Impact of molecular ciprofloxacin resistance testing in management of gonorrhoea in a large urban clinic

Emily Goldstein; Elizabeth Moss; Susan Bennett-Slater; Lynne Ferguson; Carol McInally; Martin McHugh; Alexandra Maxwell; Andrew Winter; Rory N Gunson

doi:10.1136/sextrans-2023-056099

Impact of molecular ciprofloxacin resistance testing in management of gonorrhoea in a large urban clinic

Sex Transm Infect. 2024 May 3:sextrans-2023-056099. doi: 10.1136/sextrans-2023-056099. Online ahead of print.

Authors

Emily Goldstein¹, Elizabeth Moss², Susan Bennett-Slater³, Lynne Ferguson³, Carol McInally³, Martin McHugh⁴, Alexandra Maxwell², Andrew Winter², Rory N Gunson³

Affiliations

¹ West of Scotland Specialist Virology Centre, NHS Greater Glasgow and Clyde, Glasgow, UK emily.goldstein@ggc.scot.nhs.uk.
² Sandyford Sexual Health Services, NHS Greater Glasgow and Clyde, Glasgow, UK.
³ West of Scotland Specialist Virology Centre, NHS Greater Glasgow and Clyde, Glasgow, UK.
⁴ Scottish Bacterial STI Reference Laboratory, NHS Lothian, Edinburgh, UK.

PMID: 38702191
DOI: 10.1136/sextrans-2023-056099

Abstract

Objectives: Antibiotic resistance in gonorrhoea is of significant public health concern with the emergence of resistance to last-line therapies such as ceftriaxone. Despite around half of Neisseria gonorrhoeae isolates tested in the UK being susceptible to ciprofloxacin, very little ciprofloxacin is used in clinical practice. Testing for the S91F mutation associated with ciprofloxacin resistance is now available in CE-marked assays and may reduce the requirement for ceftriaxone, but many patients are treated empirically, or as sexual contacts, which may limit any benefit. We describe the real-world impact of such testing on antimicrobial use and clinical outcomes in people found to have gonorrhoea in a large urban UK sexual health clinic.

Methods: Molecular ciprofloxacin resistance testing (ResistancePlus GC assay (SpeeDx)) was undertaken as an additional test after initial diagnosis (m2000 Realtime CT/NG assay (Abbott Molecular)) in those not already known to have had antimicrobial treatment. Data from a 6-month period (from March to September 2022) were analysed to determine treatment choice and treatment outcome.

Results: A total of 998 clinical samples tested positive for N. gonorrhoeae in 682 episodes of infection. Of the 560 (56%) samples eligible for resistance testing, 269 (48.0%) were reported as wild-type, 180 (32.1%) were predicted to be resistant, 63 (11.3%) had an indeterminate resistance profile, and in 48 (8.6%) samples, N. gonorrhoeae was not detected. Ciprofloxacin was prescribed in 172 (75%) of 228 episodes in which the wild-type strain was detected. Four (2%) of those treated with ciprofloxacin had a positive test-of-cure sample by NAAT, with no reinfection risk. All four had ciprofloxacin-susceptible infection by phenotypic antimicrobial susceptibility testing.

Conclusions: In routine practice in a large UK clinic, molecular ciprofloxacin resistance testing led to a significant shift in antibiotic use, reducing use of ceftriaxone. Testing can be targeted to reduce unnecessary additional testing. Longer term impact on antimicrobial resistance requires ongoing surveillance.

Keywords: CIPROFLOXACIN; Drug Resistance, Bacterial; Gonorrhea; Molecular Diagnostic Techniques; NEISSERIA GONORRHOEAE.