The aim of this proposal is to design and evaluate a novel DNA probe- based assay for antibiotic susceptibility testing. The test will identify and detect resistant organisms in both pure and mixed samples. Phase I of this work will focus on three key organisms. Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Treponema denticola. The assay format will consist first of a brief culture step of the sample in a growth medium with and without antibiotic. Samples are then lysed and added to a reagent cassette. A probe analysis card having beads specific for each of the target organisms is then added to the sample and automated processing is initiated. Results for the DNA probe assay are ready in about 30 minutes and are read visually. The advantages of this technology are that limited microbiological culture is required, an objective answer can be arrived at rapidly, and the assay is broadly applicable to a variety of antibiotics. In phase I, the feasibility of the rapid testing concept will be studied using cultured sensitive and resistant organisms and the antibiotic tetracycline. In phase II, we will expand the panel of organisms that can be tested and evaluate this assay on patient samples.Proposed commercial application:The goal of this proposal is to design a DNA-probe based antibiotic susceptibility test for periodontal organisms. The proposed assay will require minimal microbiological handling and will allow a relatively rapid determination of susceptibility to a wide range of antibiotics. This test will aid the practitioner in determining the appropriate antibiotic therapy in a timely manner.National Institute of Dental Research (NIDR)
