Five-decade global expansion of Staphylococcus argenteus ST2250 shapes antimicrobial resistance dynamics

Staphylococcus argenteus is implicated in various superficial and invasive diseases in humans, and multidrug resistance has been increasingly reported. Here, we aim to elucidate the bacterial features shaping the global spread of antimicrobial resistant S. argenteus. The global population contained a heterogeneous collection of antimicrobial resistance (AMR) genes, virulence genes and plasmid replicon types. Of the 13 sequence types (ST) present, ST2250 made up 56.2% of the dataset. We estimate its most recent common ancestor to have emerged in 1967. Two sublineages of ST2250 with distinct AMR gene content appeared separately in Asia and Europe in 1989 and 1992, respectively. The effective population size of ST2250 has soared in the past five decades, although there is indication of a recent decline. Overall, our results show that the AMR pool of S. argenteus is driven in part by the clonal expansion and subsequent diversification of ST2250 worldwide.