(P69) Reduced susceptibility of pharyngeal Neisseria gonorrhoeae infections to current recommended therapeutics in England and Wales using national surveillance data (GRASP)

Background:

Neisseria gonorrhoeae (NG) infection in the pharynx is more difficult to treat than infections at other sites, possibly due to poor tissue penetration of antimicrobials at this site. Persistent NG infection may develop antimicrobial resistance by genetic exchange of resistance determinants with commensal Neisseria species in the pharynx. Using data between 2012-2020 from the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP), we investigated the association between anatomical site of infection and reduced susceptibility or resistance to therapeutically relevant antimicrobials among NG positive individuals attending sexual health services in England and Wales.

Methods:

Multivariate logistic regression was used to investigate the association between site of infection (pharyngeal vs genital, pharyngeal vs rectal) and resistance (R) (EUCAST breakpoints) or reduced susceptibility (RS) (defined where resistance was rare) to azithromycin (R at minimum inhibitory concentration (MIC) >0.5 mg/L), ceftriaxone (RS at both MIC >0.015 mg/L and MIC >0.03 mg/L), cefixime (RS at MIC >0.06 mg/L; R at MIC >0.125 mg/L) and ciprofloxacin (R at MIC >0.06 mg/L) among gay, bisexual and other men who have sex with men (GBMSM) and heterosexual women.

Results:

A total of 10,275 NG isolates were included, of which 8,402 (82%) were from GBMSM and 1,873 (18%) from heterosexual women. Pharyngeal isolates comprised 13% of isolates from GBMSM and 6% from heterosexual women. Pharyngeal infections were significantly associated with RS to ceftriaxone (MIC >0.03 mg/L) compared to both genital (aOR: 1.76, p=0.009) and rectal infections (aOR: 2.15, p< 0.001) among GBMSM. Among heterosexual women, pharyngeal infections were associated with RS to ceftriaxone (MIC >0.015 mg/L) (aOR: 1.93, p=0.03) and RS to cefixime (aOR: 2.49, p=0.03) compared to genital infections. No other associations were found.

Conclusion:

Ceftriaxone resistance remains rare in the UK and no resistance has been detected through GRASP. However pharyngeal isolates from both GBMSM and heterosexual women were more likely to have RS to ceftriaxone than isolates from other sites. These findings emphasise the importance of extra-genital testing, access to susceptibility testing and test of cure to prevent the possibility of widespread treatment failures. Additionally, surveillance programmes should consider prioritising collection of isolates from pharyngeal infections.