Characterization of Bacteria Causing Acute Otitis Media Using Raman Spectroscopy

Abstract

Otitis media (OM), an inflammatory disease of the middle ear, is the most frequent cause of physician visits and prescription of antibiotics for children. Current methods to diagnose OM rely on varying symptoms and visual changes related to the tympanic membrane. Raman spectroscopy (RS) is an optical technique that non-invasively provides information about molecular structure and composition of a sample. This dissertation tested the hypothesis that RS could be used to detect and identify clinically relevant bacteria based on biochemical differences executed in three parts. First, the three main pathogens (Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae) that cause acute OM were successfully characterized using Raman microspectroscopy. Second, drug-resistant pathogens were evaluated using Raman microspectroscopy, which showed that this technique can be used to identify genetic variants of Staphylococcus aureus and discriminate between methicillin-resistant and methicillin-sensitive strains. Third, Raman microspectroscopy was utilized to differentiate pathogens in a biofilm tissue model. Furthermore, a fiber-optic RS probe was designed and tested using a portable RS system to measure the feasibility of detecting infection in vivo from patients suffering from recurrent ear infections. Findings from this dissertation highlight the potential of using RS to rapidly identify bacteria causing OM and other infectious diseases, which may aid in streamlining clinical decisions and reducing antibiotic-resistance.