Identification of three podoviruses infecting Klebsiella encoding capsule depolymerases that digest specific capsular types
Journal
Microbial Biotechnology
Journal Volume
12
Journal Issue
3
Pages
472-486
Date Issued
2019
Author(s)
Abstract
Klebsiella pneumoniae is an important human pathogen causing opportunistic nosocomial and community-acquired infections. A major public health concern regarding K. pneumoniae is the increasing incidence of multidrug-resistant strains. Here, we isolated three novel Klebsiella bacteriophages, KN1-1, KN3-1 and KN4-1, which infect KN1, KN3 and K56, and KN4 types respectively. We determined their genome sequences and conducted a comparative analysis that revealed a variable region containing capsule depolymerase-encoding genes. Recombinant depolymerase proteins were produced, and their enzymatic activity and specificity were evaluated. We identified four capsule depolymerases in these phages that could only digest the capsule types of their respective hosts. Our results demonstrate that the activities of these capsule depolymerases were correlated with the host range of each phage; thus, the capsule depolymerases are host specificity determinants. By generating a capsule mutant, we demonstrate that capsule was essential for phage adsorption and infection. Further, capsule depolymerases can enhance bacterial susceptibility to serum killing. The discovery of these phages and depolymerases lays the foundation for the typing of KN1, KN3, KN4 and K56 Klebsiella and could be useful alternative therapeutics for the treatment of K. pneumoniae infections.
SDGs
Other Subjects
bacterial enzyme; capsular-polysaccharide galactohydrolase; glycosidase; viral protein; Article; bacterial capsule; bacterial genome; bacterial strain; bacteriophage; bacterium isolation; comparative study; controlled study; enzyme activity; enzyme specificity; gene sequence; genetic code; nonhuman; Podoviridae; virus identification; bacterial capsule; biology; classification; DNA sequence; enzymology; genetics; genomics; host range; isolation and purification; Klebsiella; metabolism; Podoviridae; sewage; virology; virus attachment; virus entry; virus genome; Bacterial Capsules; Bacteriophages; Computational Biology; Genome, Viral; Genomics; Glycoside Hydrolases; Host Specificity; Klebsiella; Podoviridae; Sequence Analysis, DNA; Sewage; Substrate Specificity; Viral Proteins; Virus Attachment; Virus Internalization
Publisher
John Wiley and Sons Ltd
Type
journal article