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.