Helcococcus kunzii, a skin-colonising microorganism with pathogenic capacity: a case of polymicrobial intracranial empyema

Helcococcus kunzii is a Gram-positive anaerobic facultative coccus that colonises the skin. Human infection is rare, with very few cases being described in the literature. The authors present the case of a 17-year-old man, with a history of cholesteatoma, diagnosed with mastoiditis complicated by intracranial empyema. After urgent surgical drainage, Gram staining revealed a Gram-negative bacillus and a Gram-positive coccus. The latter exhibited fastidious growth, presented as small grey colonies in blood agar, and was afterwards identified as H. kunzii. The patient was started on intravenous antibiotics, switched to oral route after 8 weeks and fully recovered. To the best of our knowledge, this is the third case of an intracranial infection in which H. kunzii is involved, two of them occurring in patients with cholesteatoma.