First Case of Actinomycetoma Caused by Gordonia rubripertincta

Abstract

Introduction: Mycetoma is a rare chronic infectious disease typically caused by bacteria or fungi, most commonly localized and affecting the skin, deep tissues and bones. In this case, mycetoma involving bone is presented in an immunocompetent patient. To our knowledge, this is the first case of actinomycetoma caused by Gordonia rubripertincta. Mehods & Results: We present the case of a 25-year-old male who complained of severe pain and deformation in his left foot. He reported that the symptoms began five years ago when he stepped on a wire. The patient underwent surgery, including incision, which initially improved his condition. However, the pain recurred, and the affected area expanded, leading to progression of pain and deformation. Skin biopsies were performed, and treatment with doxycycline was initiated but proved ineffective. Subsequently, the patient was diagnosed with actinomycetoma, and Gordonia rubripertincta was identified in culture. Treatment with amoxicillin-clavulanate initially improved the condition, but disease worsening was observed during follow-up. Long-term penicillin treatment was prescribed, and surgical excision was performed due to negative dynamics on radiological tests. Despite these efforts, symptoms continued to progress, prompting a bone biopsy after at least a 2-week antibiotic-free interval, which yielded no microorganism growth. Treatment with ampicillin-sulbactam and ciprofloxacin was initiated for at least six weeks, with offloading. Pain decreased, and radiological findings remained stable. Conclusion: Due to the rarity of cases, there is no universally established treatment protocol for Gordonia infections. While mycetoma is more common in tropical regions, this clinical case highlights the challenges in diagnosing and treating this rare disease.