Determination of the role of opportunistic microorganisms Staphylococcus spp., Streptococcus spp. and Enterobacteriaceae in the etiology of periprosthetic infection after endoprosthetics of large joints

Periprosthetic joint infection (PJI) is a serious complication of large joint arthoplasty, often necessitating repeated surgical interventions and prolonged antimicrobial therapy. Polymerase chain reaction (PCR) offers significant advantages in the aetiological diagnosis of PJI, namely rapid result acquisition and high sensitivity and specificity. This study aims to use real-time PCR to determine the role of Staphylococcus spp., Streptococcus spp., and Enterobacteriaceae as microbial aetiological agents of PJI, and to examine their presence in the biocenoses of the upper respiratory, urogenital, and gastrointestinal tracts in patients with PJI, in order to assess the potential role of opportunistic bacteria as endogenous risk factors for infection follo­wing large joint arthroplasty. The findings confirm that the detection of Staphylococcus spp., Streptococcus spp. and Enterobacteriaceae DNA in synovial fluid and synovial membrane fragments in patients with clinical signs of infection serves as a microbiological indicator of PJI. Furthermore, the microbial composition of the upper respiratory, urogenital and gastrointestinal biocenoses is analysed. A diagnostically significant criterion for identifying patients at risk of PJI is the detection of opportunistic microorganism DNA at concentrations of ≥1.0 × 10⁴ copies/ml in the study biotope, accompanied by clinical evidence of local inflammation.