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

Abstract

Objectives: (1) Identify the most common bacteria in peritonsillar abscesses over the past decade. (2) Identify the prevalence of antibiotic resistance of pathogens responsible for peritonsillar abscesses to guide initial antibiotic treatment. Methods: This is a retrospective chart review looking at adult and pediatric patients who presented to a single tertiary academic center in upstate New York from 2002 through 2012 and underwent either incision and drainage or quincy tonsillectomy for a peritonsillar abscess (n = 69), during which cultures of the abscess were obtained. Cultures from the abscess were reviewed for bacteria and antibiotic sensitivities. Patient medical records were reviewed for age, medical comorbidities, prior episodes, immune-compromised state, type of drainage procedure done and complications, and whether more than one procedure was needed. Results: Of the peritonsillar abscesses, 62.32% were polymicrobial and 34.78% were monomicrobial. The most common pathogens were beta hemolytic streptococcus (31.88%), alpha hemolytic streptococcus (21.74%), Neisseria (14.49%), and Streptococcus milleri (13.04%). Staphylococus was resistant to oxacillin (25%), erythromycin (25%), clindamycin (12.5%), and penicillin (12.5%). 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%). Conclusions: Peritonsillar abscesses are most commonly polymicrobial, with beta and alpha hemolytic streptococci, Neisseria, and S milleri as the most prevalent pathogens. In addition, antibiotic resistance to clindamycin and erythromycin is common across streptococcal strains and staphylococcal strains, and methicillin resistance is also common in staphylococcal strains responsible for peritonsillar abscesses.