Emergence of teicoplanin-non-susceptible Staphylococcus epidermidis strains: a 6-year retrospective study

The use of glycopeptide antibiotics for the treatment of Staphylococcus epidermidis infections has recently increased owing to increased oxacillin resistance. This study aimed to characterize and evaluate the clinical significance of teicoplanin-resistant S. epidermidis isolated at our hospital over a 6-year period. During the study period, 328 strains of S. epidermidis were isolated, of which 17 (5.2%) were teicoplanin-non-susceptible. All strains were vancomycin-susceptible, and 292 (89%) were oxacillin resistant. Analysis of vancomycin and teicoplanin prescriptions revealed an increase in annual teicoplanin prescription in 2020. Although there was a decrease in glycopeptide antibiotic usage in 2020 and 2021 owing to the COVID-19 pandemic, there was a rapid increase in the number of of teicoplanin-non-susceptible S.epidermidis strains isolated in 2021 (13; 32.5%). These data suggest that extensive teicoplanin use may have induced S.epidermidis antibiotic resistance in the hospital setting through selective pressure. The incidence of S.epidermidis teicoplanin resistance has rapidly increased at our hospital due to increased teicoplanin use. The emergence of teicoplanin-non-susceptible S.epidermidis reduces available antibiotic options and increases the risk of treatment failure. The cause of the emergence of teicoplanin-non-susceptible S.epidermidis strains needs to be further analyzed and countermeasures need to be developed against this resistance.