Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Host organism: Homo sapiens
Associated disease: nosocomial infections [ICD11:
XB25 
];
infection due to Klebsiella pneumoniae [ICD11:
XN741 
]
The structure was elucidated in this paperNCBI PubMed ID: 36191686Publication DOI: 10.1016/j.virusres.2022.198951Journal NLM ID: 8410979Publisher: Virus Res
Correspondence: N.V. Volozhantsev <nikvol

obolensk.org>
Institutions: State Research Center for Applied Microbiology and Biotechnology, Obolensk, Russia
Bacteriophages and phage polysaccharide-degrading enzymes (depolymerases) are garnering attention as possible alternatives to antibiotics. Here, we describe the antimicrobial properties of bacteriophage KpV74 and phage depolymerase Dep_kpv74 specific to the hypervirulent Klebsiella pneumoniae of the K2 capsular type. The depolymerase Dep_kpv74 was identified as a specific glucosidase that cleaved the K2 type capsular polysaccharides of the K. pneumoniae by a hydrolytic mechanism. This depolymerase was effective against thigh soft tissue K. pneumoniae infection in mice without inducing adverse behavioral effects or toxicity. The depolymerase efficiency was similar to or greater than the bacteriophage efficiency. The phage KpV74 had a therapeutic effect only for treating the infection caused by the phage-propagating K. pneumoniae strain and was completely inactive against the infection caused by the K. pneumoniae strain that did not support phage multiplication. The depolymerase was effective in both cases. A mutant resistant to phage and depolymerase was isolated during the treatment of mice with bacteriophage. A confirmed one-base deletion in the flippase-coding wzx gene of this mutant is assumed to affect the polysaccharide capsule, abolishing the KpV74 phage adsorption and reducing the K. pneumoniae virulence.
Klebsiella pneumoniae, bacteriophage, polysaccharide depolymerase, glucosidase, phage resistance, phage therapy
Structure type: polymer chemical repeating unit
Location inside paper: Fig. 3, K2 CPS
Trivial name: K-antigen
Compound class: CPS, O-polysaccharide
Contained glycoepitopes: IEDB_115136,IEDB_1334432,IEDB_1334433,IEDB_1334434,IEDB_1334435,IEDB_137485,IEDB_140630,IEDB_142488,IEDB_144983,IEDB_144998,IEDB_146664,IEDB_152206,IEDB_153755,IEDB_983930,IEDB_983931,SB_192,SB_44,SB_72
Methods: 13C NMR, 1H NMR, NMR-2D, GPC, cloning, HR-ESI-MS, sequencing, bacteriophage assays, phage depolymerization, phage adsorption inhibition test, In vivo K. pneumoniae infection model
Comments, role: published polymerization frame was shifted for conformity with other records
Related record ID(s): 8867, 8868
NCBI Taxonomy refs (TaxIDs): 573Reference(s) to other database(s): GTC:G73682RA, GlycomeDB:
2875
Show glycosyltransferases
NMR conditions: in D2O at 313 K
[as TSV]
13C NMR data:
Linkage Residue C1 C2 C3 C4 C5 C6
4,4 bDGlcp 103.7 73.5 84.0 71.6-71.7 77.6 62.2
4,3 aDGlcpA 102.8 72.8 74.7 72.8 73.0 ?
4 bDManp 101.1 72.2 82.3 73.5 76.7 61.2
aDGlcp 100.4 72.7 72.8 79.9 71.6-71.7 61.2
1H NMR data:
Linkage Residue H1 H2 H3 H4 H5 H6
4,4 bDGlcp 4.52 3.37 3.62 3.52 3.52 3.72-3.96
4,3 aDGlcpA 5.18 3.54 3.79 3.55 4.25 -
4 bDManp 4.77 4.20 3.86 4.06 3.57 3.83-4.00
aDGlcp 5.28 3.59 3.88 3.68 4.05 3.74-3.78
1H/13C HSQC data:
Linkage Residue C1/H1 C2/H2 C3/H3 C4/H4 C5/H5 C6/H6
4,4 bDGlcp 103.7/4.52 73.5/3.37 84.0/3.62 71.6-71.7/3.52 77.6/3.52 62.2/3.72-3.96
4,3 aDGlcpA 102.8/5.18 72.8/3.54 74.7/3.79 72.8/3.55 73.0/4.25
4 bDManp 101.1/4.77 72.2/4.20 82.3/3.86 73.5/4.06 76.7/3.57 61.2/3.83-4.00
aDGlcp 100.4/5.28 72.7/3.59 72.8/3.88 79.9/3.68 71.6-71.7/4.05 61.2/3.74-3.78
1H NMR data:
| Linkage | Residue | H1 | H2 | H3 | H4 | H5 | H6 |
| 4,4 | bDGlcp | 4.52 | 3.37 | 3.62 | 3.52 | 3.52 | 3.72 3.96 |
| 4,3 | aDGlcpA | 5.18 | 3.54 | 3.79 | 3.55 | 4.25 |
|
| 4 | bDManp | 4.77 | 4.20 | 3.86 | 4.06 | 3.57 | 3.83 4.00 |
| | aDGlcp | 5.28 | 3.59 | 3.88 | 3.68 | 4.05 | 3.74 3.78 |
|
13C NMR data:
| Linkage | Residue | C1 | C2 | C3 | C4 | C5 | C6 |
| 4,4 | bDGlcp | 103.7 | 73.5 | 84.0 | 71.6 71.7 | 77.6 | 62.2 |
| 4,3 | aDGlcpA | 102.8 | 72.8 | 74.7 | 72.8 | 73.0 | ? |
| 4 | bDManp | 101.1 | 72.2 | 82.3 | 73.5 | 76.7 | 61.2 |
| | aDGlcp | 100.4 | 72.7 | 72.8 | 79.9 | 71.6 71.7 | 61.2 |
|
 The spectrum also has 1 signal at unknown position (not plotted). |
There is only one chemically distinct structure: