Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2017

Use of molecular methods to identify changes in Neisseria gonorrhoeae epidemiology: New South Wales, 2012-2014 (#37)

Cameron Buckley 1 , Brian Forde 2 3 , Ella Trembizki 1 , Ratan Kundu 4 , Monica Lahra 4 , Scott Beatson 2 3 , David Whiley 1 5
  1. The University of Queensland, UQ Centre for Clinical Research, Herston, QLD
  2. School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD
  3. Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD
  4. WHO Collaborating Centre for STD, Microbiology Department, South Eastern Area Laboratory Services, Prince of Wales Hospital, Sydney, NSW
  5. Pathology Queensland, Microbiology Department, Herston, QLD

Introduction:

Molecular methods can enhance our understanding of Neisseria gonorrhoeae (NG) epidemiology. Here, we used iPLEX genotyping combined with whole genome sequencing (WGS) to examine diversity and temporal differences in NG in New South Wales (NSW).

Methods:

Clinical isolates of NG acquired from NSW during the first six months of 2012 (n = 762) and 2014 (n = 863) were genotyped using Sequenom MassARRAY iPLEX technology [1], based on informative single nucleotide polymorphisms (SNPs). WGS data from 94 isolates of the most prevalent NSW genotype were subject to phylogenetic analyses (using ParSNP [2], Gubbins [3] and RAxML [4]), including comparisons with NG WGS data from 1,870 United Kingdom (UK) isolates [5].

Results:

A total of 162 distinct genotypes were identified; 36 genotypes were present in both years, 54 were observed in 2012 only and 72 in 2014 only. The 10 most common genotypes accounted for 69% of all isolates, with the majority among men who have sex with men. However, the most prevalent genotype in 2012 (22%) and second highest in 2014 (13%), was associated with heterosexuals. WGS analysis of this genotype revealed four phylogenetic subgroups, delineated by < 500 SNPs, with high similarity to several NG genomes from the UK.

Conclusion:

Overall, considerable NG genotype diversity was identified. A small number of NG genotypes accounted for a large proportion of infections. Temporal changes were observed, and indicate increasing infection rates among sexual networks, particularly heterosexuals. WGS revealed sustained transmission over the two year period and highlights likely transmission between Australia and the UK.

 

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