Time line of the discovery of the species belonging to the genus Staphylococcus. Time line of the discovery of the species belonging to the genus Staphylococcus. Coagulase-negative species are shown in blue; coagulase-positive and coagulase-variable species are shown in red (note that only S. schleiferi subsp. coagulans is coagulase positive). Note that at the times of establishment of the first three species designations, S. aureus, S. epidermidis, and S. saprophyticus, these terms comprised a broader content than that accepted today. In particular, S. epidermidis and S. saprophyticus were used to describe nonpathogenic, saprophytic staphylococci (and other Gram-positive cocci occurring in clusters). Karsten Becker et al. Clin. Microbiol. Rev. 2014; doi:10.1128/CMR.00109-13