Aerobic and anaerobic microbiology of necrotizing fasciitis in children.

Specimens obtained from eight children with necrotizing fasciitis (NF) were cultured for aerobic and anaerobic bacteria. A total of 21 isolates were recovered, 13 anaerobic and 8 aerobic or facultatives. The facultative organism Streptococcus pyogenes was present alone in two (25%) instances, and mixed aerobic and anaerobic bacteria were isolated in six (75%). The predominant isolates were Peptostreptococcus spp. (6 isolates, including 3 Peptostreptococcus magnus). S. pyogenes (4), Bacteroides fragilis group (3), Clostridium perfringens (2), Escherichia coli (2), and Prevotella spp. (2). Organisms similar to the ones isolated from the NF aspirates were recovered in the blood of all patients except one. These included S. pyogenes (3 isolates). B. fragilis group (2), E. coli (1), and P. magnus (1) and Clostridium perfringens (1). All patients underwent surgical fasciotomy, and four required skin grafting. Antimicrobials were administered to all children. Despite extensive resection and intense supportive therapy, three patients died from sepsis accompanied by shock acidosis and disseminated intravascular coagulation. These findings illustrate the polymicrobial aerobic-anaerobic flora of NF in children.