Slackia Exigua Oral Screening and Prevalence Among Orthodontic Patients

Objectives: Slackia exigua is a Gram-positive anaerobic bacillus whose presence, as recent evidence suggests, may be indicative of oral disease, namely periodontitis. It is frequently isolated in periodontal lesions and research shows that serum antibody titers were elevated in patients with periodontitis. Based upon this evidence, the goal of this project is to screen the oral cavity for S. exigua in orthodontic patients with brackets.
Methods: Using an IRB-approved protocol, paper points were used to swab the buccal surface of the upper first molar, the lingual surface of the lower central incisor, the gingival crevice of the upper central incisor, and the dorsum of the tongue. Unstimulated saliva was collected as well. Bacterial DNA isolation has been performed for each sample and detection of relative concentrations was performed using NanoDrop prior to qPCR screening in order to detect the presence of S. exigua.
Results: Currently twenty one (n=21) patients have consented to participate with more than one hundred distinct oral sites sampled to date. Demographic analysis has revealed approximately three-fourths (71.5%) of patients were non-White or minority, with a smaller percentage self-identified as White (28.5%). The majority of patients were pediatric under the age of 18 (57.2%). DNA isolation was successful with the range of DNA concentrations between 1.01-1.62 ug. The average DNA purity (A260:A280) for each site was: gingival crevice 1.70, upper molar 1.69, lingual incisor 1.67, dorsal tongue, 1.63, saliva 1.62. Differential screening results for these sites has been observed and analysis is on-going.
Conclusions: Few studies of Slackia exigua have been performed to date. However, the results of this project may provide preliminary data that S. exigua may be an important oral organism as a screening tool for oral diseases with specific locations to determine where it may function in the oral cavity.