Neisseria gonorrhoeae Multiantigen Sequence Typing Is Beneficial in Further Characterizing Gonococcal Populations in Alberta, Canada Ameeta E. Singh, BMBS, MSc,* Jennifer Gratrix, RN, MSc,Þ Ron Read, MD,þ Marguerite Lovgren, MLT, ART,§ Steven J. Drews, PhD,¶ Barbara Romanowski, MD,|| Karen Sutherland, RN, MA,Þ James Talbot, MD, PhD,** and Irene Martin, BScÞÞ Background: Antimicrobial resistance testing and behavioral data combined with Neisseria gonorrhoeae multiantigen sequence typing (NG-MAST) can help to define gonococcal populations and identify, characterize, and compare clusters of infection. Methods: Antimicrobial resistance testing, using E test, was reviewed for gonococcal isolates in Alberta, Canada, from 2007 to 2011. Anti- microbial resistance testing was conducted on isolates demonstrating antimicrobial resistance and those with cefixime minimum inhibitory concentrations (MICs) of 0.06 Kg/mL or greater. Demographic and be- havioral information was obtained from provincial surveillance data. NG-MAST typing was conducted on a proportion of isolates. Results: Gonococcal isolates were available for 2250 (26.4%) of 8535 cases of gonorrhea in Alberta from 2007 to 2011. The proportion of cases with decreased susceptibility to cefixime (Q0.06 Kg/mL) in- creased from 0.7% to 2.4% between 2007 and 2009 to a high of 10.1% in 2010 and 8.9% in 2011. Six isolates with cefixime MIC of 0.25 Kg/mL were noted: 5 were from men who have sex with men (MSM) and 1 was a pharyngeal isolate from a heterosexual female. Twenty-four (1.1%) iso- lates were azithromycin resistant (MIC Q2.0 Kg/mL); there were no sig- nificant differences between cases resistant or susceptible to azithromycin. NG-MAST of gonococcal isolates in Alberta suggests the entry of mul- tiple strains into the province. Three clusters were identified: Cluster A predominantly in MSM, including sequence type 1407, a ST previously associated with decreased susceptibility to expanded spectrum cepha- losporins; Cluster B, a predominantly heterosexual cluster with most cases in Edmonton; and Cluster C among MSM. Conclusions: Our data highlight the use of NG-MAST in further de- fining gonococcal populations. T he incidence of gonorrhea has been increasing in Canada since 1998, and it is the second most commonly reported sexually transmitted infection (STI). 1 Between 1997 and 2010, the reported number and rate of gonococcal infections in Canada more than doubled from 4468 (14.9 per 100,000) to 11,397 (33.4 per 100,000) cases. 1 Untreated gonorrhea can result in significant morbidity and mortality such as pelvic inflammatory disease, infertility, enhanced HIV transmission, ophthalmic infections, and first- trimester spontaneous abortions. 2 Identification of cases and effective treatment remains the mainstay of prevention and control but challenging this goal is the rapid development and acqui- sition of antimicrobial resistance (AMR) in Neisseria gonorrhoeae (NG) via a variety of mechanisms 3 as well as how this infection is transmitted within and between sexual networks. 4 In Alberta, Canada, ciprofloxacin was the first-line rec- ommended treatment of gonorrhea from 1991 until the emer- gence of increasing cases of ciprofloxacin resistance in 2005. 5 In 2007, the first-line recommended treatment was changed to single-dose oral cefixime 400 mg. Recent global and national reports of rising minimum inhibitory concentration (MIC) to ex- panded spectrum cephalosporins (ESCs) prompted a closer re- view of data obtained through the provincial surveillance system. Standard surveillance included review of epidemiologic and sus- ceptibility testing data only. However, new methods have been developed and applied to phenotypically and genotypically char- acterize NG isolates. 6 N. gonorrhoeae multiantigen sequence typing (NG-MAST) examines the variable internal fragments of 2 highly polymorphic loci of NG and has high discriminatory power, high reproducibility, and typeability. It has been widely used through the availability of a public database that can be accessed for analysis and for the assignment of discrete allele numbers and sequence types (STs). 6 The purpose of this study was to incorporate NG-MAST into the review of our surveil- lance data, including AMR data, to help define gonococcal populations and to identify clusters of infection and the role of particular strains. MATERIALS AND METHODS Gonorrhea is a notifiable disease in both Canada and the province of Alberta. Alberta is a province of approximately 3 million people, with two thirds of the population living in 2 large urban centers (Edmonton and Calgary). As part of the notifiable disease reporting guidelines, all gonorrhea cases are to be reported to the provincial STI Services. Testing providers complete a notification form that includes information on de- mographics, exposure risks, and contact information of recent sexual partners. Antimicrobial resistance is monitored mainly through 2 sentinel sites in Alberta (ie, Alberta Health Services, Edmonton and Calgary STI Clinics). Cultures for NG collected at these 2 clinics are directly inoculated on selective Thayer Martin media and transported daily to 2 Provincial Laboratory for Public Health (ProvLab) sites located in Edmonton and Calgary. Additional cultures are obtained by testing providers ORIGINAL STUDY 744 Sexually Transmitted Diseases & Volume 40, Number 9, September 2013 From the *Edmonton STI Clinic and †STI Services, Alberta Health Ser- vices, Edmonton, Alberta, Canada; ‡Calgary STI Clinic, Alberta Health Services, Calgary, Alberta, Canada; §Provincial Laboratory for Public Health, Edmonton, Alberta, Canada; ¶Provincial Laboratory for Public Health, Calgary, Alberta, Canada; ||University of Alberta, Edmonton, Alberta, Canada; **Alberta Health, Edmonton, Alberta, Canada; and ††National Microbiology Laboratory, Winnipeg, Manitoba, Canada Acknowledgments: The authors wish to acknowledge manuscript re- view by other members of the Alberta Gonorrhea Antimicrobial Surveillance Working Group: J. Bergman, D. Gregson, C. Egan, K. Simmonds, and K. Zhang. The authors have declared no conflict of interest; this work was unfunded. Correspondence: Ameeta Singh, BMBS, MSc, University of Alberta, 3B20-11111 Jasper Ave, Edmonton AB. T5K 0L4, Canada 3B20- 11111. E-mail: ameeta@ualberta.ca. Received for publication February 12, 2013, and accepted May 14, 2013. DOI: 10.1097/01.olq.0000431356.80840.d4 Copyright * 2013 American Sexually Transmitted Diseases Association All rights reserved. Copyright © 2013 by the American Sexually Transmitted Diseases Association. Unauthorized reproduction of this article is prohibited.