Microbial Flora and Antibiotic Resistance in Peritonsillar Abscesses in Upstate New York.

OBJECTIVES To identify the common bacteria in recent peritonsillar abscesses and the prevalence of antibiotic resistance and compare both between adults and children. METHODS This is a retrospective chart review at a single academic institution of patients who underwent either incision and drainage or tonsillectomy for a peritonsillar abscess between 2002 and 2012 (n=69). Medical records were reviewed for cultures, comorbidities, and drainage procedures. RESULTS Cultures obtained from 62.32% of peritonsillar abscesses were polymicrobial, and 34.78% were monomicrobial. The most common pathogens were β-hemolytic Streptococcus (31.88%), α-hemolytic Streptococcus (21.74%), Neisseria (14.49%), and Streptococcus milleri (13.04%). Group A β-hemolytic streptococcus was more common in children and Streptococcus milleri was more common in adults. Alpha-hemolytic streptococcus was resistant to clindamycin (6.67%) and erythromycin (6.67%). Streptococcus milleri was resistant to clindamycin (11.11%) and erythromycin (11.11%). Staphylococcus was resistant to penicillin (37.5%), oxacillin (25%), erythromycin (25%), and clindamycin (12.5%). CONCLUSIONS β- and α-hemolytic Streptococci, Neisseria, and Streptococcus milleri are the most common pathogens. Streptococcus milleri is more common in adults, and β-hemolytic streptococcus is more common in children. Resistance to clindamycin and erythromycin is common in Streptococci and Staphylococci, and penicillin resistance is common in Staphylococci.