Microbiology of retroperitoneal abscesses in children

Samples of pus from 41 children with retroperitoneal abscess treated between 1974 and 1994 yielded a total of 125 organisms (3.0 isolates/specimen); 58 isolates were aerobic and facultative species (1.4/specimen) and 67 were anaerobic (1.6/specimen). Aerobic bacteria only were isolated from 7 (17%) abscesses, anaerobic bacteria only from 3 (7%) and mixed aerobic and anaerobic bacteria from 31 (76%); 34 (83%) infections were polymicrobial. The predominant aerobic and facultative isolates were Escherichia coli (19 isolates) and Staphylococcus aureus (6), and the predominant anaerobes were Peptostreptococcus spp. (18 isolates), Bacteroides spp. (22) and Prevotella spp. (5).