Culture of Micro-organisms Associated with Odontogenic Infections

Objectives: To determine the composition of micro-organisms associated with odontogenic infection
To determine the association between the various micro-organisms and the fascial spaces
To determine the antibiotic resistance of the micro-organisms cultured
Methods: The study population consisted of fifty-five patients treated for odontogenic infection at the Department of Maxillo-Facial and Oral Surgery, University of the Western Cape (UWC), South Africa between September and November 2018. Puss swabs were done in 49.1% (n=27) of these cases. The microbiology reports were analysed for bacterial growth and antibiotic resistance. Microsoft Excel was used to capture and analyse the data.
Results: The sample included 13 females and 14 males with a mean age of 30.37 years. The most commonly isolated organisms were of the Streptococcus family (33.3%), of which Streptococcus mitis/oralis was most common (11.1%). Normal flora were isolated in 7 cases (25.9%), while 5 cases reported no bacterial growth. Mixed bacterial growth was observed in 11 cases (40.7%). Gram negative bacilli were cultured from pus swabs taken from the submandibular space in ten patients (37%), compared to superficial spaces (buccal and canine), which only exhibited gram positive organisms. Bacterial growth from samples taken from HIV-infected patients revealed gram negative bacilli. In 3 cases (11.1%), organisms were resistant to penicillin, but sensitive to clindamycin and gentamycin.
Conclusions: In accordance with previous studies, Streptococci remained the most commonly isolated organisms for odontogenic infections. Gram positive organisms were more frequently found in superficial fascial spaces where as gram negative bacilli were more common in the submandibular space. Bacterial resistance to penicillin poses a serious threat in the treatment of odontogenic infection, hence it’s vital that the use of these antibiotics be reserved for only resistant organisms.