Direct microscopy of effusions obtained from peritonsillar abscesses as a complement to bacterial culturing

Effusion material was aspirated from 51 consecutive peritonsillar abscesses (34 male, 17 female; age range eight to 46 years) and subjected to direct microscopy after staining with acridine orange. Bacteria were counted per ml effusion material and their morphology was analyzed. In addition, aerobic and anaerobic bacterial culturing was performed. Effusions containing β-haemolytic streptococci Group A, which appeared as a single species, contained fewer bacteria (8 × 106 per ml, median value) than effusions harbouring a mixed flora (7 × 108 bacteria per ml, median value). Direct microscopy of effusions obtained from peritonsillar abscesses makes possible rapid identification of a single or mixed flora, which is of importance for the antibiotic treatment of the disease.