Innumerable Culture-Negative Intracranial Abscesses in an Immunocompetent Young Male Diagnosed by 16s rRNA Gene Sequencing.

Here, we present a case of a healthy young man with an initial presentation concerning for infectious encephalitis later found on neuroimaging to have extensive intracranial lesions. Pathological analysis of these lesions was consistent with a bacterial intraparenchymal abscess; however, cultures were negative for a causative organism. Results of gene sequencing from an abscess sample were consistent with Streptococcus intermedius infection. Streptococcus intermedius, a β-hemolytic gram-positive species of the Streptococcus anginosus group (SAG), is known to possess several virulence factors that promote abscess formation.