INTRODUCTION: Rapid identification of bacteria species is essential for selecting of appropriate antibiotics in pyogenic spondylitis cases. However, the rapidness and sensitivity of conventional method is still insufficient in many clinical situations. Realtime polymerase chain reaction (PCR) has been recognized as an alternative tool for diagnosis of bacterial infection, which enables both rapid and sensitive detection and quantification. The purpose of this study was to evaluate the clinical usefulness of this method in the diagnosis of pyogenic spondylitis.
METHODS: A total of 26 patients with spinal disease including pyogenic spondylitis were enrolled consecutively. LightCycler system (Roche diagnostics) was used for real‐time PCR. Methicillin‐resistant staphylococcus‐specific PCR (MRS‐PCR) and 16s rRNA gene universal PCR(Universal PCR) were perfomed simultaneously. Specimens were also analyzed with microbiologic culture and histopathological evaluation.
RESULTS: Eight cases showed positive result with bacterial culture. With Universal PCR, gram‐positive bacteria were confirmed in seven cases, and gram‐negative bacteria were confirmed in six cases. Four cases were found to be positive with MRSPCR. The sensitivity of real‐time PCR was 100%, and the specificity was 72.2%. In all of the false‐positive cases, biopsies were performed after starting to administer antibiotics.
DISCUSSION: With this method, it is possible to identify the methicillin‐resistance and gram‐positive or negative species, which contributes to the appropriate antibiotics selection. Especially for cases with low‐grade infection, that is usually difficult to diagnose by conventional culture, high sensitivity is required. We demonstrated extremely high sensitivity of this method in clinical samples. On the other hand, major limitation of this method is that the inactivated bacteria are also detectable, although this property may be one advantage in clinical setting after antibiotic treatment.