What defines hypervirulent Klebsiella pneumoniae?

Klebsiella pneumoniae is a global pathogen with remarkable genetic, phenotypic and pathogenic diversity.1 Strains belonging to distinct groups of lineages cause ‘classical’ infections in hospitals, often with high rates of multidrug resistance, or drug-susceptible ‘hypervirulent’ infections in community settings, respectively; however there are increasing reports of convergence between these pathotypes and their genetic determinants, raising significant public health concerns.1–4 Sequence-type (ST) 23 strains are the dominant lineage causing hypervirulent infections, and associated with the K1 capsule type.