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

Abstract

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.

Keywords: 16S rRNA; Actinomycetes; Gordonia; central line-associated bloodstream infection.

Fig. 1.

Chest computed tomography (CT) findings with contrast axial views. Yellow arrows: new ground-glass changes, anterior left upper lobe (a); solid to ground-glass opacity, posterior left upper lobe (b); subpleural ground-glass changes, anterior right lower lobe (c).

Fig. 2.

Colony morphology on sheep blood agar plate post-incubation. Beige non-haemolytic colonies, sheep blood agar, 115 h of incubation, 35±2 °C.

Fig. 3.

Gram stain of blood culture sample. Demonstration of Gram-positive coccobacilli under light microscopy, 100×.