Resistant gonorrhoea: east meets west

Abstract

In 2016 and 2018, two treatment failures of ceftriaxone and azithromycin, used in combination, were reported in the UK in men who contracted gonococcal infections in Asia,1, 2 once again suggesting that antimicrobial resistance of Neisseria gonorrhoeae is spreading. These treatment failures indicate the potentially waning efficacy and usefulness of this combination, which is currently recommended as the first-line therapy. Surveillance of antimicrobial resistance is paramount if resistance patterns of these and other antimicrobials are to be recognised in a timely manner that enables meaningful intervention and prevention of the spread of resistant organisms. Antimicrobial susceptibility testing (phenotyping) for antimicrobial resistance is considered the gold-standard test. There are some key limitations to the more commonly used methods of genotyping, such as N gonorrhoeae multi-antigen sequence typing (NG-MAST) and multilocus sequence typing (MLST), which indicate associated antimicrobial resistance determinants but do not directly identify antimicrobial resistance. The genotypes of N gonorrhoeae strains that are identified by use of these methods, which include antimicrobial resistance determinants, often do not correlate directly with the mean inhibitory concentrations of antimicrobials against these strains.