Microbiological features and pathogenesis of peritonsillar abscesses

Abstract

Samples of pus aspirated from 53 peritonsillar abscesses were examined in detail for aerobic and anaerobic bacteria, and the microbiological results correlated with clinical data in 44 cases. In 45 samples (85%) cultures were positive: 7 yielded organisms consistent with an aerobic infection, mainly Lancefield group A beta-haemolytic streptococci (5/7), and 38 yielded organisms consistent with an anaerobic infection. The anaerobic infections were usually mixed, but in two cases Fusobacterium necrophorum was isolated in pure culture. Peptostreptococcus micros and Streptococcus milleri were the predominant isolates in this group. Direct Gram stain smear and gas-liquid chromatography were useful indicators of the type of infection present. Samples from ten patients (18.9%) grew one or more beta-lactamase-producing isolates. Of the 25 patients prescribed antibiotics by their general practitioners prior to admission, 18 received one or more beta-lactam antibiotics. Most cases of peritonsillar abscess were due to mixed anaerobic infections, Lancefield group A beta-haemolytic streptococci playing a central role in only a minority of cases. In light of these findings and the possibility of infection with beta-lactamase-producing isolates, it is suggested that the first-line antibiotic therapy in this group of patients should include a chemotherapeutic agent directed against anaerobic bacteria.

Significant pathogens in peritonsillar abscesses

“…Interpretation of bacteriologic findings in former studies is made even more obscure by the fact that in many studies patients with and without prior antibiotic treatment are pooled together. Some studies have found quantitative and qualitative differences in bacteriologic culture results after antibiotic treatment [3,6,8,13] while others have not [4][5]. Only Flodström et al [15], in 1976, have studied the microbiologic flora exclusively in PTA patients with no prior antibiotic treatment.…”

“…Several studies have looked at the bacteriology of PTA aspirates [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. A mixture of aerobic and anaerobic bacteria is commonly isolated.…”

“…The importance of anaerobes in PTA formation has been suspected for decades [3][4][5][6][7], however, few attempts have been made to explore which strains are of pathogenic importance. Immune responses to Fusobacterium nucleatum and Prevotella intermedia have been detected in patients with PTA [23][24], as well as in patients suffering from recurrent acute tonsillitis (RT) [25], AT [26], peritonsillar cellulitis [23][24], and mononucleosis [27].…”

Extensive thoracolumbosacral vertebral osteomyelitis after Lemierre syndrome

“…This is an anaerobic, Gram-negative bacterium which can be part of the normal oropharyngeal flora. F. necrophorum can cause a variety of relatively minor infections such as otitis media or sinusitis and is a common pathogen in tonsillitis and peritonsillar abscesses [13][14][15][16]. It is not known how often localized Fusobacterium infections progress to the lifethreatening Lemierre's syndrome.…”

Microbiologia dos abscessos peritonsilares

“…Peritonsillar abscess is characterized by a purulent secretion collected between the fibrous capsule of the palatine tonsil and the pharyngeal superior constrictor muscle 1,2 . The proper treatment for this infection aims at avoiding serious complications which include its extension into deep spaces in the neck and its rupture with secretion being aspirated towards lower airways.…”