AUTHOR=Hua Yunfen , Wu Yongqin , Guo Minjie , Ma Ruijing , Li Qingchuan , Hu Zheyuan , Chen Hongrui , Zhang Xingyu , Li Hui , Li Qingtian , He Ping 

TITLE=Characterization and Functional Studies of a Novel Depolymerase Against K19-Type Klebsiella pneumoniae

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.878800

DOI=10.3389/fmicb.2022.878800

ISSN=1664-302X

ABSTRACT=<p>Carbapenem-resistant <italic>Klebsiella pneumoniae</italic> (CRKP), a pathogen that causes severe nosocomial infections and yields a high mortality rate, poses a serious threat to global public health due to its high antimicrobial resistance. Bacteriophages encode polysaccharide-degrading enzymes referred to as depolymerases that cleave the capsular polysaccharide (CPS), one of the main virulence factors of <italic>K. pneumoniae</italic>. In this study, we identified and characterized a new capsule depolymerase K19-Dpo41 from <italic>K. pneumoniae</italic> bacteriophage SH-KP156570. Our characterization of K19-Dpo41 demonstrated that this depolymerase showed specific activities against K19-type <italic>K. pneumoniae</italic>. K19-Dpo41-mediated treatments promoted the sensitivity of a multidrug-resistant K19-type <italic>K. pneumoniae</italic> strain to the bactericidal effect of human serum and significantly increased the survival rate of <italic>Galleria mellonella</italic> infected with K19-type <italic>K. pneumoniae</italic>. Our results provided strong primary evidence that K19-Dpo41 was not only effective in capsular typing of K19-type <italic>K. pneumoniae</italic> but promising in terms of developing new alternative therapeutic strategies against K19-type CRKP infections in the future.</p>