Molecular surveillance of Neisseria meningitidis capsular switching in Portugal, 2002-2006.
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.
Simões
M J
MJ
Department of Infectious Diseases, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisboa, Portugal. m.joao.simoes@insa.min-saude.pt
Cunha
M
M
Almeida
F
F
Furtado
C
C
Brum
L
L
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
D004269:DNA, Bacterial