Successful treatment of Staphylococcus argenteus sequence type 2198 uncomplicated bacteremia with a 2-week antibiotic course

There is a paucity of data on the clinical course and treatment of <i>Staphylococcus argenteus</i>. Herein, we describe a successfully treated case of <i>S. argenteus</i> bacteremia. A 76-year-old man with lung adenocarcinoma developed bacteremia caused by penicillin-resistant, oxacillin-susceptible <i>S. argenteus</i>, which was identified through mass spectrometry and <i>nuc</i> gene sequencing. He was diagnosed with a peripheral line-associated bloodstream infection and successfully treated with a 2-week course of cefepime, followed by cefazolin, concurrent with intravenous catheter removal. The isolate was positive for <i>blaZ</i> and negative for <i>mecA</i>. It was assigned to sequence type 2198 using multilocus sequence typing. Formerly classified as <i>Staphylococcus aureus</i> clonal complex 75, <i>S. argenteus</i> became a distinct species in 2015. Its identification has increased owing to widespread mass spectrometer use. Most East and Southeast Asian <i>S. argenteus</i> isolates reported to date are methicillin-susceptible, consistent with the susceptibility pattern of the isolate in our study. Given the potential equivalence in virulence between <i>S. argenteus</i> and <i>S. aureus</i>, we recommend treating <i>S. argenteus</i> with the same rigor as <i>S. aureus</i> until further clinical data becomes available.