title: Characterization of Neisseria gonorrhoeae isolates detected in Switzerland (1998-2012): emergence of multidrug-resistant clones less susceptible to cephalosporins.
abstract: BACKGROUND
  The spread of Neisseria gonorrhoeae (Ng) isolates resistant to the clinically implemented antibiotics is challenging the efficacy of treatments. Unfortunately, phenotypic and molecular data regarding Ng detected in Switzerland are scarce.
  
  
  METHODS
  We compared the characteristics of Ng detected during 1998-2001 (n = 26) to those detected during 2009-2012 (n = 34). MICs were obtained with the Etest and interpreted as non-susceptible (non-S) according to EUCAST criteria. Sequence type (ST) was achieved implementing the NG-MAST. BlaTEM, ponA, penA, mtrR, penB, tet(M), gyrA, parC, mefA, ermA/B/C/F, rplD, rplV, and 23S rRNA genes were analyzed.
  
  
  RESULTS
  The following susceptibility results were obtained (period: % of non-S, MIC90 in mg/L): penicillin (1998-2001: 42.3%, 3; 2009-2012: 85.3%, 16), cefixime (1998-2001: 0%, ≤0.016; 2009-2012: 8.8%, 0.125), ceftriaxone (1998-2001: 0%, 0.004; 2009-2012: 0%, 0.047), ciprofloxacin (1998-2001: 7.7%, 0.006; 2009-2012: 73.5%, ≥32), azithromycin (1998-2001: 11.5%, 0.25; 2009-2012: 23.6%, 0.38), tetracycline (1998-2001: 65.4%, 12; 2009-2012: 88.2%, 24), spectinomycin (1998-2001: 0%, 12; 2009-2012: 0%, 8). The prevalence of multidrug-resistant (MDR) isolates increased from 7.7% in 1998-2001 to 70.6% in 2009-2012. International STs and genogroups (G) emerged during 2009-2012 (G1407, 29.4%; G2992, 11.7%; G225, 8.8%). These isolates possessed distinctive mechanisms of resistance (e.g., G1407: PBP1 with L421, PBP2 pattern XXXIV, GyrA with S91F and D95G, ParC with S87R, PorB with G120K and A121N, mtrR promoter with A deletion).
  
  
  CONCLUSIONS
  The prevalence of penicillin- ciprofloxacin- and tetracycline-resistant Ng has reached dramatic levels, whereas cefixime and ceftriaxone show MICs that tend to increase during time. International MDR clones less susceptible to cephalosporins are rapidly emerging indicating that the era of untreatable gonococcal infections is close.
authors.affiliation: Institute for Infectious Diseases, University of Bern, Bern, Switzerland. aendimiani@gmail.com.
authors.forename: Andrea
authors.initials: A
authors.lastname: Endimiani
authors.forename: Yuvia N
authors.initials: YN
authors.lastname: Guilarte
authors.forename: Regula
authors.initials: R
authors.lastname: Tinguely
authors.forename: Lea
authors.initials: L
authors.lastname: Hirzberger
authors.forename: Sylvia
authors.initials: S
authors.lastname: Selvini
authors.forename: Agnese
authors.initials: A
authors.lastname: Lupo
authors.forename: Christoph
authors.initials: C
authors.lastname: Hauser
authors.forename: Hansjakob
authors.initials: H
authors.lastname: Furrer
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017963:Azithromycin; D020682:Cefixime / Q000494:pharmacology; D002443:Ceftriaxone / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D002939:Ciprofloxacin / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006069:Gonorrhea / Q000188:drug therapy* / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008826:Microbial Sensitivity Tests; D009344:Neisseria gonorrhoeae / Q000302:isolation & purification*; D010406:Penicillins / Q000494:pharmacology; D010641:Phenotype; D013557:Switzerland / Q000453:epidemiology; D013752:Tetracycline / Q000494:pharmacology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D010406:Penicillins; D002939:Ciprofloxacin; D002443:Ceftriaxone; D017963:Azithromycin; D020682:Cefixime; D013752:Tetracycline