Lobar pneumonia caused by Ralstonia pickettii in a sixty-five-year-old Han Chinese man: a case report

INTRODUCTION: Ralstonia pickettii is a gram-negative, oxidase-positive bacillus and is an emerging pathogen found in infections described in hospital settings. The cases reported in the literature mostly are nosocomial infections due to contaminated blood products, sterile water, saline, treatment fluids and venous catheters. Human infection unrelated to contaminated solutions is rare. We report a case of lobar pneumonia and pulmonary abscess caused by Ralstonia pickettii in an older patient. CASE PRESENTATION: A sixty-five-year old Han Chinese man presented having had cough, expectoration, chest pain and fever lasting for twenty days. His medical history was notable for hypertension over the previous ten years, and the habit of smoking for forty years. A thoracic computed tomography scan supported the diagnosis of right-sided lobar pneumonia. A lung biopsy was done and pathological analysis confirmed lobar pneumonia. Two lung biopsy specimens from separate sites grew Ralstonia pickettii. After six days, a repeat thoracic scan revealed a right-sided abscess. A thoracentesis was performed and the purulent fluid grew Ralstonia pickettii. The chest tube remained inserted to rinse the cavity with sterile sodium chloride. He received an antibiotic course of intravenous cefoperazone sodium-sulbactam sodium for eighteen days and imipenem-cilastatin for twelve days. A repeat chest X-ray revealed resolution of the pulmonary abscess and improvement of pneumonia. He remained afebrile and free of respiratory symptoms after treatments. CONCLUSION: This case demonstrates a Ralstonia pickettii infection in the absence of an obvious nosocomial source. It is possible that such cases will become common in the future. Therefore, further studies are needed to evaluate its sensitivity to common antibiotics.