Background There is a growing concern due to the emergence of multi-drug resistance developed in Neisseria gonorrhoeae. A rapid molecular test could provide antimicrobial susceptibility knowledge prior to start of treatment and decrease the turnaround time from current culture methods (7 days). The aim was to evaluate the clinical performance of the ResistancePlus GC assay (SpeeDx) compared to the in-house PCR and antimicrobial susceptibility results for ciprofloxacin.

Methods Antimicrobial susceptibility data was captured on all GC culture positives from 2015–2017 in Scotland. A gyrA real-time PCR was used to detect for ciprofloxacin resistance in N. gonorrhoeae. In this study 168 samples were selected from a range of sites (Cervical/vaginal, Rectal, Urine or Throat). Results were compared to susceptibility results of cultures isolated from the same patient episode (within 14 days). The culture isolates displayed a range of MICs with 84 susceptible and 84 resistant to ciprofloxacin.

Results Ciprofloxacin resistance was seen in 420/1338 episodes (31.4%) in 2017. The ResistancePlus GC assay was able to detect N. gonorrhoeae in all of the samples (100%) and gyrA in 164/168 samples (97.6%).The 4 samples with gyrA undetected had high Ct’s (≥35) in a 2^nd line real-time PCR for porA. In total 162/164 gyrA results matched the phenotype of a culture isolate taken from the same episode (98.7%). Further analysis showed that performing the assay on the discrepant culture isolates matched the phenotype result.

Conclusion The ResistancePlus GC assay performed well on clinical samples and could offer ciprofloxacin susceptibility testing within 4 hours to a laboratory service. This would therefore allow for an alternative antibiotic to be prescribed. Modeling based on current episodes in Scotland could mean that ciprofloxacin would be able to be used in ≥50% of episodes which provides an exciting new approach to GC treatment.

Disclosure No significant relationships.