Genetic and Antigenic Analysis of Invasive Serogroup C Neisseria meningitidis in Canada: A Decrease in the Electrophoretic Type (Et)-15 Clonal Type and an Increase in the Proportion of Isolates Belonging to the Et-37 (But Not Et-15) Clonal Type During the Period from 2002 to 2009. Issue 3 (2012)

• Record Type: Journal Article
• Authors: Zhou, Jianwei; Jamieson, Frances; Dolman, Sharon; Hoang, Linda MN; Rawte, Prasad; Tsang, Raymond SW
• Is Part Of: Canadian journal of infectious diseases & medical microbiology =. Volume 23:Issue 3(2012)
• Page Start: e55
• Page End: e59
• Publication Date: 2012
• Subjects: ET-15 -- ET-37 -- Meningococci -- Serogroup C; Communicable diseases -- Periodicals; Infection -- Periodicals; Communicable diseases; Infection; Communicable Diseases; Communicable Disease Control; Electronic journals; Periodicals; Fulltext; Internet Resources; Periodicals; 616.9
• DOI: 10.1155/2012/131328
• Languages: English
• ISSNs: 1712-9532

Abstract

Abstract : BACKGROUND: Serogroup C meningococcal disease has been endemic in Canada since the early 1990s, with periods of hyperendemic disease documented in the past two decades. The present study characterized invasive serogroup C meningococci in Canada during the period from 2002 to 2009. METHODS: Serogroup C meningococci were serotyped using monoclonal antibodies. Their clonal types were identified by either multilocus enzyme electrophoresis or multilocus sequence typing. RESULTS: The number of invasive serogroup C Neisseria meningitidis isolates received at the National Microbiology Laboratory (Winnipeg, Manitoba) for characterization has dropped from a high of 173 isolates in 2001 to just 17 in 2009, possibly related to the introduction of the serogroup C meningococcal conjugate vaccine. Before 2006, 80% to 95% of all invasive serogroup C meningococci belonged to the electrophoreic type (ET)-15 clonal type, and the ET-37 (but not ET-15) type only accounted for up to 5% of all isolates. However, beginning in 2006, the percentage of the ET-15 clonal type decreased while the ET-37 (but not ET-15) type increased from 27% in 2006 to 52% in 2009. The percentage of invasive serogroup C isolates not belonging to either ET-15 or ET-37 also increased. Most ET-15 isolates expressed the antigenic formula of C:2a:P1.7, 1 or C:2a:P1.5. In contrast, the ET-37 (but not ET-15) isolates mostly expressed the antigens of C:2a:P1.5, 2 or C:2a:P1.2. CONCLUSION: A shift in the antigenic and clonal type of invasive serogroup C meningococi was noted. This finding suggests vigilance in the surveillance of meningoccocal disease is warranted.