title: Molecular epidemiology of Neisseria gonorrhoeae isolates from Saskatchewan, Canada: utility of NG-MAST in predicting antimicrobial susceptibility regionally.
abstract: OBJECTIVE
  To investigate the molecular epidemiology of isolates of Neisseria gonorrhoeae from Saskatchewan, Canada, using Neisseria gonorrhoeae multi antigen sequence typing (NG-MAST), and to assess associations between antimicrobial susceptibility (AMS) and specific strain types (STs).
  
  
  METHODS
  320 consecutive gonococcal isolates, collected between 2003 and 2008, were typed by NG-MAST. STs were grouped if one of their alleles was common and the other differed by ≤1% in DNA sequence. AMS was determined by agar dilution (CLSI) to seven antibiotics.
  
  
  RESULTS
  N gonorrhoeae isolates were resolved into 82 individual NG-MAST STs and 18 NG-MAST ST groups with groups 25, 3655, 921, 3654, 3657 and 3656 comprising 53.4% (171/320) of the isolates. N gonorrhoeae isolates susceptible to all the tested antimicrobials were significantly (p<0.05) associated with ST 25 (87%). Other significant associations between ST and AMS included: ST 3654 and isolates with minimum inhibitory concentrations of ≥0.03 mg/L to third generation cephalosporins; ST 3711 (100%) and TRNG; and ST/group 3654 (43%) and chromosomal resistance to penicillin and tetracycline. Several NG-MAST STs/groups were significantly associated with isolates with chromosomal resistance to tetracycline. Isolates resistant to ciprofloxacin (n=5) and azithromycin (n=2) appeared as individual STs. Significant associations were observed among individual STs, sex and age of the patient, and regional and temporal distributions.
  
  
  CONCLUSIONS
  Associations between N gonorrhoeae AMS and NG-MAST STs were identified and may be useful in predicting AMS regionally. Because STs in different countries vary considerably, the use of NG-MAST for the prediction of AMS globally requires further study.
authors: Department of Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors: Sidharath D
authors: SD
authors: Thakur
authors: Saskatchewan Disease Control Laboratory, Regina, Saskatchewan, Canada.
authors: Paul N
authors: PN
authors: Levett
authors: Saskatchewan Disease Control Laboratory, Regina, Saskatchewan, Canada.
authors: Gregory B
authors: GB
authors: Horsman
authors: Department of Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatchewan, Canada.
authors: Jo-Anne R
authors: JA
authors: Dillon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017963:Azithromycin / Q000494:pharmacology; D015373:Bacterial Typing Techniques / Q000379:methods; D020682:Cefixime / Q000494:pharmacology; D002443:Ceftriaxone / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D002939:Ciprofloxacin / Q000494:pharmacology; D004269:DNA, Bacterial / Q000032:analysis*; D005260:Female; D006069:Gonorrhea / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D058889:Molecular Typing / Q000379:methods; D009344:Neisseria gonorrhoeae / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D010406:Penicillins / Q000494:pharmacology; D012525:Saskatchewan / Q000453:epidemiology; D017422:Sequence Analysis, DNA / Q000379:methods; D000198:Spectinomycin / Q000494:pharmacology; D013752:Tetracycline / Q000494:pharmacology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D010406:Penicillins; D002939:Ciprofloxacin; D002443:Ceftriaxone; D017963:Azithromycin; D000198:Spectinomycin; D020682:Cefixime; D013752:Tetracycline
keywords: Antibiotic Sensitivity; Molecular Epidemiology; Molecular Typing; Neisseria Gonorrhoea