Molecular Characteristics, Virulence Gene and Wall Teichoic Acid Glycosyltransferase Profiles of Staphylococcus aureus: A Multicenter Study in China

Staphylococcus aureus (S. aureus) evolves constantly under host and environment pressures. The monitoring network is essential in assessing the epidemiology of S. aureus infections. A total of 555 S. aureus isolates were collected from five hospitals in three different geographical regions of China for the investigation of molecular characteristics, antibiotic resistance, virulence gene and wall teichoic acid (WTA) glycosyltransferase gene profiles. 233 (42.0%) isolates were identified as MRSA and 323 (58.2%) were defined as MDR isolates. MRSA prevalence showed no significant difference among three regions, whereas the MDR prevalence was significantly higher in central China than that in northern China (63.5% vs. 50.8%, P 0.05). The distribution of the pvl, etb, tsst, clfb, sdrD, hlg, fnbA and hla showed significant differences among different regions.We found five glycosylation patterns with tarP-/tarS+/tarM-/tagN- being the most combination. The β-1,3-GlcNAc glycosyltransferase gene tarP was not only identified in CC5 and CC398. All of 16 tarP-positive isolates also contained the tarS. In addition, tarS was present in almost all S. aureus isolates except 10 ST630 isolates. The tagN gene was only detected in 10 of 12 ST630 S. aureus isolates without tarS. The tarM gene was absent in CC5 and CC398. In brief, there were regional differences among molecular characteristics, antibiotic resistance and virulence gene profiles. The tarS-negative ST630 lineage carried the tagN, which was never found before, indicating that it was capable of expressing GroP-α-GalNAc WTA and exchanging mobile genetic elements with other species such as Staphylococcus epidermidis.