Culture-independent analysis of the bacteriology associated with acute otitis media in Indigenous Australian children

    Student thesis: Doctor of Philosophy (PhD) - CDU

    Abstract

    Otitis media is endemic in many remote Indigenous Australian communities. Children in remote communities develop otitis media in the first weeks of life and are at high-risk of progression to chronic suppurative otitis media (CSOM). Current therapeutic and preventive interventions are of limited benefit. This thesis presents a culture-independent analysis of the bacteriology associated with acute otitis media in Indigenous children from the Northern Territory. The objective of the study was to use culture-independent methods to better understand the bacteriology underlying acute otitis media in this population. Principle findings from the study are as follows: 1. Nasopharyngeal total or pathogenic bacterial loads are unsuitable as prognostic indicators of clinical antibiotic treatment outcomes in Indigenous children with acute otitis media. 2. Alloiococcus otitidis is present in ear discharge from Indigenous children with acute otitis media, potentially as a secondary middle ear pathogen. Further studies to test for A. otitidis in CSOM are warranted. 3. T-RFLP can provide broad characterisation of bacterial communities in upper respiratory specimens; however, it is limited by methodological biases which result in underestimation of bacterial richness. 4. Despite the methodological limitations, T-RFLP analysis demonstrated significant differences between nasopharyngeal and ear discharge bacterial communities in Indigenous children with acute otitis media with perforation, suggesting divergence of the middle ear microbiome following secondary infection by canal flora. 5. 16S rRNA gene microarray (PhyloChipTM) analysis of ear discharge from Indigenous children with acute otitis media with perforation indicates a high-level of bacterial richness which is hypothesised to contribute to progression to CSOM. Prospective longitudinal studies are now required to better understand the canal flora before perforation, the microbiology of acute otitis media immediately following perforation, and microbiomic changes associated with prolonged perforation. Such studies will aid understanding of the pathogenesis of acute otitis media with perforation and progression to CSOM, and potentially reveal new therapeutic targets or prevention strategies.
    Date of Award2011
    LanguageEnglish
    Awarding Institution

    Cite this

    Culture-independent analysis of the bacteriology associated with acute otitis media in Indigenous Australian children
    Marsh, R. (Author). 2011

    Student thesis: Doctor of Philosophy (PhD) - CDU