Article in Japanese

Severe pulmonary pyogenesis caused by Panton-Valentine leucocidin positive community-acquired methicillin-resistant Staphylococcus aureus in a pediatric patient：A case report

Nanako OSHIMA^1）, Saho SHIMA^1）, Atsushi MIYAKE^1）, Yuhei TANAKA^1）, Kenji GOTOH^1）

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) primarily causes skin and soft tissue infections in healthy pediatric individuals and young adults. Panton-Valentine leucocidin (PVL), a cytotoxin produced by some strains of CA-MRSA, is known to be associated with the severity of CA-MRSA infections. We present a severe case of pulmonary pyogenesis caused by CA-MRSA carrying the PVL gene. The patient, a previously healthy two-year-old girl, presented to the emergency department with fever, cough, and impaired consciousness. She developed shock after 24 hours and was admitted to our hospital. Her illness was diagnosed as pulmonary pyogenic disease with pleural effusion and associated septic shock. Teicoplanin treatment was initiated with tazobactam/piperacillin. MRSA was detected in the pleural fluid. After 4 weeks of anti-MRSA therapy, computed tomography showed almost complete resolution of the pyogenesis. Oral sulfamethoxazole-trimethoprim antibiotics were continued for a further two weeks. Strain analysis revealed SCCmec type IVa, ST8, PVL-positive, and γ-hemolysin- positive CA-MRSA, which was found to be associated with TSST-1. Recently, PVL-positive CA-MRSA infections has been increasing in Japan. This case was considered severe due to the high toxicity of the pathogen. Therefore, we highlight the need for high suspicion of CA-MRSA in severe cases, and early initiation of anti-MRSA therapy needs to be considered.

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1）Department of Pediatrics and Child Health, Kurume University School of Medicine

Key words	pulmonary pyogenesis, septic shock, PVL, CA-MRSA
Received	July 28, 2023
Accepted	March 9, 2024

36 (2)：145─152,2024