Tracking key virulence loci encoding aerobactin and salmochelin siderophore synthesis in Klebsiella pneumoniae

Klebsiella pneumoniae is a recognised agent of multidrug-resistant (MDR) healthcare-associated infections; however, individual strains vary in their virulence potential due to the presence of mobile accessory genes. In particular, gene clusters encoding the biosynthesis of siderophores aerobactin (iuc) and salmochelin (iro) are associated with invasive disease and are common amongst hypervirulent K. pneumoniae clones that cause severe community-associated infections such as liver abscess and pneumonia. Concerningly, iuc has also been reported in MDR strains in the hospital setting, where it was associated with increased mortality, highlighting the need to understand, detect and track the mobility of these virulence loci in the K. pneumoniae population. Here, we examined the genetic diversity, distribution and mobilisation of iuc and iro loci amongst 2503 K. pneumoniae genomes using comparative genomics approaches and developed tools for tracking them via genomic surveillance. Iro and iuc were detected at low prevalence (