A novel depolymerase specifically degrades the K62-type capsular polysaccharide of Klebsiella pneumoniae

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is emerging as an imminent threat to worldwide public health because of its high level of antimicrobial resistance, which can result in severe and challenging-to-treat infections. The capsular polysaccharide (CPS) of bacteria is well acknowledged as a crucial virulence factor that shields K. pneumoniae from the host’s innate immune system. Polysaccharide depolymerase, encoded by bacteriophages, can hydrolyze the CPS of K. pneumoniae and may be a promising approach for treating K. pneumoniae infections. In this study, we identified a novel K62-type capsule depolymerase (K62-Dpo30) from the K. pneumoniae phage SH-KP2492. We demonstrated that the K62-Dpo30 depolymerase could specifically degrade the CPS of K62-type K. pneumoniae strains and promote the susceptibility of K62-type K. pneumoniae strains to serum and neutrophil killing. Furthermore, our findings highlight the potential of the K62-Dpo30 depolymerase as a reliable K. pneumoniae capsular typing tool.