title: Molecular surveillance of Neisseria meningitidis capsular switching in Portugal, 2002-2006.
abstract: Neisseria meningitidis capsular switching has been reported in several countries. In order to establish the genetic relationship within group B and C strains expressing subtypes 2a or 2b, and to evaluate whether C to B capsular switching occurred in Portugal, 64 meningococci (56 serogroup C and 8 serogroup B) isolated from invasive meningococcal disease were typed using molecular methods. The studied phenotypes, 2b:P1.5,2 and 2a:P1.5-1,10-8, were the most frequent among serogroup C, but were uncommon among serogroup B strains. The multi-locus sequence typing (MLST) allelic profile and the pulsed-field gel electrophoresis (PFGE) fingerprints showed that seven serogroup B strains were genotypically identical to C strains, suggesting that capsular switching occurred. Active laboratory surveillance to find evidence of capsule switching is a now priority as MenC was introduced in the Portuguese vaccination schedule in January 2006.
authors.affiliation: Department of Infectious Diseases, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisboa, Portugal. m.joao.simoes@insa.min-saude.pt
authors.forename: M J
authors.initials: MJ
authors.lastname: Simões
authors.forename: M
authors.initials: M
authors.lastname: Cunha
authors.forename: F
authors.initials: F
authors.lastname: Almeida
authors.forename: C
authors.initials: C
authors.lastname: Furtado
authors.forename: L
authors.initials: L
authors.lastname: Brum
mesh_terms: D000940:Antigenic Variation; D016667:Bacterial Capsules / Q000235:genetics*; D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D009345:Neisseria meningitidis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D011174:Portugal / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D012703:Serotyping
chemical_list: D004269:DNA, Bacterial