BACTERIOLOGICAL FINDINGS IN PERITONSILLAR ABSCESSES IN YOUNG-ADULTS

Aspirated pus samples from 124 patients with peritonsillar abscess wer e Cultured quantitatively for aerobes and anaerobes. A total of 98% of the samples yielded bacteria. Of the 550 isolates obtained (mean, 4.4 per patient), 143 were aerobes (representing 16 species or groups) an d 407 were anaerobes (representing 40 species or groups). Aerobes were isolated from 86% of patients-alone in 20 cases and together with ana erobes in 87. The most common aerobic isolates were Streptococcus pyog enes (isolated from 45% of patients), Streptococcus milleri group orga nisms (27%), Haemophilus influenzae (11%), and viridans streptococci ( 11%). Anaerobes were isolated from 82% of the samples and as a sole fi nding from 15 abscesses. Fusobacterium necrophorum and Prevotella mela ninogenica were both isolated from 38% of patients, Prevotella interme dia from 32%, Peptostreptococcus micros from 27%, Fusobacterium nuclea tum from 26%, and Actinomyces odontolyticus from 23%. The rate of prev ious tonsillar/peritonsillar infections was lowest (25%) among patient s infected with S. pyogenes and highest (52%) among those infected wit h F. necrophorum (P < .01). Recurrences and/or related tonsillectomies were more common among patients infected with F. necrophorum than amo ng those infected with S. pyogenes (57% vs. 19%; P < .0001) or with S. milleri group organisms (43% vs. 19%; P < .05). Beta-Lactamase was pr oduced by only 38% of the 73 isolates of Prevotella species tested; ho wever, 56% of the 36 patients studied harbored one or more such strain s.