Objectives: To reveal the population structure of invasive Neisseria meningitidis isolates after the initiation of an A + C vaccination program in China.
Methods: Multilocus sequence typing (MLST) and PorA typing were used to characterize 238 invasive N. meningitidis isolates collected in China between 2005 and 2012.
Results: During this period, sequence type (ST)-5, ST-4821 and ST-11 complexes were dominant among serogroups A, C and W, accounting for 100%, 98.5% and 100% of each serogroup, respectively. P1.20,9, P1.7-2,14 and P1.5,2 were the dominant PorA types of serogroups A, C and W, respectively. Serogroup B showed high genetic diversity with two dominant lineages: ST-4821 complex and ST-5662 subgroup.
Conclusions: The population of 238 invasive N. meningitidis isolates was primarily composed of a select group of recognized hypervirulent lineages. Among these clonal complexes, ST-7 serogroup A and ST-11 serogroup W are distributed globally, and other three clones exist only in China.
Keywords: Neisseria meningitidis; Polysaccharide-based meningococcal vaccine; Population structure; ST-11; ST-4821; ST-7.
Copyright © 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved.