title: Decreased susceptibility of Neisseria gonorrhoeae isolates from Switzerland to Cefixime and Ceftriaxone: antimicrobial susceptibility data from 1990 and 2000 to 2012.
abstract: BACKGROUND
  Neisseria gonorrhoeae can rapidly develop resistance to antimicrobial agents. Over the last years, decreased gonococcal susceptibility to third-generation cephalosporins, especially cefixime, emerged worldwide. Therefore, current international guidelines recommend dual therapy for gonorrhoea with ceftriaxone plus either azithromycin or doxycycline. Gonococcal susceptibility data in Switzerland are sparse.
  
  
  METHODS
  We investigated the prevalence of antibiotic susceptibility of N. gonorrhoeae in specimens collected between 1990 and 2012 at the University of Zurich, Switzerland. Minimum inhibitory concentrations (MICs) for cefixime, ceftriaxone, ciprofloxacin, and penicillin were determined by Etests. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints were used to define reduced susceptibility.
  
  
  RESULTS
  A total of 320 isolates were tested. Between 1990 and 2006 all tested samples were susceptible to both cephalosporins. Subsequently, the prevalence of elevated MICs for cefixime increased to 10.4% (2007/2008), 11.5% (2009/2010), and 11.4% (2011/2012); and for ceftriaxone to 2.4% (2007/2008), 4.7% (2009/2010), and 0% (2011/2012), respectively. The prevalence of resistance to ciprofloxacin (72.7%) and penicillin (22.7%) was high in 2011/2012.
  
  
  CONCLUSIONS
  Decreasing susceptibility of N. gonorrhoeae to third-generation cephalosporins in Switzerland supports treatment recommendations with ceftriaxone plus azithromycin or doxycycline. Health-care providers need to be aware of possible treatment failures with cephalosporins. Continued surveillance of gonococcal antimicrobial resistance is essential.
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland. helen.kovari@usz.ch.
authors.forename: Helen
authors.initials: H
authors.lastname: Kovari
authors.forename: Maria Dg
authors.initials: MD
authors.lastname: de Melo Oliveira
authors.forename: Paula
authors.initials: P
authors.lastname: Hauser
authors.forename: Severin
authors.initials: S
authors.lastname: Läuchli
authors.forename: Jürg
authors.initials: J
authors.lastname: Meyer
authors.forename: Rainer
authors.initials: R
authors.lastname: Weber
authors.forename: Reinhard
authors.initials: R
authors.lastname: Zbinden
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology; D020682:Cefixime / Q000494:pharmacology*; D002443:Ceftriaxone / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology; D002939:Ciprofloxacin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D005260:Female; D006069:Gonorrhea / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009344:Neisseria gonorrhoeae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D013557:Switzerland / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D002939:Ciprofloxacin; D002443:Ceftriaxone; D017963:Azithromycin; D020682:Cefixime