Biofilm formation is associated with poor outcome in prosthetic joint infections caused by .

BACKGROUND

has been described as a pathogen of increasing importance in prosthetic joint infections (PJI). Our aim was to describe the clinical presentation of PJI caused by , and to correlate the biofilm-forming ability of the bacterial isolates to clinical outcome.

METHOD

isolates from PJI episodes during 2015-2019 were included and analysed for biofilm formation using a microtiter plate assay. Medical records from the corresponding patients were reviewed.

RESULTS

We identified 36 patients with PJI caused by during the study period. Early postoperative PJIs were most frequent ( = 20, 56%). Surgical intervention was performed in a majority of the patients ( = 33, 92%), and the dominating type of antibiotic treatment was a combination of rifampicin and ciprofloxacin ( = 27, 75%). The treatment success-rate was 81% ( = 29). All isolates causing PJI were able to form biofilm . Biofilm formation was significantly stronger in isolates causing relapsing vs non-relapsing PJI (mean OD 3.1 ± 0.23 vs 1.14 ± 0.73  = .001) and strong biofilm formation was also associated with late acute hematogenic PJI (mean OD 1.8 ± 0.93 vs. 0.93 ± 0.81,  = .01).

CONCLUSION

Strong biofilm production in isolates was associated with relapse in PJI.