Prevotella and Porphyromonas infections in children.

From 1974 to 1994, 504 isolates of Prevotella and Porphyromonas spp. were obtained from 435 (21%) of 2033 specimens from 418 children. They included 160 (32%) Pr. melaninogenica, 105 (21%) Pr. intermedia, 84 (17%) P. asaccharolytica, 58 (12%) Pr. orisbuccae, and 58 (12%) Pr. oralis. Most Prevotella and Porphyromonas spp. were isolated from abscesses (176), pulmonary infections (85), ear infections (82), wound infections (44), peritonitis (38), paronychia (15) and chronic sinusitis (14). Predisposing conditions were noted in 111 (27%) of the cases; these included previous surgery in 41 (10%), foreign body in 36 (9%), neurological deficiencies in 29 (7%), immunodeficiency in 21 (5%), steroid therapy in 12 (4%), diabetes in 8 (2%) and malignancy in 7 (2%). Prevotella and Porphyromonas spp. were the only isolates in 14 (3%) patients, and mixed infection was encountered in 404 (97%). The micro-organisms most commonly isolated with Prevotella and Porphyromonas spp. were anaerobic cocci (393 isolates), Fusobacterium spp. (108), Bacteroides spp. (B. fragilis group) (95), Escherichia coli (56) and other gram-negative anaerobic bacilli (52). Most Bacteroides spp. and E. coli were isolated from intra-abdominal infections and skin and soft tissue infections around the rectal area, whereas most Fusobacterium spp. were isolated from oropharyngeal, pulmonary and head and neck sites. beta-Lactamase production was detected in 191 (38%) Prevotella and Porphyromonas isolates from all body sites. All patients received antimicrobial therapy, and surgical drainage was performed in 173 (41%) cases. Four patients died from their infection. These data illustrate the spectrum and importance of Prevotella and Porphyromonas spp. in infections in children.