title: Antigenic and genetic characterization of serogroup C meningococci isolated from invasive meningococcal disease cases in Canada from 1999 to 2003.
abstract: Four hundred and forty-two serogroup C Neisseria meningitidis isolates from individual invasive meningococcal disease (IMD) patients in Canada during the period 1999 to 2003 were analyzed. The majority (84%) of the serogroup C meningococci were characterized by the serotype antigen 2a and belonged to the clonal complex of electrophoretic type ET-15. However, after more than a decade of endemic disease as well as a number of outbreaks and many vaccination campaigns, both genetic and antigenic variants of the serogroup C serotype 2a meningococci were noted. Such variants include strains characterized as C:2a:P1.5 and C:2a:P1.7,1 as well as a non-serotypeable phenotype due to a mutational hot spot on the serotype 2a PorB outer-membrane protein. Meningococci characterized by the antigen formula B:2a:P1.5,2 and B:2a:P1.7,1 have also been found, which suggests capsule switching. Besides the clonal group of ET-15/ET-37, small numbers of serogroup C isolates were found to belong to the clonal complexes of ST-8 (Cluster A4), ST-41/44 (Lineage 3), ST-35, and ST-269.
authors.affiliation: Laboratory of Pathogenic Neisseria and Vaccine Preventable Bacterial Diseases, National Microbiology Laboratory, Canada.
authors.forename: Dennis K S
authors.initials: DK
authors.lastname: Law
authors.forename: Jan
authors.initials: J
authors.lastname: Stoltz
authors.forename: Averil M
authors.initials: AM
authors.lastname: Henderson
authors.forename: Raymond S W
authors.initials: RS
authors.lastname: Tsang
mesh_terms: D000595:Amino Acid Sequence; D000940:Antigenic Variation; D001483:Base Sequence; D014644:Genetic Variation; D006801:Humans; D015994:Incidence; D008589:Meningococcal Infections / Q000453:epidemiology / Q000382:microbiology; D008969:Molecular Sequence Data; D038542:Neisseria meningitidis, Serogroup C / Q000145:classification* / Q000235:genetics; D018272:Porins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012703:Serotyping
chemical_list: D018272:Porins; C057699:porin protein, Neisseria