Decoding resistance: a comprehensive study on pathogens and antibiotic efficacy in periprosthetic joint infections.

Abstract

Background: Periprosthetic joint infection (PJI) continues to be a severe complication following total joint arthroplasty (TJA). Identifying the causative pathogens and their antibiotic resistance profiles is essential for the effective eradication.

Materials and methods: In this retrospective study, 825 antibiograms and demographic data of patients with confirmed PJIs from 2005 to 2021 were evaluated. The resistance profile evaluation focused on the antibiotics ampicillin/sulbactam, clindamycin, gentamicin, vancomycin, ciprofloxacin and rifampicin.

Results: Methicillin-sensitive staphylococcus aureus (MSSA) was the most prevalent pathogen (20.8%) followed by methicillin-resistant staphylococcus epidermidis (MRSE, 16.1%) and methicillin-sensitive staphylococcus epidermidis (MSSE, 10.8%). Polymicrobial (PM) PJI (15.9%) was also high with MSSA (21.2%) as the most frequent pathogen followed by gram-negative (GN) pathogens (20.2%) and MRSE (18.3%). The overall resistance rate against ampicillin/sulbactam and clindamycin was 42.3% and 40%, respectively. Vancomycin showed low resistance rates of nearly 1% with higher rates in enterococci (4%). MSSA and MRSA exhibit high sensitivity rates against gentamicin (97.4% and 89.5%). Gentamicin resistance was high in staphylococcus epidermidis (43%) and particularly in MRSE (64.6%). Ciprofloxacin resistance was especially high among MRSA (81.3%) and MRSE (84.0%) isolates, whereas sensitivity was most common in GN (78.5%) and MSSE (85.0%) groups. This study reveals high rates of MRSE, SE and GN pathogens causing PJI. GN and MRSE rates were also increased in PM PJI. The high overall resistance rates against ampicillin/sulbactam raise doubts as first line empiric oral antibiotic in PJI. The nearly 20% ciprofloxacin resistant GN pathogens should be alarming due to limited choice of biofilm-penetrating antibiotics in GN PJI.