Rapid sensitive molecular diagnosis of pyogenic spinal infections using methicillin-resistant Staphylococcus-specific polymerase chain reaction and 16S ribosomal RNA gene-based universal polymerase chain reaction.
BACKGROUND
Rapid diagnosis and accurate detection of etiological agents in pyogenic spinal infection (PSI) patients are important.


OBJECTIVE
The purpose of this study was to evaluate the clinical usefulness of methicillin-resistant Staphylococcus-specific polymerase chain reaction (MRS-PCR) and broad-range universal PCR (U-PCR) for diagnosing PSI.


METHODS
A prospective diagnostic study.


METHODS
Thirty-two clinically suspect PSI patients and six control patients who underwent computerized tomography-guided biopsy and/or surgical treatment were enrolled.


METHODS
Tissue samples were examined by microbiological culture, histopathology, and real-time PCR (MRS-PCR and U-PCR). The diagnostic accuracy of real-time PCR was analyzed based on the definitive diagnosis of infection, defined as a positive result from microbiological culture or histopathology.


RESULTS
All six control subjects were negative for PSI for all analyses. Twelve clinically suspect PSI subjects received definitive diagnoses (PSI group). The non-PSI group consisted of six control subjects plus the remaining 20 patients from the PSI clinically suspect group. MRS-PCR results were positive for all MRS-cultured PSI subjects. U-PCR was positive for all subjects in the PSI group with one discrepancy between real-time PCR and microbiological culture results in differentiation between gram-positive and gram-negative bacteria. In the non-PSI group, MRS-PCR and U-PCR were positive in three and seven cases, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of MRS-PCR for diagnosing MRS infection were 1.00, 0.91, 0.57, and 1.00, respectively; those for the diagnosis of bacterial infection with U-PCR were 1.00, 0.73, 0.63, and 1.00, respectively.


CONCLUSIONS
Identification of MRS infection and ability to differentiate between gram-positive and gram-negative bacteria is rapidly achieved using MRS-PCR and U-PCR. Real-time PCR provides a sensitive molecular diagnosis of PSI and may contribute to antibiotic selection.
Yokohama City University School of Medicine, Department of Orthopaedic Surgery, 3-9 Fukuura, Kanazawa-ku, Yokohama, Japan. Electronic address: hyonmin@hotmail.com.
Hyonmin
H
Choe
Yokohama City University School of Medicine, Department of Orthopaedic Surgery, 3-9 Fukuura, Kanazawa-ku, Yokohama, Japan.
Yoichi
Y
Aota
Yokohama City University School of Medicine, Department of Orthopaedic Surgery, 3-9 Fukuura, Kanazawa-ku, Yokohama, Japan.
Naomi
N
Kobayashi
Yokohama City University School of Medicine, Department of Orthopaedic Surgery, 3-9 Fukuura, Kanazawa-ku, Yokohama, Japan.
Yushi
Y
Nakamura
Yokohama City University School of Medicine, Department of Orthopaedic Surgery, 3-9 Fukuura, Kanazawa-ku, Yokohama, Japan.
Yusuke
Y
Wakayama
Yokohama City University School of Medicine, Department of Orthopaedic Surgery, 3-9 Fukuura, Kanazawa-ku, Yokohama, Japan.
Yutaka
Y
Inaba
Yokohama City University School of Medicine, Department of Orthopaedic Surgery, 3-9 Fukuura, Kanazawa-ku, Yokohama, Japan.
Tomoyuki
T
Saito
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D020459:Genes, rRNA / Q000235:genetics*; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000472:pathogenicity*; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D013122:Spinal Diseases / Q000175:diagnosis* / Q000235:genetics / Q000382:microbiology; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000235:genetics
D012336:RNA, Ribosomal, 16S
MRS-PCR; Melting peak analysis; Pyogenic spinal infection; Real-time PCR; Universal PCR