Clinical Microbiology and Antimicrobial Chemotherapy. 2025; 27(3):395-405
To assess impact of the COVID-19 pandemic on the structure of pathogens causing periprosthetic joint infection (PJI) and the dynamics of their antibiotic resistance.
A retrospective analysis of 379 strains of microorganisms isolated from patients with PJI of the knee and hip joints who underwent surgical treatment at the Federal Center for Traumatology and Orthopedics from 2018 to 2024 was performed. The biological material for the study was synovial fluid samples, tissue biopsies, aspirates from removed implants after ultrasonic treatment. Identification of the isolated pathogens and sensitivity to antibiotics were determined by the disk diffusion method and dilution methods on VITEC 2 compact or Multiscan FC analyzers in accordance with the EUCAST 2018, 2021, and 2024 criteria, depending on the year of study. Molecular methods were used to detect resistance genes.
The leading causative agents of PJI were gram-positive bacteria, the most common being CoNS in 27.7–46.7% and S. aureus in 23.4-33.0% of cases. In the post-COVID period, there was an increase in the frequency of gram-negative microorganisms from 6.5% to 14.9% (p = 0.0534) with a predominance of bacteria of the order Enterobacterales (p = 0.0242); an increase in the proportion of microbial associations from 4.3% to 11.8% (p = 0.0341) and the emergence of fungi. After the COVID-19 pandemic, an increase in methicillin-resistance was detected among coagulase-negative staphylococci (from 56.0% to 76.9%), the emergence of resistance to carbapenems and aztreonam among Enterobacterales and vancomycin among enterococci. Gram-positive bacteria were 100% sensitive to linezolid, and gramnegative bacteria were sensitive to colistin and tigecycline. Among the analyzed bacteria, high resistance to fluoroquinolones, co-trimoxazole and cefoxitin was detected (these drugs are not recommended for empirical therapy).
The impact of COVID-19 on the structure of PJI requires further study. Irrational use of antibiotics contributes to the emergence and growth of antibiotic resistance in pathogens of communityacquired infections and the development of the phenomenon of «parallel damage». This study highlights the need for continuous local monitoring of PJI pathogens and their antibiotic resistance to optimize treatment and prevention, including restrictive measures.