Community-Acquired Necrotizing Pneumonia Caused by ST72-SCCmec Type IV-Methicillin-Resistant Staphylococcus aureus in Korea
A 57-year-old woman who had previously been healthy except for a history of pulmonary tuberculosis thirty years ago and who was on current medication for hypertension and depressive episodes, was admitted to our hospital with high fever, cough and sputum for 3 days. On admission, dyspnea and chest pain developed. Chest CT showed multiple patchy consolidations in both lower lobes and the right middle lobe of the lung (). Laboratory tests revealed a leukocyte count of 1,820/µL, hemoglobin at 9.9 g/dL, and a platelet count of 192,000/µL. After 2 days, she rapidly deteriorated and was admitted to the intensive care unit (ICU) following intubation for severe hypoxemia. She was diagnosed with severe CAP and ceftriaxone and azithromycin were administrated empirically. While Gram stain of respiratory specimens revealed gram-positive cocci, the urinary antigen test for S. pneumoniae was negative. MRSA grew from sputum culture and the strain was susceptible to gentamicin, rifampicin, ciprofloxacin, trimethoprim/sulfamethoxazole, erythromycin and clindamycin. Vancomycin was added to the empiric treatment on hospital day 5. Due to the persistent fever following administration of vancomycin for 7 days, vancomycin was replaced with linezolid. Bilateral infiltration in the lungs with respiratory failure resulted in acute respiratory distress syndrome which was treated with adjunctive corticosteroid treatment. Ultimately, the patient recovered following linezolid treatment for 7 days in addition to vancomycin treatment for 7 days and corticosteroid treatment for 4 weeks. Typing of the MRSA isolate from the patient revealed that the isolate belonged to MLST ST72, carried SCCmec type IV and was negative for PVL.