title: Clonal expansion of sequence type (ST-)5 and emergence of ST-7 in serogroup A meningococci, Africa.
abstract: One hundred four serogroup A meningococci in our collection, isolated in Africa from 1988 to 1999, were characterized by multilocus sequence typing (MLST). Our results and data from the Internet indicate that sequence type 5 (ST-5) strains were responsible for most of African outbreaks and sporadic cases during this period. In 1995, a new clone, characterized by ST-7 sequence, emerged and was responsible for severe outbreaks in Chad (1998) and Sudan (1999). MLST and epidemiologic data indicate that ST-5 and ST-7 represent two virulent clones. These two STs, which belong to subgroup III, differ only in the pgm locus: allele pgm3 is characteristic for ST-5 and allele pgm19 for ST-7. Subgroup III strains were responsible for two pandemics in the 1960s and 1980s. Our data show that the third subgroup III pandemic has now reached Africa.
authors.affiliation: Institut de Médecine Tropicale du Service de Santé des Armées, World Organization Collaborating Center, Marseille Armées, France. imtssa.meningo.free.fr
authors.forename: P
authors.initials: P
authors.lastname: Nicolas
authors.forename: L
authors.initials: L
authors.lastname: Décousset
authors.forename: V
authors.initials: V
authors.lastname: Riglet
authors.forename: P
authors.initials: P
authors.lastname: Castelli
authors.forename: R
authors.initials: R
authors.lastname: Stor
authors.forename: G
authors.initials: G
authors.lastname: Blanchet
mesh_terms: D000349:Africa / Q000453:epidemiology; D015373:Bacterial Typing Techniques / Q000379:methods*; D004269:DNA, Bacterial / Q000032:analysis; D004196:Disease Outbreaks; D006801:Humans; D008585:Meningitis, Meningococcal / Q000453:epidemiology* / Q000382:microbiology; D009345:Neisseria meningitidis / Q000145:classification* / Q000235:genetics*; D017422:Sequence Analysis, DNA / Q000379:methods*; D012703:Serotyping
chemical_list: D004269:DNA, Bacterial