Recovery of beta-lactamase producing bacteria in pediatric infections.

The presence of beta-lactamase producing bacteria (beta LPB) was investigated in specimens obtained from 1469 children who presented with infections of the skin and soft tissue (648), upper respiratory tract (514), pulmonary sites (137), surgical sites (113), and other (57). Of 4989 bacterial isolates recovered, 910 (18%) were beta LPB, 492 (54%) aerobes, and 418 (46%) anaerobes. The beta LPB were recovered in 751 (51%) of the children. The most frequently recovered beta LPB was Staphylococcus aureus, which was recovered in 356 (47%) patients. Most isolates were recovered from patients with skin and soft-tissue infections (68% of patients), upper respiratory tract infections (49%), and pulmonary infections (35%). Bacteroides fragilis group was isolated in 35% of patients with beta LPB, mostly from surgical infections (98% of patients), pulmonary infections (36%), skin and soft-tissue infections (25%), and upper respiratory tract infections (20%). Twenty-five percent of the Bacteroides melaninogenicus group produced beta-lactamase. These organisms were recovered in 15% of patients with beta LPB. They were recovered in upper respiratory tract infections (38% of patients), pulmonary infections (22%), and skin and soft-tissue infections (7%). Other beta LPB were Pseudomonas aeruginosa (8% of total patients with beta LPB), Escherichia coli (4%), Bacteroides oralis (3%), Klebsiella pneumoniae (3%), Haemophilus influenzae (2%), Proteus (1%), and Branhamella catarrhalis (1%). The role of beta LPB in the failure of penicillin to eradicate many of the infections is discussed.