title: Persistence of Neisseria gonorrhoeae DNA following treatment for pharyngeal and rectal gonorrhea is influenced by antibiotic susceptibility and reinfection.
abstract: BACKGROUND
  To guide interpretation of gonorrhea tests of cure using nucleic acid amplification testing, this study examined the persistence of Neisseria gonorrhoeae DNA following treatment for pharyngeal and rectal gonorrhea.
  
  
  METHODS
  Men who had sex with men diagnosed with pharyngeal or rectal gonorrhea underwent swabbing from the pharynx or rectum 7 and 14 days following treatment. Repeat testing for N. gonorrhoeae was undertaken using real-time polymerase chain reaction (PCR) assays targeting the opa gene and porA pseudogene.
  
  
  RESULTS
  One hundred pharyngeal and 100 rectal gonorrhea infections in 190 men were included. For pharyngeal gonorrhea, positivity of N. gonorrhoeae DNA on both PCR assays was present at days 7 or 14 in 13% (95% confidence interval [CI], 6.4%-19.6%) and 8% (95% CI, 2.7%-13.3%), respectively. For rectal gonorrhea, DNA positivity was present in 6% (95% CI, 1.4%-10.7%) and 8% (95% CI, 2.7%-13.3%), respectively. Among 200 baseline pharyngeal and rectal isolates, there were 10 with ceftriaxone minimum inhibitory concentration (MIC) ≥0.06 mg/L and azithromycin MIC ≥0.5 mg/L, of which 3 (30%) had DNA detected at day 14; among the 190 isolates with lower ceftriaxone and azithromycin MICs, only 13 (7%) had persistent DNA (odds ratio, 5.8 [95% CI, 1.3-25.4]; P = .019). One man initially infected with N. gonorrhoeae multiantigen sequence type 2400 had type 4244 infection at day 14, indicating reinfection.
  
  
  CONCLUSIONS
  Pharyngeal and rectal gonorrhea DNA persisted in 8% of men 14 days after treatment. Persistence was associated with elevated ceftriaxone and azithromycin MICs. Persistence can also reflect reinfection.
authors.affiliation: Melbourne Sexual Health Centre Melbourne School of Population and Global Health, University of Melbourne, Victoria.
authors.forename: Melanie
authors.initials: M
authors.lastname: Bissessor
authors.affiliation: The University of Queensland, St Lucia Queensland Paediatric Infectious Diseases Laboratory, Royal Children's Hospital, Herston.
authors.forename: David M
authors.initials: DM
authors.lastname: Whiley
authors.affiliation: Melbourne Sexual Health Centre Central Clinical School, Monash University, Melbourne, Victoria.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Fairley
authors.affiliation: Melbourne Sexual Health Centre Central Clinical School, Monash University, Melbourne, Victoria.
authors.forename: Catriona S
authors.initials: CS
authors.lastname: Bradshaw
authors.affiliation: Melbourne Sexual Health Centre.
authors.forename: David M
authors.initials: DM
authors.lastname: Lee
authors.affiliation: Melbourne Sexual Health Centre.
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Snow
authors.affiliation: World Health Organization Collaborating Centre for Sexually Transmitted Diseases, SEALS Microbiology, The Prince of Wales Hospital, Randwick University of New South Wales, Kensington, Australia.
authors.forename: Monica M
authors.initials: MM
authors.lastname: Lahra
authors.affiliation: Melbourne School of Population and Global Health, University of Melbourne, Victoria.
authors.forename: Jane S
authors.initials: JS
authors.lastname: Hocking
authors.affiliation: Melbourne Sexual Health Centre Central Clinical School, Monash University, Melbourne, Victoria.
authors.forename: Marcus Y
authors.initials: MY
authors.lastname: Chen
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D017963:Azithromycin / Q000627:therapeutic use; D058491:Bacterial Load; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D002443:Ceftriaxone / Q000627:therapeutic use; D004247:DNA / Q000302:isolation & purification*; D006069:Gonorrhea / Q000188:drug therapy* / Q000382:microbiology; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009344:Neisseria gonorrhoeae / Q000235:genetics / Q000302:isolation & purification*; D021141:Nucleic Acid Amplification Techniques; D010608:Pharyngeal Diseases / Q000188:drug therapy* / Q000382:microbiology; D010614:Pharynx / Q000382:microbiology; D018272:Porins / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012002:Rectal Diseases / Q000188:drug therapy* / Q000382:microbiology; D012007:Rectum / Q000382:microbiology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D018272:Porins; C057699:porin protein, Neisseria; C090348:Opa protein, Neisseria; D002443:Ceftriaxone; D017963:Azithromycin; D004247:DNA
keywords: gonorrhea; minimum inhibitory concentration of antibiotics; persistent DNA on NAAT testing; reinfection; test of cure