posted on 2019-06-25, 03:59authored byChristina Straub, Xochitl C. Morgan, Paul P. Gardner, Patrick J. Biggs, Xiaoyun Ren, Joep de Ligt, Jenny L. Draper
<p>Gonorrhoea, caused by <i>Neisseria gonorrhoeae </i>(<i>Ng</i>)<i>,
i</i>s the second most common sexually transmitted disease worldwide. Natural
competence combined with a high rate of recombination gives <i>Ng</i> an increased capability to evolve
antimicrobial resistance (AMR). <i>Ng </i>has
evolved resistance to every class of antibiotic used to treat it in the past.
Currently the recommended dual first-line treatment regime is azithromycin
coupled with ceftriaxone. However, isolated cases of superbugs, which are resistant
to both antibiotics have been reported recently, highlighting the threat of the
spread of superbugs.</p>
<p>Tracking of AMR is essential to
provide an effective treatment regime and to counteract the spread of
antimicrobial resistant pathogens. Sufficient
surveillance is lacking in many countries, including New Zealand. Since the
move to nucleic acid amplification diagnostic tests (NAAT) for detecting
gonorrhoea in New Zealand, information on AMR is limited to a national survey
every few years. </p>
<p>We
develop a cost-effective custom amplicon panel for metagenomics
sequencing to directly type <i>Ng</i> from
clinical samples and track AMR. We first tested the species specificity of
currently used typing schemes (NG-MAST and NG-STAR), since clinical samples
contain diverse microbial profiles. Our findings suggest that currently used
typing genes are <i>Neisseria</i> specific, with one exception (23S gene). The
creation of synthetic metagenomes allows the simulation of a range of clinical
samples with varying pathogen load, representative of the swabbing quality and
infection status of clinical samples. Amplicon sets will be tested in synthetic
metagenomes, prior to clinical samples. </p>
<p>Usage of the amplicon panel for
routine diagnosis of gonorrhoea will improve our ability to understand the
evolution, emergence and spread of AMR in <i>Ng</i>. Ongoing surveillance
provides key information to make informed decisions for effective treatment of
common pathogens.</p>