Image Gallery: Actinomycetoma caused by Gordonia terrae in an immunocompetent woman

Gordonia sputi-associated bloodstream infection in a renal transplant patient with chronic indwelling central venous catheter: a case report and literature review

Introduction

Although rare, human infections caused by Gordonia spp. have been reported, especially within the immunocompromised population and those with long-term indwelling devices. We report a case of Gordonia spp. bacteraemia in a renal transplant patient and present a literature review on microbiological identification methods of this organism.

Case Presentation

A 62-year-old female renal transplant recipient admitted to hospital with a 2-month history of dry cough and fevers occurring weekly when receiving electrolyte replacement infusions via a Groshong line. Over 2 weeks, blood cultures repeatedly isolated a Gram-positive bacillus solely in aerobic bottles, and this was initially reported as Rhodococcus spp. by the local microbiology laboratory. Chest computed tomography (CT) showed multiple ground-glass lung opacities suggestive of septic pulmonary emboli. As central line-associated bloodstream infection was suspected, empirical antibiotics were initiated and the Groshong line was removed. The Gram-positive bacillus was later confirmed by the reference laboratory as Gordonia sputi via 16S rRNA sequencing. Vancomycin and ciprofloxacin for a duration of 6 weeks were completed as targeted antimicrobial therapy. After treatment, the patient remained symptom-free with marked improvement on repeat CT chest imaging.

Conclusion

This case illustrates the challenges surrounding identification of Gordonia spp. and other aerobic actinomycetes. 16S rRNA gene sequencing may be a preferred identification method, especially when initial workup of a weakly acid-fast organism fails to make an identification or shows discrepant results using traditional diagnostic modalities.

Mycetoma in China: A Case Report and Review of the Literature

Mycetoma is a chronic granulomatous infectious disease that can affect the skin, subcutaneous tissue, fascia and bone. It can be caused by filamentous bacteria or fungi and usually involves the legs and feet. Mycetoma is endemic in tropical and subtropical regions and is easily misdiagnosed in clinical practice because of its nonspecific clinical features and lack of awareness of the disease. Although mycetoma is very rare in mainland China, an increasing number of cases have been reported in recent years. Here, we report a case of mycetoma in a patient who was misdiagnosed many years before receiving the correct treatment, leading to disease progression and motion limitation. The grains that represent microorganismal colonies were important clues for diagnosis. We also reviewed reported cases of mycetoma in mainland China. The majority of cases were reported from southern regions. Actinomycetoma was more commonly reported than was eumycetoma. The causative agents of actinomycetoma included Nocardia brasiliensis, N. asteroides, N. otitidiscaviarum, N. ninae and Gordonia terrae, and the causative fungi of eumycetoma were identified as Madurella mycetomatis, Fonsecaea pedrosoi and Acremonium falciforme. Notably, the diagnosis of mycetoma was delayed from months to decades in all of the patients, likely due to a lack of clinical experience. Our literature review suggests the importance of increased awareness of mycetoma in clinical practice, especially in non-endemic regions. Further investigative studies are needed to determine the real incidence of the disease in China.