The Association of Molecular Characteristics, Vancomycin MIC and Clinical Outcomes in Methicillin-susceptible Staphylococcus aureus Osteoarticular Infections in Children

• Published in: Open forum infectious diseases 2017-10, Vol.4 (suppl_1), p.S3-S3
• Main Authors: McNeil, Jonathon, Vallejo, Jesus G, Rosas, Louie, Mason, Edward O, Kaplan, Sheldon L, Hulten, Kristina G
• Format: Article
• Language: English
• Subjects: Abstracts
• ISSN: 2328-8957; 2328-8957
• DOI: 10.1093/ofid/ofx162.005

Abstract Background Methicillin-resistant Staphylococcus aureus, particularly those belonging to the USA300 pulsotype and bearing Panton–Valentine leucocidin (pvl), have been well described to cause severe osteoarticular infection (OAI). Vancomycin minimum inhibitory concentration (MIC) ≥ 1.5 µg/ml has been demonstrated to contribute to disease severity in MRSA bacteremia. Little data exist to describe the spectrum of outcomes in MSSA OAI in terms of molecular characteristics and vancomycin MIC. Methods OAI isolates were identified from 2011 to 2016 and subjected to vancomycin E-tests. MSSA isolates underwent PFGE, PCR for pvl, and a stepwise assay to determine accessory gene regulator (agr) group. A review of the medical record was performed. Orthopedic complications included chronic osteomyelitis, pathologic fracture, and growth arrest. Results During the study period, 167 cases of S. aureus OAI were identified; 115 were MSSA (68.9%). 29.1 and 26.1% of MSSA isolates were USA300 and pvl positive, respectively. USA300 isolates were more likely to be pvl-positive (66.7 vs. 13.6%, P