Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2016

A brief note on the molecular characteristics of Alloiococcus. otitidis: an organism isolated from Indigenous and non-Indigenous children in the Hunter region (#304)

Joanne Barfield 1 2 3 , Chris Ashurst-Smith 1 3 , Caroline Blackwell 2 3 , John Ferguson 3 4 , Rod Givney 3 4 , Sharon Hall 3 , Kelvin Kong 3 5 , Rodney Scott 3 6
  1. Department of Microbiology, Pathology North, Newcastle
  2. School of Biomedical Science and Pharmacy, Faculty of Health, University of Newcastle, Newcastle
  3. Hunter Medical Research Institute, Newcastle, NSW
  4. Department of Microbiology Pathology North, School of Biomedical Science and Pharmacy, University of Newcastle, Newcastle, NSW
  5. School of Medicine and Public Health, Faculty of Health, University of Newcastle, Newcastle, NSW
  6. Department of Molecular Medicine Pathology North, Newcastle

Our group has a long term interest in the role of Alloiococcus otitidis in otitis media with effusion (OME) in Indigenous and non- Indigenous communities.1 Our experimental results indicate A. otitidis is capable of producing high levels of inflammatory mediators in vitro equal to or greater than those elicited by conventional otopathogens; 2,3 these findings suggest it could contribute to the pathological processes underlying ear disease.  One major observation from our previous studies was the absence of classic otopathogens; A. otitidis was the major isolate.  More recent studies demonstrated this bacterium in the outer ear canal in 26/34 (76%) of children undergoing routine ENT surgical procedures.  

To elucidate further the role of A. otitidis in the ear canal, we have used Illumina, Next Generation Sequencing (NGS) technologies to sequence the whole genomes of isolates of A. otitidis with different phenotypic characteristics obtained from both Indigenous and non-Indigenous populations in the Hunter region. The objective was to assess genomic data for elements that code for known virulence factors present in pathogenic organisms. These investigations will complement studies on antibiotic susceptibilities and ongoing in vitro studies on attachment to and invasion of human cell lines to elucidate the pathogenic potential of A. otitidis in ear infections.

  1. Ashhurst-Smith C, Hall ST, Stuart J, Burns CJ, Liet E, Walker PJ, Dorrington R, Eisenberg R, Robilliard M, Blackwell CC. Alloiococcus otitidis: an emerging pathogen in otitis media. J Infect. 2012 Feb;64(2):233-5. doi: 10.1016/j.jinf.2011.11.008.
  2. Ashhurst-Smith C, Hall ST, Burns CJ, Stuart J, Blackwell CC. In vitro inflammatory responses elicited by isolates of Alloiococcus otitidis obtained from children with otitis media with effusion. Innate Immun. 2014 Apr;20(3):320-6. doi: 10.1177/1753425913492181
  3. Ashhurst-Smith C, Hall ST, Burns CJ, Stuart J, Blackwell CC. Induction of inflammatory responses from THP-1 cells by cell-free filtrates from clinical isolates of Alloiococcus otitidis. Innate Immun. 2014 Apr;20(3):283-9. doi: 10.1177/1753425913490535.