Emergence of <i>Staphylococcus argenteus</i> in pediatrics: Molecular insights from a hospital in East China

<i>Staphylococcus argenteus</i> is a novel species within the <i>Staphylococcus aureus</i> complex and can cause serious bloodstream infections (BSIs) in humans, which have been mainly reported in adults, especially the elderly. In this study, we analyzed the molecular characterization of a strain of <i>S. argenteus</i> (22WJ8192) isolated from the peripheral vein blood sample of a seven-month-old female infant in Eastern China. The 22WJ8192 belonged to sequence type (ST)2250 and harbored six antibiotic-resistance genes and 53 virulence genes and was resistant to penicillin. Additionally, we conducted a comparative analysis of the molecular characteristics of <i>S. argenteus</i> sourced from various origins within the dataset, predominantly from the National Center for Biotechnology Information Collection (NCBI) genome database. Antibiotic-resistance genes <i>blaR1</i>, <i>blaI_of_Z</i>, <i>blaZ</i>, <i>fosB-Saur</i>, <i>tet(L)</i>, <i>aph(3")-IIIa</i>, <i>mecA</i>, and <i>dfrG</i> were more prevalent among the strains of human origin. Virulence genes <i>lukF-PV</i>, <i>sak</i>, <i>sdrE</i>, <i>scn</i>, <i>sdrC</i>, and <i>sdrD</i> were more prevalent among strains of human origin. The presence of antibiotic-resistance genes <i>blaR1</i>, <i>blaI_of_Z</i>, <i>blaZ</i>, <i>fosB-Saur</i>, and <i>aph(3")-IIIa</i> in strain 22WJ8192 was also more common among strains of human origin in the dataset. Conversely, the antibiotic-resistance genes <i>tet(L)</i>, <i>mecA</i>, and <i>dfrG</i>, typically found in strains of human origin, were not detected in 22WJ8192. Additionally, virulence genes <i>lukF-PV</i>, <i>sak</i>, <i>sdrE</i>, <i>scn</i>, <i>sdrC</i>, and <i>sdrD</i> present in 22WJ8192 exhibited a higher prevalence among strains of human origin in the dataset. In conclusion, this study emphasizes the potential of <i>S. argenteus</i> ST2250 to induce severe bloodstream infections in infants, shedding light on the molecular characteristics of this strain.