Investigators from Seoul National University Children’s Hospital, Seoul, South Korea, and Jeju National University Hospital, Jeju, South Korea, conducted a prospective study comparing a methodology using blood culture bottles (BCB system) to collect samples in children with osteoarticular infections to traditional methods of collecting samples (swabs and tissue samples). Study participants were patients <18 years old with osteomyelitis and/or septic arthritis who underwent a surgical procedure at a single center between 2016 and 2019. At the time of surgery, 4 needles of 15-to-30–mm length were dipped into the wound, then inserted into the top of 4 pediatric blood culture bottles (2 aerobic and 2 anaerobic). Following this, 2 swab samples of the wound and tissue samples were collected. All specimens were transported to the microbial laboratory for processing. Information collected on study participants included demographics, diagnosis, previous antibiotic usage, and microbiology results.
The primary study outcome was rate of positive bacterial culture in the BCB system, swab, and tissue collection. Contaminants were defined and not counted as a positive result unless they were grown in ≥2 samples in an immunocompromised patient or in a child with an implant. Rates of positive cultures with the BCB system were compared individually to that of the swab or tissue sample method using McNemar tests. A secondary outcome was time to a positive result; Wilcoxon signed-rank tests were used to compare this outcome between the 3 groups.
A total of 40 patients with a mean age of 7.2 ±5.3 years were enrolled in the study. There were 17 (43%) patients with septic arthritis, 13 (33%) with osteomyelitis, and 10 (25%) with both; 20 patients (50%) were treated with antibiotics within 21 days of surgery. The rate of positive cultures was significantly higher with the BCB system (68%) than with swab collection (45%; P = 0.004) or tissue sample (38%; P <0.001). In 9 patients (23%), pathogens only were identified with the BCB system. Conversely, there were no patients for whom swab or tissue sample cultures were positive and BCB system cultures negative. Among the 20 patients who had recent antibiotic exposure, BCB system cultures were positive in 13 (65%), compared to 6 (30%) tissue sample cultures (P = 0.016) and 8 (40%) swab cultures (P = 0.063). Mean time to a positive culture was 3.5 ±0.9 days for the BCB system, which was significantly shorter than for swab cultures (4.3 ±1.1 days; P <0.001) or tissue sample cultures (4.4 ±1.1 days; P <0.001).
The authors conclude that for identification of pathogens in pediatric osteoarticular infections, the BCB system was superior to traditional culture techniques.
Dr Hennrikus has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of...