title: Direct detection of markers associated with Neisseria gonorrhoeae antimicrobial resistance in New Zealand using residual DNA from the Cobas 4800 CT/NG NAAT assay.
abstract: OBJECTIVE
  To use nucleic acid amplification techniques (NAAT) for detection of markers associated with gonococcal antimicrobial resistance (AMR) in non-cultured clinical samples to enhance surveillance of Neisseria gonorrhoeae AMR in New Zealand.
  
  
  METHODS
  A total of 198 clinical samples from patients living in two cities, Wellington and Auckland and the more rural region of Gisborne, New Zealand, which were positive for N. gonorrhoeae by the Cobas 4800 were tested for three markers that predict reduced susceptibility or resistance to three antibiotics. Residual DNA extracts from the Cobas 4800 NG/CT test were tested for a single-nucleotide polymorphism in the gyrA gene at codon 91 associated with quinolone resistance; a sequence on the plasmid in penicillinase-producing N. gonorrhoeae (PPNG) which confers resistance to penicillin and the mosaic penA sequence associated with reduced susceptibility to extended-spectrum cephalosporins in N. gonorrhoeae.
  
  
  RESULTS
  A total of 186/198 (94%) of the samples provided a valid result on gyrA genotyping, confirming the utility of N. gonorrhoeae DNA extracted by the Roche Cobas 4800 CT/NG test for subsequent detection of AMR markers. The NAAT results for Wellington, Auckland and Gisborne, respectively, showed that 77%, 33% and 32% of samples had the marker associated with quinolone resistance, while 4%, 15% and 0% were positive for the PPNG plasmid marker, and 9%, 5% and 0% samples were positive for mosaic penA sequence.
  
  
  CONCLUSIONS
  The use of residual clinical DNA samples from the Cobas 4800 CT/NG test proved an efficient and effective method for performing AMR genotyping. These data also show for the first time the presence of gonococci with a mosaic penA sequence in New Zealand. Overall, the results further highlight the potential of molecular methods to aid N. gonorrhoeae AMR surveillance, particularly for regions where gonococcal culture is no longer performed.
authors.affiliation: Aotea Pathology Ltd, Wellington, New Zealand.
authors.forename: Mackenzie
authors.initials: M
authors.lastname: Nicol
authors.affiliation: Queensland Paediatric Infectious Diseases Laboratory, QCMRI, The University of Queensland, The Royal Children's Hospital, Brisbane, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Whiley
authors.affiliation: Massey University, Institute of Food, Nutrition & Human Health, College of Health, New Zealand.
authors.forename: Mary
authors.initials: M
authors.lastname: Nulsen
authors.affiliation: Aotea Pathology Ltd, Wellington, New Zealand.
authors.forename: Collette
authors.initials: C
authors.lastname: Bromhead
mesh_terms: D024881:Drug Resistance, Bacterial; D005260:Female; D005798:Genes, Bacterial; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods*; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009344:Neisseria gonorrhoeae / Q000187:drug effects* / Q000235:genetics*; D009520:New Zealand; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*
chemical_list: D005819:Genetic Markers
keywords: ANTIBIOTIC RESISTANCE; GONORRHOEA; NEISSERIA GONORRHOEA; SURVEILLANCE