Distribution characteristics of nalP gene of Neisseria meningitidisin China

Objective To investigate the distribution characteristics of the nalP gene of Neisseria meningitidesin China.

Methods Multi locus Sequence Typing was used to analyze the molecular subtyping of the 187 N. meningitides isolates. Homologous comparison and clustering analysis were conductexd after obtaining the nalP gene and its flanking sequences from the whole genome sequences.

Results A total of 178 isolates of N. meningitides were nalP positive. The homology of nalP gene of N. meningitides and N. gonorrhoeae was 95%–96%, but they were split in two disparate branch, the homology of the flanking region ofnalP was more than 85%. Six of the 9 nalP– negative strains were ∆nalP2 and 3 new type of arrangement were found. The difference in phase on number between invasiveN. meningitides C strains and healthy carriage strains was statistically significant.

Conclusion The nalPgene ofN. meningitides might be obtained from N. gonorrheae and then has evolution independently. It is possibly that nalP negative strain has lost nalP gene. The invasive N. meningitides C strains which could express nalP might be in deficiency of the compensating mechanism.