between strains in comparison with the population genetic framework. thus, for example in escherichia coli, identifying strains carrying toxin genes is more important than having a population genetics-based evaluation of prevalent strains. the advent of second-generation sequencing technologies has made it possible to obtain sequence information across the entire bacterial genome at relatively modest cost and effort, and mlst can now be assigned from whole-genome sequence information, rather than sequencing each locus separately as was the practice when mlst was first developed. whole-genome sequencing provides richer information for differentiating bacterial strains (mlst uses approximately 0.1% of the genomic sequence to assign type while disregarding the rest of the bacterial genome). for example, whole-genome sequencing of numerous isolates has revealed the single mlst lineage st258 of klebsiella pneumoniae comprises two distinct genetic clades, providing additional information about the evolution and spread of these multi-drug resistant organisms, and disproving the previous hypothesis of a single clonal origin for st258. databases mlst databases contain the reference allele sequences and sequence types for each organism, and also isolate epidemiological data. the websites contain interrogation and analysis software which allow users to query their allele sequences and sequence types. mlst is widely used as a tool for researchers and public healthcare workers. the majority of mlst databases are hosted at web server currently located in oxford university (pubmlst.org). the database hosted at the site hold the organism specific reference allele sequences and lists of sts for individual organisms. to assist the gathering and formatting of the utilized sequences a simple and free plug-in for firefox has been developed (link archived 2014-02-22 at the wayback machine).