The objective was to compare susceptibility testing of all coagulase negative species (CNS) found in periprosthetic joint infections (PJI).

We conducted a multicentre retrospective study in a same area from 2011 to 2014, including 215 CNS strains.

Diagnosis of PJI was based on clinical, radiological and biological criteria. Microbiological criterion was at least 2 per-operative deep positive cultures with the same species of CNS. Identification and susceptibility testing were performed on automated Vitek2 (Biomérieux, France).

PJI localizations were 54% knees, 39% hips, 7% other sites.

CNS found in our study were by dicreasing order:

S. epidermidis (SE) 60%, S. capitis 11%, S. lugdunensis (SL) 10%, S. caprae 5%, S. warneri (SW) 4%, S. hominis (SHo) 3%, S. haemolyticus (SHa) 3%. Fifty two percent of CNS strains were meticillin (oxacillin) resistant and 31%, 33%, 41%, 20% were also resistant to clindamycin (CLI), trimethoprim-sulfamethoxazole (SXT), ofloxacin (OFX), rifampicin (RMP) respectively. Regarding CNS species, meticillin resistance was detected for 70% SE, 71% SHo and 71% SHa. SE was the most resistant species, with 34% of the strains resistant to CLI, SXT, OFX and RMP simultaneously. Half of SE and SHa were resistant to the reference treatment levofloxacin+rifampicin. Thirteen percent of CNS were resistant to teicoplanin and only 1% to vancomycin.

Susceptibility testing profiles are presented in table field.

In our study, S. epidermidis was the main species found in PJI. Emerging species like S. lugdunensis or S. caprae were found, with more susceptible antibiotic profiles. The most active antibiotics in vitro were daptomycin, linezolid, vancomycin and teicoplanin.