Analysis on molecular epidemiological characteristics of Neisseria meningitidis in Suzhou, Jiangsu, 2011–2016

Objective To understand the serogroup and molecular epidemiological characteristics of Neisseria meningitidis isolated from patients, close contacts and healthy carriers in Suzhou during 2011–2013.

Methods Latex agglutination test and multi locus sequence typing (MLST) were conducted to identify the serogroups and sequences of 7 housekeeping genes of 33 strains of N. meningitidis isolated in Suzhou during 2011–2013. The sequence alignment was conducted by using PubMLST database and the allelic profile and sequence types were determined. Software Cluster 3.0 was used in analyzing genetic evolution of the strains.

Results Among the N. meningitidis strains isolated, 22 were serogroup B strains (66.67%), 8 were serogroup W135 strains (24.24%), 1 was serogroup C strain (3.03%) 1 was serogroup Y strains (3.03%) and 1 was unspecified (3.03%). Three serogroup W135 strains isolated in 2011 belonged to highly pathogenic ST-11 complex/ET-37 complex and 5 serogroup B strains isolated during 2012–2013 belonged to highly pathogenic ST-4821complex.

Conclusion N. meningitidis B was predominant, followed by N. meningitidis W135, in Suzhou during 2011–2016. Multiple clonal complexes existed. Highly pathogenic serogroup W135 strains belonging to ST-11 complex/ET-37 complex and serogroup B strains belonging to ST-4821 complex have appeared in Suzhou, suggesting the importance of strengthening the surveillance to prevent and control the outbreak of meningococcal meningitis.