Amino acid sequences from
strains. Note: (IB3), (IB3/6), (IB2) and (IB4): reported PorB1B sequences belonging to serotypes IB3 (GenBank accession No: U75639), IB3/6 (GenBank accession No: U75641), IB2 (GenBank No: U75640) and IB4 (GenBank No: AF090797), respectively; (1): PorB1B sequence from 58 gonococcal isolates referring to IB3 serotype; (2): PorB1B sequence from 49 gonococcal isolates referring to IB3/6 serotype (D means the 27 isolates with A121D mutation, the 19 isolates with A121G mutation and the remaining 3 isolates with no mutation at the A121 site); (3): PorB1B sequence from 62 gonococcal isolates referring to IB3/6-IB2 chimeric serotype without A121 and N122 deletion (K means the 53 strains with G120K mutation and the remaining 9 strains with G120N mutation); (4): PorB1B sequence from 15 gonococcal isolates referring to IB3/6-IB2 chimeric serotype with A121 and N122 deletions; (5): PorB1B sequence from 25 gonococcal isolates referring to IB4 serotype; (6): PorB1B sequence from 8 gonococcal isolates referring to IB2-IB4-IB2 chimeric serotype. Underlined areas indicate the positions of primers. The signal "/" means lack of the amino acid residue.