Distribution of surface-protein variants of hyperinvasive meningococci in China.

OBJECTIVE

Information regarding the different types of FetA and PorB meningococci that circulate in various regions of the world is still scarce. The present study investigated the distribution of FetA and PorB variable region (VR) types among meningococci belonging to hyperinvasive lineages circulating in China.

METHODS

The approach consisted of genotypic analysis of 201 Neisseria meningitidis strains belonging to hyperinvasive lineages isolated in China during the period 1956-2006.

RESULTS

Sixteen different PorB types were found, 8 of which were newly identified. Of the 24 different FetA VR types, 3 were determined to be novel. Particular combinations of FetA and PorB types associated with distinct clonal complexes were also observed. Most cases of invasive disease were caused by five individual clones: A: P1.7-1,10: F5-5: ST-3 (cc1) with P3.6,11,10,7 (class 3 PorB protein; VR1-6, VR2-11, VR3-10, and VR4-7); A: P1.20,9: F3-1: ST-5 (cc5) with P3.4,11,10,7; A: P1.20,9: F3-1: ST-5 (cc5) with P3.9,11,10,7; A: P1.20,9: F3-1: ST-7 (cc5) with P3.4,11,10,7; and C: P1.7-2,14: F3-3: ST-4821 (cc4821) with P3.9,15,6,7.

CONCLUSION

A number of antigen-gene variants and combinations exhibited broad temporal and geographic distributions, although several invasive clones were mainly associated with a specified timeframe. The changes that are increasingly emerging in circulating strains and the prevalent clone replacement describe the molecular epidemiology of meningococcal disease in China. Our findings have implications for both public-health monitoring and further study of this organism.