Coinfection of Fusobacterium nucleatum and Actinomyces israelii in Mastoiditis Diagnosed by Next-Generation DNA Sequencing

Some bacterial infections involve potentially complex mixtures of species that can now be distinguished using next-generation DNA sequencing. We present a case of mastoiditis where Gram stain, culture, and molecular diagnosis were nondiagnostic or discrepant. Next-generation sequencing implicated coinfection of Fusobacterium nucleatum and Actinomyces israelii , resolving these diagnostic discrepancies.