Hypervirulent Klebsiella pneumoniae ST23: Hypervirulence Meets Antimicrobial Resistance

Hypervirulent Klebsiella pneumoniae can cause community-acquired invasive infections such as pyogenic liver abscess and endophthalmitis in healthy individuals compared to the classical K. pneumoniae, causing opportunistic healthcare-associated infections. Globally, K. pneumoniae clonal group 23, including sequence type (ST) 23, is the dominant clone causing hypervirulent invasive infections. K. pneumoniae ST23 clones harbor capsular serotype K1, together with hypervirulence-associated genes such as ybt, iuc, iro, rmpA, and rmpA2 encoded on hypervirulence plasmids, which can define the hypervirulence of K. pneumoniae ST23. Historically, antimicrobial resistance (AMR) has not been associated with K. pneumoniae ST23. However, the emergence of carbapenem-resistant K. pneumoniae ST23 has been reported from various countries, and regional clustering was reported, suggesting the spread of these strains globally. Genomic surveillance by whole-genome sequencing method should be implemented on a global scale to highlight the global and local trends in antimicrobial resistance and hypervirulence in K. pneumoniae ST23 clones.