Simultaneous intraoperative detection of methicillin-resistant Staphylococcus and pan-bacterial infection during revision surgery: use of simple DNA release by ultrasonication and real-time polymerase chain reaction.

BACKGROUND: Periprosthetic infection is one of the most serious complications of arthroplasty, and low-grade infections are particularly difficult to diagnose with use of conventional culture methods. Real-time polymerase chain reaction is a potentially viable way to overcome this detection problem as it is a more rapid and sensitive technique. In the current study, we used intraoperative polymerase chain reaction identification combined with a simple DNA-release method with ultrasonication to diagnose periprosthetic infections during revision surgery.
METHODS: Thirty revision arthroplasty procedures were included in this prospective study. Surgical specimens were obtained intraoperatively, treated with ultrasonication, and then analyzed with real-time polymerase chain reaction. Methicillin-resistant Staphylococcus-specific polymerase chain reaction and 16S rRNA gene universal polymerase chain reaction were performed simultaneously to facilitate both specific and broad-range detection. Specimens obtained from the same sites were also analyzed with microbiologic culture and histopathological evaluation.
RESULTS: The specific polymerase chain reaction revealed methicillin-resistant Staphylococcus infection in specimens from six of the thirty operations analyzed in the present study, and the 16S rRNA gene universal polymerase chain reaction analysis was positive for specimens from thirteen operations. Conventional cultures revealed six methicillin-resistant Staphylococcus infections, two Staphylococcus aureus infections, one infection with another Staphylococcus species, and two Streptococcus infections. The sensitivity of the polymerase chain reaction method was 0.87 and the specificity was 0.8 when compared with the combined results of microbiologic culture and histopathological evaluation.
CONCLUSIONS: The ultrasonication method that we developed for accelerated DNA sample preparation as a replacement for conventional extraction made possible the potential intraoperative identification of periprosthetic infection during revision surgery. The simultaneous detection of methicillin-resistant Staphylococcus and broad-range bacterial infections would be invaluable for the informed selection of antibiotics and also for the formulation of the subsequent treatment strategy (a one-stage or two-stage revision) for the patient.