text: MLST has provided a more richly textured picture of bacteria within human populations and on strain variants that may be pathogenic to human, plants and animals. MLST technique was first used by Maiden et al. (1) to characterize Neisseria meningitidis using six loci. The application of MLST has clearly resolved the major meningococcal lineages known to be responsible for invasive disease around the world. To improve the level of discriminatory power between the major invasive lineages, seven loci are now being used and have been accepted by many laboratories as the method of choice for characterizing meningococcal isolates. It is a well known fact that recombinational exchanges commonly occur in N. meningitidis, leading to rapid diversification of meningococcal clones. MLST has successfully provided a reliable method for characterization of clones within other bacterial species in which the rates of clonal diversification are generally lower.