Molecular surveillance of Neisseria meningitidis capsular switching in Portugal, 2002–2006

• Published in: Epidemiology and infection Vol. 137; no. 2; pp. 161 - 165
• Main Authors: SIMÕES, M. J., CUNHA, M., ALMEIDA, F., FURTADO, C., BRUM, L.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.02.2009
• Subjects: Antigenic Variation; Bacterial Capsules - genetics; Bacterial Infections; Bacterial Typing Techniques; Bacteriology; Biological and medical sciences; Capsular switching; Capsules; Cluster Analysis; DNA Fingerprinting; DNA, Bacterial - genetics; Electrophoresis; Electrophoresis, Gel, Pulsed-Field; Epidemiology; Fundamental and applied biological sciences. Psychology; Gels; Genotype; Humans; Infectious diseases; Meningitis; Meningococcal Infections - epidemiology; Meningococcal Infections - microbiology; Microbiology; Miscellaneous; Neisseria meningitidis; Neisseria meningitidis - classification; Neisseria meningitidis - genetics; Neisseria meningitidis - isolation & purification; Notifiable diseases; Phenotypes; Portugal - epidemiology; Sequence Analysis, DNA; Serotyping; Surveillance; Vaccination; Portugal; Europe; Neisseria meningitidis; Capsular switching; Microorganism capsule; Human; Microbiology; Neisseriaceae; Bacteria; Micrococcales; Epidemiology
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268808001106

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.