Clonal expansion of sequence type (ST-)5 and emergence of ST-7 in serogroup A meningococci, Africa

Emerg Infect Dis. 2001 Sep-Oct;7(5):849-54. doi: 10.3201/eid0705.010513.

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.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Africa / epidemiology
  • Bacterial Typing Techniques / methods*
  • DNA, Bacterial / analysis
  • Disease Outbreaks*
  • Humans
  • Meningitis, Meningococcal / epidemiology*
  • Meningitis, Meningococcal / microbiology
  • Neisseria meningitidis / classification*
  • Neisseria meningitidis / genetics*
  • Sequence Analysis, DNA / methods*
  • Serotyping

Substances

  • DNA, Bacterial