Chronic fibular osteomyelitis caused by Schaalia turicensis: A case report and literature review

Schaalia turicensis (previously classified as Actinomyces turicensis) may lead to actinomycosis, typically presented as a chronic, granulomatous infection marked by suppuration and sinus tract formation, with a propensity for recurrence. This report details a rare case of chronic post-traumatic osteomyelitis attributable to S. turicensis.

A 57-year-old woman was presented with a 4-year history of recurrent redness, swelling, and ulceration of the left lower leg after surgical intervention. Debridement of the lesion was performed by orthopedists. Metagenomic next-generation sequencing (mNGS) analysis of intraoperative tissue samples revealed S. turicensis, and penicillin therapy was initiated accordingly. Subsequent culture results identified Actinomyces species and methicillin-resistant Staphylococcus epidermidis. The antibiotic regimen was adjusted to clindamycin, leading to clinical improvement and eventual discharge.

This case underscores the diagnostic dilemma posed by indolent pathogens like S. turicensis in chronic postsurgical osteomyelitis. mNGS provided a rapid and precise microbiological diagnosis, directly informing critical therapeutic decisions.