An alternative molecular approach for rapid and specific detection of clinically relevant bacteria causing prosthetic joint infections with bacteriophage K.

Prosthetic joint infections (PJI) represent the most serious cause of prosthetic joint loosening, with high impact on patient life and health economics. Although not entirely reliable, the cultivation of intraoperative prosthetic tissue or synovial fluid remains the gold standard for determining the cause of PJI. Therefore, molecular methods are increasingly being introduced. The aim of this study was to optimize and assess an alternative molecular approach with the use of bacteriophage K for more rapid and specific detection of staphylococci in sonicate fluid (SF) of PJI. The best results with the method were obtained after 180 min of sample incubation with 104 PFU/mL of bacteriophage K. DNA isolation prior to qPCR analysis was confirmed unnecessary, while chloroform addition to samples after incubation with bacteriophage K improved bacterial detection by 100×. The method had a limit of detection of 6.8×102 CFU/mL and was found suitable for the detection of staphylococci in SF of removed prosthetic joints, giving results comparable to standard microbiological methods in just four hours. The optimized method was found fit for the purpose, offering potential advantages over the use of molecular detection methods to detect bacterial DNA.