title: One confirmed and one suspected case of pharyngeal gonorrhoea treatment failure following 500mg ceftriaxone in Sydney, Australia.
abstract: Emerging antimicrobial resistance within Neisseria gonorrhoeae (NG) is a significant global public health threat. Detection and investigation of treatment failures is a crucial component of the World Health Organisation's response to this challenge. We report the cases of two homosexual men, both treated for pharyngeal NG with 500mg intramuscular ceftriaxone, in whom a test of cure 1 week after treatment showed persisting infection. Both men denied further sexual activity. In the first case, treatment failure was confirmed, since the isolates before and after treatment were identical by auxotype, antibiogram, multilocus sequence type (MLST) and multi-antigen sequence type (NG-MAST). In the second case, the MLSTs before and after treatment were identical, but NG-MAST results were similar but not indistinguishable. These cases underline the importance of test-of-cure and molecular investigations in identifying treatment failure, but also highlight the complexity of distinguishing treatment failure from reinfection when relying on highly variable molecular targets that may be subject to drug pressure.
authors.affiliation: Sydney Sexual Health Centre, GPO Box 1614, Sydney, NSW 2001, Australia.
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Read
authors.forename: E Athena
authors.initials: EA
authors.lastname: Limnios
authors.forename: Anna
authors.initials: A
authors.lastname: McNulty
authors.forename: David
authors.initials: D
authors.lastname: Whiley
authors.forename: Monica M
authors.initials: MM
authors.lastname: Lahra
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001315:Australia; D002443:Ceftriaxone / Q000627:therapeutic use*; D006069:Gonorrhea / Q000188:drug therapy*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D010608:Pharyngeal Diseases / Q000188:drug therapy*; D017211:Treatment Failure; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D002443:Ceftriaxone