title: Clonal analysis of Neisseria meningitidis serogroup B strains in South Africa, 2002 to 2006: emergence of new clone ST-4240/6688.
abstract: From August 1999 through July 2002, hyperinvasive Neisseria meningitidis serogroup B (MenB) clonal complexes (CCs),  namely, ST-32/ET-5  (CC32) and ST-41/44/lineage 3 (CC41/44), were predominant in the Western Cape Province of South Africa. This study analyzed MenB invasive isolates from a national laboratory-based surveillance system that were collected from January 2002 through December 2006. Isolates were characterized by pulsed-field gel electrophoresis (PFGE) (n = 302), and multilocus sequence typing (MLST) and PorA and FetA typing were performed on randomly selected isolates (34/302, 11%). In total, 2,400 cases were reported, with the highest numbers from Gauteng Province (1,307/2,400, 54%) and Western Cape Province (393/2,400, 16%); 67% (1,617/2,400) had viable isolates and 19% (307/1,617) were identified as serogroup B. MenB incidence remained stable over time (P = 0.77) (average incidence, 0.13/100,000 population [range, 0.10 to 0.16/100,000 population]). PFGE (302/307, 98%) divided isolates (206/302, 68%) into 13 clusters and 96 outliers. The largest cluster, B1, accounted for 25% of isolates (76/302) over the study period; its prevalence decreased from 43% (20/47) in 2002 to 13% (8/62) in 2006 (P < 0.001), and it was common in the Western Cape (58/76, 76%). Clusters B2 and B3 accounted for 10% (31/302) and 6% (19/302), respectively, and showed no significant change over time and were predominant in Gauteng. Randomly selected isolates from clusters B1, B2, and B3 belonged to CC32, CC41/44, and the new CC4240/6688, respectively. Overall, 15 PorA and 12 FetA types were identified. MenB isolates were mostly diverse with no single dominant clone; however, CC32 and CC41/44 accounted for 35% and the new CC4240/6688 was the third most prevalent clone.
authors.affiliation: Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa.
authors.forename: Chivonne
authors.initials: C
authors.lastname: Moodley
authors.forename: Mignon
authors.initials: M
authors.lastname: du Plessis
authors.forename: Kedibone
authors.initials: K
authors.lastname: Ndlangisa
authors.forename: Linda
authors.initials: L
authors.lastname: de Gouveia
authors.forename: Keith P
authors.initials: KP
authors.lastname: Klugman
authors.forename: Anne
authors.initials: A
authors.lastname: von Gottberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D008875:Middle Aged; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D009345:Neisseria meningitidis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D012703:Serotyping; D013019:South Africa / Q000453:epidemiology; D055815:Young Adult