The Small Protein RmpD Drives Hypermucoviscosity in Klebsiella pneumoniae
Kimberly A. Walker, Logan P. Treat, Victoria E. Sepúlveda, Virginia L. Miller
Abstract
Capsule is a critical virulence factor in Klebsiella pneumoniae , in both antibiotic-resistant classical strains and hypervirulent strains. Hypervirulent strains usually have a hypermucoviscosity (HMV) phenotype that contributes to their heightened virulence capacity, but the production of HMV is not understood. The transcriptional regulator RmpA is required for HMV and also activates capsule gene expression, leading to the assumption that HMV is caused by hyperproduction of capsule. We have identified a new gene ( rmpD ) required for HMV but not for capsule production. This distinction between HMV and capsule production will promote a better understanding of the mechanisms of hypervirulence, which is in great need given the alarming increase in clinical isolates with both drug resistance and hypervirulence traits.