Microbiology of necrotizing fasciitis associated with omphalitis in the newborn infant.

OBJECTIVE: The purpose of this study was to report the aerobic and anaerobic microbiology of periumbilical necrotizing fasciitis in newborn infants.

STUDY DESIGN: Retrospective review was done of the author's 20-year experience.

RESULTS: Specimens obtained from 11 newborn infants with periumbilical necrotizing fasciitis were cultured for aerobic and anaerobic bacteria. A total of 38 bacterial isolates was recovered: 21 aerobic and facultative and 17 anaerobic. Aerobic or facultative bacteria only were present in 1 specimen (9%), anaerobes only in 2 (18%), and mixed aerobic and anaerobic flora in 8 (73%). Multiple organisms were recovered from all instances and the number of isolates varied from two to six (average 3.5 isolates per specimen). The predominant isolates were Peptostreptococcus sp. (7 isolates); Bacteroides fragilis group (6); streptococcus group B (4); and Staphylococcus aureus, streptococcus group D, Escherichia coli, and Proteus mirabilis (3 each). All patients underwent extensive debridement and resection, and they received supportive and antimicrobial therapy. Six (55%) of the patients died.

CONCLUSIONS: These findings illustrate the polymicrobial aerobic-anaerobic flora of periumbilical necrotizing fasciitis.