Performance of TEM-PCR vs. Culture for Bacterial Identification in Pediatric Musculoskeletal Infections

BACKGROUND: Musculoskeletal infections (MSI) in children require prompt diagnosis and treatment due to risk of local tissue damage and metastatic bacterial spread. Staphylococcus aureus is the leading cause of MSI and readily grows in culture; however, receipt of antibiotics prior to culture and the frequency of fastidious organisms in young children (e.g., Kingella kingae) often leads to negative cultures and broad treatment regimens. Thus, there is a need for improved rapid diagnostics in children with MSI. In this study, we compared the detection of MSI pathogens by culture and by target-enriched multiplex PCR (TEM-PCR™) in children with MSI. METHODS: Synovial fluid and bone samples were collected from patients with MSI (n = 25, 0.5–18 years). Bacterial cultures and antibiotic susceptibility testing (AST) was performed by the Vanderbilt University Medical Center clinical laboratory. Additionally, samples were evaluated by TEM-PCR for detection of S. aureus [including methicillin and clindamycin resistance genes and the Panton–Valentine leukocidin (PVL) locus], K. kingae, Haemophilus influenzae, Streptococcus pyogenes, and Streptococcus pneumoniae. RESULTS: TEM-PCR detected a pathogen in 20/25 subjects (80%), compared with 17/25 (68%) by culture. S. aureus was identified in 18 subjects, one of which was identified by TEM-PCR and not by culture. TEM-PCR also identified 2 subjects with K. kingae infection; neither was identified by culture. TEM-PCR detection of methicillin resistance and clindamycin resistance was 100% concordant with AST in the clinical laboratory. Genes encoding PVL were identified in 8/18 (44%) S. aureus samples. No bacterial co-detections were identified, and no other pathogens were identified by TEM-PCR or culture. Finally, there were no subjects with positive bacterial cultures and negative TEM-PCR results. CONCLUSION: Rapid diagnostic assays, such as TEM-PCR, may be useful adjuncts to conventional, culture-based testing for children with MSI. Advantages include rapid identification of pathogen and early detection of antibiotic resistance genes. In a single multiplex assay, TEM-PCR provided reliable identification of MSI pathogens, with the potential for informing antibiotic selection early in the disease course. DISCLOSURES: J. Wood Jr., Diatherix: Investigator, Research support; C. Sesler, Diatherix Laboratories, LLC: Employee, Salary; D. Stalons, Diatherix Laboratories: Employee, Salary; E. Grigorenko, Diatherix Laboratories: Employee, Salary; C. B. Creech, Diatherix: Grant Investigator, Grant recipient; I. Thomsen, Diatherix: Investigator, Research support