Neisseria gonorrhoeae multi antigen sequence typing (NG-MAST) groups based on porB and tbpB sequence similarity
| NG-MAST Group | n*(%) | Predominant ST (n) | STs which differ by ≤1% for | Significant association with resistance phenotypes | |
|---|---|---|---|---|---|
| porB† ST (n) | tbpB‡ ST (n) | ||||
| 25 | 52 (16.3) | 25 (46) | 51 (2), 70 (2), 4674 (2) | Susceptible§ | |
| 3655¶ | 35 (10.9) | 3655 (23) | 508§ (10), 3658 (2) | CMTR§ | |
| 921 | 27 (8.4) | 921 (13) | 3662 (2), 3666 (2), 3675 (1), 3712 (2), 3714 (7) | CMTR§ | |
| 3654 | 23 (7.2) | 3654 (21) | 4516 (1), 4670 (1) | CMRNG§ | |
| 3657 | 20 (6.3) | 3657 (15) | 3660 (2), 3677 (2), 3667 (1) | ||
| 3656¶ | 14 (4.4) | 3656 (13) | 4584 (1) | ||
| 3653 | 10 (3.1) | 3653 (8) | 3673 (2) | ||
| 12 | 10 (3.1) | 12 (4) | 238 (3), 3670 (3) | ||
| 3671 | 8 (2.5) | 3671 (7) | 3678 (1) | ||
| 210 | 8 (2.5) | 210 (5) | 3663 (3) | ||
| 1109 | 7 (2.2) | 1109 (4) | 3659 (2), 4711 (1) | ||
| 5 | 5 (1.5) | 5 (3) | 3485 (1), 4673 (1) | ||
| 3669 | 3 (0.9) | 3669 (2) | 3664 (1) | ||
| 4228 | 3 (0.9) | 4228 (2) | 1650 (1) | ||
| 3116 | 3 (0.9) | 3116 (2) | 3668 (1) | ||
| 4227 | 2 (0.6) | 4227 (1) | 4675 (1) | ||
| 225 | 2 (0.6) | 225 (1) | 4712 (1) | ||
| 64 | 2 (0.6) | 64 (1) | 359 (1) | ||
| Other individual STs or ungroupable STs (n=33) | 86 (26.9) | 0 | 0 | 0 | |
| Total | 320 | 233 | 61 | 4 | |
*ST groups comprise ≥2 isolates.
†STs that share an identical tbpB allele but porB allele varies by ≤1%.
‡STs that share an identical porB allele but tbpB allele varies by ≤1%.
§Significant association with ST group and AMS, p value (<0.05).
¶STs 3655 and 508 have ≤1% difference in their porB (356:2195) alleles and have identical tbpB allele (28). ST 508 also shared a porB (356) allele with ST 3656 and differed in its tbpB allele (28 : 821) by ≤1%. Since ST 3655 was more prevalent, ST 508 was placed in group 3655.
AMS, antimicrobial susceptibility; CMRNG, chromosomally resistant N gonorrhoeae; CMTR, chromosomally-mediated tetracycline resistance; ST, strain type.