Microbial Flora and Antibiotic Resistance in Odontogenic Oral Abscesses in Upstate New York

Objectives: (1) Identify the most common bacteria in odontogenic oral abscesses over the past decade. (2) Identify the prevalence of antibiotic resistance of pathogens responsible for odontogenic oral abscesses to guide initial antibiotic treatment. Methods: This is a retrospective chart review conducted at a single tertiary academic medical center of adult and pediatric patients who underwent drainage of oral abscesses caused by odontogenic sources (n = 129), during which cultures of the abscess were obtained. The cultures were analyzed for type of pathogen and antibiotic sensitivities. Medical comorbidities and drainage techniques were reviewed. Results: Multiple bacteria species were identified in 59.69% of odontogenic abscesses and single bacteria species in 34.11%. The most common bacteria were alpha hemolytic streptococci (34.11%), streptococcus milleri (32.56%), prevotella strains (19.38%), and coagulase negative staphylococcus (14.73%). Clindamycin resistance was identified in stomatococcus (50%), lactobacillus (33.33%), streptococcus milleri (33.33%), staphylococcus (10%), corynebacterium (8.33%), and alpha hemolytic streptococcus (2.27%). Penicillin resistance was identified in stomatococcus (50%) and lactobacillus (33.33%). Methicillin resistance was identified in staphylococcus (10%). Erythromycin resistance was identified in streptococcus milleri (35.71%), staphylococcus (10%), corynebacterium (8.33%), and alpha hemolytic streptococcus (2.27%). Strepto-coccus milleri was also resistant to tetracycline (2.38%), and morganella morganii was resistant to ampicillin (100%) and cefazolin (100%). Conclusions: Most oral odontogenic abscesses were polymicrobial, with the most common pathogens being alpha hemolytic streptococcus, streptococcus milleri, prevotella, and coagulase negative staphylococcus. The most common antibiotic resistances were to clindamycin and erythromycin, which should be considered when deciding initial antibiotic therapy.