Abstract: Objective To compare the potentiality of opa typing versus Neisseria gonorrhoeae multi- antigen sequence typing （Ng-MAST） in discrimination of N. gonorrhoeae isolates, and to investigate the consistency of genotypes of N. gonorrhoeae between patients and their sex partners. Methods N. gonorrhoeae was isolated from patients and their sex partners who attended sexually transmitted disease clinics of the Affiliated Union Hospital of Tongji Medical College, Huazhong University of Science and Technology from February 2006 to August 2007. All isolates were cultured on Thayer-Martin agar and GC-based chocolate agar, and identified by Gram stain and oxidase reaction. Totally, twenty-four strains of N. gonorrhoeae were isolated form 12 pairs of male-female sex partners. Genomic DNA was isolated form the strains, and subjected to PCR amplification of opa gene as well as por and tbpB genes. opa typing and Ng-MAST typing were utilized to differentiate the 24 strains respectively. Results The 24 isolates were classified into 10 sequence types （ST） by Ng-MAST typing, and 12 opa types （OT） by opa typing. A novel genotype identified by Ng-MAST（217-86% homologisation 178）, was unique in China. Conclusions Both ST and OT of N. gonorrhoeae strains are identical between patients and their corresponding partners except for one pair of partners, 45/46, suggesting that gonorrhea is transmitted to each other by contiguity between sex partners. Opa typing is likely to be more potential than Ng-MAST in genotyping of N.gonorrhoeae strains.

Key words: Neisseria gonorrhoeae, Genotype, NG-MAST