Related Experiment Video

Updated: Sep 12, 2025

Separating Bacteria by Capsule Amount Using a Discontinuous Density Gradient
05:52

Separating Bacteria by Capsule Amount Using a Discontinuous Density Gradient

Published on: January 7, 2019

14.3K

Isolation, characterization, therapeutic potential and depolymerase identification of a lytic bacteriophage Kpp-9

Menglu Wang1, Jiayi Liu2, Xin Jiao1

  • 1Department of Medical Laboratory, Shandong Second Medical University, Weifang, Shandong, 261053, PR China.

Microbial Pathogenesis
|August 7, 2025
PubMed

Insights

A novel lytic bacteriophage, Kpp-9, and its depolymerases show promise against multidrug-resistant Klebsiella pneumoniae. These agents effectively combat biofilms and enhance mouse survival, offering new therapeutic avenues.

Area of Science:

  • Microbiology
  • Bacteriophage Therapy
  • Antimicrobial Resistance

Background:

  • Klebsiella pneumoniae is a major multidrug-resistant pathogen.
  • Bacterial capsules and biofilms impede antibiotic treatment.
  • Bacteriophages and depolymerases are emerging as antibiotic alternatives.

Purpose of the Study:

  • To isolate and characterize a lytic bacteriophage against Klebsiella pneumoniae.
  • To evaluate the therapeutic potential of the phage and its depolymerases against K. pneumoniae infections.
  • To assess the efficacy of phage Kpp-9 and its depolymerases in combating biofilms and improving host survival.

Main Methods:

  • Isolation and characterization of lytic bacteriophage Kpp-9 from a K2 strain.
  • In vitro assessment of biofilm inhibition and eradication.
  • In vivo studies using a mouse model of K. pneumoniae pneumonia.
  • Genomic analysis of Kpp-9 for virulence and resistance genes.
  • Prediction and functional analysis of depolymerase enzymes.

Main Results:

  • Phage Kpp-9 inhibited and eradicated K. pneumoniae biofilms in vitro.
  • Kpp-9 treatment improved survival rates and alleviated pneumonia symptoms in infected mice.
  • Genomic analysis confirmed Kpp-9's safety profile, lacking virulence genes.
  • Two depolymerases, Kp9042 and Kp9050, digested the bacterial capsule, increasing susceptibility to serum killing.
  • Kpp-9 and depolymerases demonstrated high selectivity for K2 strains and good stability.

Conclusions:

  • Phage Kpp-9 is a potent agent against Klebsiella pneumoniae biofilms and infections.
  • Depolymerases Kp9042 and Kp9050 enhance the efficacy of phage therapy by degrading the capsule.
  • Kpp-9 and its depolymerases represent promising, specific therapeutic alternatives for capsule-type K2 K. pneumoniae infections.
Keywords:
BacteriophageDepolymeraseHypervirulent Klebsiella pneumoniaeK2 serotype

More Related Videos

Phage Phenomics: Physiological Approaches to Characterize Novel Viral Proteins09:40

Phage Phenomics: Physiological Approaches to Characterize Novel Viral Proteins

Published on: June 11, 2015

12.3K
Author Spotlight: Efficiently Eliminating Bacteriophages from Infected Salmonella Cultures Using Lipopolysaccharides07:19

Author Spotlight: Efficiently Eliminating Bacteriophages from Infected Salmonella Cultures Using Lipopolysaccharides

Published on: June 28, 2024

1.1K

Related Concept Videos

Lytic Cycle of Bacteriophages01:30

Lytic Cycle of Bacteriophages

Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the...
72.0K
Viral Replication: Lytic Cycle01:20

Viral Replication: Lytic Cycle

Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized lytic replication cycle in Escherichia coli (E. coli). This process ensures the rapid proliferation of the virus while ultimately leading to the destruction of the bacterial host.Attachment and DNA InjectionThe infection process begins with the recognition and binding of the T4 phage to the E. coli cell surface. Tail fibers of the phage...
256
Lysogenic Cycle of Bacteriophages00:43

Lysogenic Cycle of Bacteriophages

In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
63.2K
Viral Replication: Lysogenic Cycle01:16

Viral Replication: Lysogenic Cycle

The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. This process is primarily observed in temperate phages, such as bacteriophage lambda (λ), which infects Escherichia coli. The cycle allows the viral genome to persist across bacterial generations while keeping host cells viable.Integration of the Viral GenomeUpon infection, bacteriophage lambda attaches to the bacterial surface and injects...
243
DNA Bacteriophages01:26

DNA Bacteriophages

Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
149