c
Isolate grown from an orbital swab.
d
S. aureus sensitive to meticillin.
e
Both patients with Listeria infection were >55 years of age but neither had any known cause of immunosuppression.
f
Of the three cases with anaerobes isolated as a sole causative organism, two patients were intravenous drug users and the third had no clear identified source.