A retrospective review of cases of anaerobic empyema and update of bacteriology.

We conducted a retrospective study to update the bacteriology of 46 cases of anaerobic empyema that were originally studied between 1976 and 1993 at the Wadsworth Anaerobic Bacteriology Clinical Research Laboratory (Los Angeles). Anaerobic bacteriologic studies were completed for all 46 pleural fluid specimens, and aerobic bacteriologic studies were completed for 41 of these specimens. Thirty-seven clinical charts were available for review. A total of 161 anaerobic isolates (3.5 per patient) representing 64 species or groups were recovered. The most common isolates were as follows: Fusobacterium nucleatum (19); Prevotella oris-buccae group (13, 9 of which were P. oris); Bacteroides fragilis group (11, 4 of which were B. fragilis); pigmented Prevotella species (17, 8 of which were in the Prevotella intermedia-nigrescens group); Peptostreptococcus species (17, 9 of which were Peptostreptococcus micros); Eubacterium species (7); Lactobacillus species (8); Actinomyces species (7); and Clostridium species (7). Nineteen if the cases were of purely anaerobic etiology; of these, eight were caused by a single organism: F. nucleatum (five cases); B. fragilis (two cases); and Prevotella mangus (one case). Of the 45 aerobic isolates (1.1 per patient), viridans streptococci were most common (21 isolates), followed by group D nonenterococcal streptococcus (four isolates). Only nine gram-negative rods (six enteric and three nonenteric organisms) and one Staphylococcus aureus isolate were recovered. The susceptibility to penicillin of 64 isolates was examined with the use of the spiral gradient method; 21 (33%) of these isolates were beta-lactamase positive (MICs ranged from 1.1 to > or = 54 micrograms/mL vs < or = 0.27 micrograms/mL for beta-lactamase-negative strains).

Bacteriology of anaerobic pleuropulmonary infections: preliminary report.

A retrospective bacteriologic study of anaerobic pleuropulmonary infections diagnosed at the Wadsworth Veterans Affairs Medical Center between 1976 and 1991 was performed. There were 116 specimens from 110 patients. Available strains were reexamined using the latest tests and taxonomic schemes. Pleural fluid was believed to provide the most reliable specimen; cultures yielded an average of 3.0 anaerobes and 0.6 nonanaerobes per specimen. The most commonly encountered anaerobes were pigmented Prevotella species, nonpigmented Prevotella species, Fusobacterium nucleatum, Peptostreptococcus species, and Bacteroides species. Thirty percent of the anaerobic gram-negative rods were beta-lactamase producers.

Peritonsillar abscess, retropharyngeal abscess, mediastinitis, and nonclostridial anaerobic myonecrosis: a case report.

Peritonsillar abscess is a potentially life-threatening complication of acute tonsillitis. On occasion, peritonsillar abscess can extend to neck spaces and/or to the mediastinum. We describe a case of a patient with a peritonsillar abscess that extended to the neck, producing bilateral retropharyngeal abscesses and myonecrosis of the strap muscles. Culture of a specimen of the necrotic muscle yielded Prevotella intermedia, Prevotella buccae, Lactobacillus catenaforme, another Lactobacillus species, Peptostreptococcus anaerobius, and some nonanaerobes. Culture of the peritonsillar abscess yielded P. intermedia and P. buccae plus P. anaerobius, Peptostreptococcus asaccharolyticus, Bifidobacterium dentium, viridans and group F streptococci, and Citrobacter diversus. Culture of the retropharyngeal abscess yielded Fusobacterium nucleatum and Actinomyces odontolyticus in addition to most of the aforementioned organisms. The patient underwent repeated drainage and debridement procedures and was treated with various antimicrobial agents and ultimately recovered. This case highlights the polymicrobial nature of peritonsillar abscess and the serious complications that this infection may lead to.