Clinical Scorecard: Chronic Osteomyelitis of the Fibula Associated with Schaalia turicensis: A Case Study and Review of Existing Literature

At a Glance

Key Highlights

• Chronic osteomyelitis may follow trauma or surgery and can involve persistent infection and progressive bone destruction.

• Meticulous acquisition of viable deep-tissue specimens from the site of infection is important for accurate pathogen identification.

• mNGS used alongside conventional culture can aid detection of fastidious, slow-growing, or culture-resistant pathogens.

• Beta-lactam antibiotics are described as the first treatment choice for actinomycosis.

• In the reported case, treatment was changed to oral clindamycin after culture identified Actinomyces species and methicillin-resistant Staphylococcus epidermidis (MRSE), followed by clinical improvement and discharge.

Guideline-Based Recommendations

Diagnosis

• Obtain viable deep-tissue specimens from the epicenter of infection rather than relying on superficial samples.

• Use conventional culture together with molecular diagnostics such as mNGS when evaluating chronic osteomyelitis, particularly when fastidious or slow-growing organisms are suspected.

Management

• Beta-lactam antibiotics are the first treatment choice for actinomycosis.

• Combine targeted antimicrobial therapy with appropriate surgical debridement in chronic osteomyelitis.

Monitoring & Follow-up

• The source does not specify a standardized monitoring protocol. In the reported case, clinical improvement was observed after surgical debridement and targeted antimicrobial therapy, and the patient was subsequently discharged.

Risks

• Actinomycotic osteomyelitis may be difficult to diagnose because of its insidious onset, nonspecific manifestations, and frequent polymicrobial presentation.

• Diagnostic delay ranged from 1 month to 16 years in the reviewed cases, and the authors note that amputation may become necessary in patients with delayed diagnosis and recurrent, expanding infection.

Patient & Prescribing Data

The reported patient was a 57-year-old woman with more than 4 years of recurrent redness, swelling, ulceration, and exudation of the left lower leg after a remote traumatic ankle fracture.

After mNGS identified S. turicensis, intravenous penicillin G at 4.8 million units every 6 hours was initiated. Conventional culture 6 days later identified Actinomyces species and MRSE, and therapy was changed to oral clindamycin 300 mg 4 times daily, followed by clinical improvement and discharge.

Clinical Best Practices

• Obtain deep-tissue specimens during surgical evaluation of chronic bone infection.

• Integrate mNGS, conventional culture, and histopathologic findings to support pathogen identification.

• Use targeted antimicrobial therapy together with adequate surgical debridement.

• Consider low-virulence or indolent pathogens when chronic wounds fail to respond as expected.

Related Resources & Content

• Gao Q, Liu Q, Zhang G, Lu Y, Li Y, Tang M, et al. “Identification of pathogen composition in a Chinese population with iatrogenic and native vertebral osteomyelitis by using mNGS.” Annals of Medicine. 2024;56:2337738.

• Ryu DJ, Jeon YS, Kwon HY, Choi SJ, Roh TH, Kim MK. “Actinomycotic osteomyelitis of a long bone in an immunocompetent adult: a case report and literature review.” BMC Musculoskeletal Disorders. 2019;20:185.

• Lee MJ, Ha YE, Park HY, Lee JH, Lee YJ, Sung KS, et al. “Osteomyelitis of a long bone due to Fusobacterium nucleatum and Actinomyces meyeri in an immunocompetent adult: a case report and literature review.” BMC Infectious Diseases. 2012;12:161.

• Wang TKF, Tsang HF, Wong SCC, Leung SWM. “Cervical actinomycosis diagnosed via metagenomic next-generation sequencing of formalin-fixed paraffin-embedded tissue: a case report and literature review.” Microorganisms. 2025;13:1855.

• Könönen E, Wade WG. “Actinomyces and related organisms in human infections.” Clinical Microbiology Reviews. 2015;28:419–442.