Detection of Staphylococcus argenteus in blood cultures

Abstract

Staphylococcus argenteus is a new species that was subclassified from Staphylococcus aureus in 2015, which is difficult to accurately identify by routine testing. Although invasive infections by S. argenteus have been sporadically reported, its detection rate and pathogenicity have not been fully elucidated. Therefore, we attempted to re-identify S. argenteus from the strains detected in blood culture and identified as methicillin-sensitive S. aureus at Kyorin University Hospital from 2016 to 2019, and analyzed toxin-producing genes and drug susceptibility of S. argenteus strains. Of the 312 strains tested, two (0.6%) were re-identified as S. argenteus. Both strains did not have toxin-producing genes and were susceptible to all antimicrobial agents except for penicillin. The detection rate of S. argenteus in blood cultures was lower than that reported in other countries. Further investigation is necessary to elucidate the prevalence and clinical significance of S. argenteus infections in Japan, and development of a simple method for species identification is essential.