Post-influenza pneumonia caused by the USA300 community-associated methicillin-resistant Staphylococcus aureus in Korea

Abstract

Panton-Valentine leukocidin (PVL)-positive USA300 clone has been the most successful community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clone spreading in North America. In contrast, PVL-negative ST72-CA-MRSA has been predominant in Korea, and there has been no report of infections by the USA300 strain except only one case report of perianal infection. Here, we describe the first case of pneumonia caused by the USA300 strain following pandemic influenza A (H1N1) in Korea. A 50-year-old man was admitted with fever and cough and chest radiograph showed pneumonic consolidation at the right lower lung zone. He received a ventilator support because of respiratory failure. PCR for pandemic influenza A (H1N1) in nasopharyngeal swab was positive, and culture of sputum and endotracheal aspirate grew MRSA. Typing of the isolate revealed that it was PVL-positive, ST 8-MRSA-SCCmec type IV. The analysis of the PFGE patterns showed that this isolate was the same pulsotype as the USA300 strain.

Keywords: Influenza, Human; Methicillin-Resistant Staphylococcus aureus; Pneumonia.

Fig. 1

Chest computerized tomography (CT) scan shows a dense consolidation and necrotizing areas of the right lower lobe.

Fig. 2

Pulsed-field gel electrophoresis (PFGE) patterns of MRSA isolate from the patient and control strains obtained from the Network on Antimicrobial Resistance in Staphylococcus aureus (NARSA). PFGE was performed with restriction enzyme SmaI. Lane 1, isolate from the patient; lane 2, NRS384 (USA300); lane 3, NRS123 (USA400); lane 4, NRS385 (USA500); lane 5, NRS386 (USA700); lane 6, NRS387 (USA800); lane 7, NRS483 (USA1000); lane 8, NRS484 (USA1100); M, lambda marker.