Genosubtyping by sequencing group A, B and C meningococci; a tool for epidemiological studies of epidemics, clusters and sporadic cases.
Genosubtyping, by sequencing variable regions (VRs) 1, 2 and 3 of the porA gene, was evaluated as a tool to detect clonality of isolates in meningococcal epidemics in Africa and clusters of disease in Sweden. All 63 examined meningococcal isolates were successfully genosubtyped. The isolates belonging to group A type 4 with genosubtype P1.20,9,35a showed little heterogeneity in African epidemics in 1988 and onwards. In Sweden, two meningococcal clones of group B type 15, with genosubtypes P1.7,16,35 and P1.7,16f,35, dominated during two clusters of meningococcal disease in 1995-96 and in sporadic cases thereafter. The characterisation of group C meningococci isolated during 1992 in Sweden indicated a cluster (type 2a with genosubtype P1.5a,10d,36b) connected with a discotheque visit. Two variants of VR2 (10p and 25b), not previously described, were found among the examined isolates. Nucleotide sequence analysis of VRs in the porA gene proved a valuable epidemiological tool since almost all isolates could be genosubtyped, in contrast to the phenotypic methods presently used.
Mölling
P
P
Department of Clinical Microbiology & Immunology, Orebro Medical Centre Hospital, Sweden. paula.molling@orebroll.se
Unemo
M
M
Bäckman
A
A
Olcén
P
P
D000349:Africa / Q000453:epidemiology; D015373:Bacterial Typing Techniques; D016021:Epidemiologic Studies; D005838:Genotype; D006801:Humans; D008585:Meningitis, Meningococcal / Q000453:epidemiology / Q000382:microbiology*; D009345:Neisseria meningitidis / Q000145:classification* / Q000235:genetics; D018272:Porins / Q000145:classification* / Q000235:genetics; D017422:Sequence Analysis, DNA
D018272:Porins; C057699:porin protein, Neisseria