title: Trends in antimicrobial susceptibility for azithromycin and ceftriaxone in Neisseria gonorrhoeae isolates in Amsterdam, the Netherlands, between 2012 and 2015.
abstract: Resistance of Neisseria gonorrhoeae to azithromycin and ceftriaxone has been increasing in the past years. This is of concern since the combination of these antimicrobials is recommended as the first-line treatment option in most guidelines. To analyse trends in antimicrobial resistance, we retrospectively selected all consultations with a positive N. gonorrhoeae culture at the sexually transmitted infection clinic, Amsterdam, the Netherlands, from January 2012 through September 2015. Minimum inhibitory concentrations (MICs) for azithromycin and ceftriaxone were analysed per year, and determinants associated with decreased susceptibility to azithromycin (MIC > 0.25 mg/L) or ceftriaxone (MIC > 0.032 mg/L) were assessed. Between 2012 and 2015 azithromycin resistance (MIC > 0.5 mg/L) was around 1.2%, the percentage of isolates with intermediate MICs (> 0.25 and ≤ 0.5 mg/L) increased from 3.7% in 2012, to 8.6% in 2015. Determinants associated with decreased azithromycin susceptibility were, for men who have sex with men (MSM), infections diagnosed in the year 2014, two infected sites, and HIV status (HIV; associated with less decreased susceptibility); for heterosexuals this was having ≥ 10 sex partners (in previous six months). Although no ceftriaxone resistance (MIC > 0.125 mg/L) was observed during the study period, the proportion of isolates with decreased ceftriaxone susceptibility increased from 3.6% in 2012, to 8.4% in 2015. Determinants associated with decreased ceftriaxone susceptibility were, for MSM, infections diagnosed in 2014, and pharyngeal infections; and for heterosexuals, infections diagnosed in 2014 or 2015, being of female sex, and having ≥ 10 sex partners. Continued decrease of azithromycin and ceftriaxone susceptibility will threaten future treatment of gonorrhoea. Therefore, new treatment strategies are warranted.
authors.affiliation: STI Outpatient Clinic, Department of Infectious Diseases Public Health Service Amsterdam, Amsterdam, the Netherlands.|Department of Dermatology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Carolien M
authors.initials: CM
authors.lastname: Wind
authors.affiliation: Department of Infectious Diseases, Public Health Service Amsterdam, Amsterdam, the Netherlands.|Center for Infection and Immunity Amsterdam, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Maarten F
authors.initials: MF
authors.lastname: Schim van der Loeff
authors.affiliation: Public Health Laboratory, Public Health Service Amsterdam, Amsterdam, the Netherlands.|Department of Medical Microbiology, Onze Lieve Vrouwe Gasthuis General Hospital, Amsterdam, the Netherlands.
authors.forename: Alje P
authors.initials: AP
authors.lastname: van Dam
authors.affiliation: STI Outpatient Clinic, Department of Infectious Diseases Public Health Service Amsterdam, Amsterdam, the Netherlands.|Department of Dermatology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.|Center for Infection and Immunity Amsterdam, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Henry Jc
authors.initials: HJ
authors.lastname: de Vries
authors.affiliation: STI Outpatient Clinic, Department of Infectious Diseases Public Health Service Amsterdam, Amsterdam, the Netherlands.|Department of Infectious Diseases, Public Health Service Amsterdam, Amsterdam, the Netherlands.
authors.forename: Jannie J
authors.initials: JJ
authors.lastname: van der Helm
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D017963:Azithromycin / Q000494:pharmacology* / Q000627:therapeutic use; D002443:Ceftriaxone / Q000494:pharmacology* / Q000627:therapeutic use; D024881:Drug Resistance, Bacterial; D005260:Female; D006069:Gonorrhea / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests / Q000639:trends; D008875:Middle Aged; D009344:Neisseria gonorrhoeae / Q000187:drug effects* / Q000302:isolation & purification; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D017678:Sex Distribution; D019529:Sexuality; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D002443:Ceftriaxone; D017963:Azithromycin
keywords: Neisseria gonorrhoeae; antimicrobial resistance; azithromycin; ceftriaxone; susceptibility