{Reference Type}: Case Reports {Title}: Relapsing bronchopneumonia due to community-associated methicillin-resistant Staphylococcus aureus: a case report. {Author}: Shimada S;Yamaguchi T;Mikoshiba S;Sato K;Mitsumura T;Komori K;Yamana T;Iijima Y;Sakakibara R;Shibata S;Honda T;Shirai T;Okamoto T;Furusawa H;Tateishi T;Miyazaki Y; {Journal}: BMC Infect Dis {Volume}: 24 {Issue}: 1 {Year}: 2024 Apr 4 {Factor}: 3.667 {DOI}: 10.1186/s12879-024-09268-2 {Abstract}: BACKGROUND: The emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has increased the incidence of community-onset MRSA infection. Respiratory tract infections caused by MRSA has been noted for their severity; however, repeated relapses that require extended antibiotic therapy are rare.
METHODS: We report a case of relapsing bronchopneumonia caused by CA-MRSA in a 56-year-old man. The patient responded to antibiotics, but repeatedly relapsed after stopping treatment. MRSA was consistently isolated from airway specimens during each relapse. Extended oral antibiotic treatment with trimethoprim/sulfamethoxazole (TMP/SMX) for 6 months achieved infection control. Whole-genome sequencing of the isolated strain revealed that the causative agent was sequence type (ST)1/staphylococcal cassette chromosome mec (SCCmec) type IVa, a clone that is rapidly increasing in Japan.
CONCLUSIONS: This patient had an unusual course of MRSA bronchopneumonia with repeated relapses. Although the choice of antibiotics for long-term use in MRSA respiratory tract infections has not been well established, TMP/SMX was effective and well tolerated for long-term therapy in this case. The clinical course of infections related to the rapid emerging clone, ST1/SCCmec type IVa warrants further attention.