Clinical and Microbiological Characterization of Osteoarticular Infections in Children from a Clinic in Rionegro, Antioquia

Introduction: Osteomyelitis and septic arthritis are common invasive bacterial infections in children. Objective: To describe the microorganisms, antimicrobial susceptibility, and microbiological diagnostic procedures. Methods: A case series of children with a confirmed diagnosis, from 2017 to 2022, was characterized. Results: Forty-eight out of 84 patients were included in the study. The diagnoses were osteomyelitis in 20.8%, septic arthritis in 37.5% and osteoarthritis in 41.6% of cases. Isolated microorganisms included methicillin-susceptible Staphylococcus aureus (MSSA) in 30.7% of cases, methicillin-resistant S. aureus (MRSA) in 28.8%, Pseudomonas aeruginosa in 5.7%, S. epidermidis in 3.8%, Escherichia coli in 3.8%, Enterococcus faecalis in 3.8%, Aeromonas hydrophila in 3.8%, Mycobacterium tuberculosis in 1.9%, and Salmonella spp. in 1.9%, among others. In 40 infections originating from skin and soft tissues, orthopedic hardware, limb trauma, and without an identified source, MSSA/MRSA predominated (75%). MSSA/MRSA showed susceptibility to vancomycin at 100%, trimethoprim-sulfamethoxazole at 100% and 93%, and clindamycin at 100% and 86.6%, respectively. Blood cultures (n=22), synovial tissue cultures (n=7), bone cultures (n=28), and bone pus or synovial fluid in blood culture bottles (n=3) were 100% positive. Conclusions: S. aureus was the most frequent microorganism with a high proportion of MRSA. MRSA exhibited high susceptibility to trimethoprimsulfamethoxazole and vancomycin. The high positivity of primary cultures suggests the importance of always obtaining them.