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Phage and Klebsiella pneumoniae

Antibiotic resistance of Klebsiella pneumoniae has become an increasingly urgent medical safety issue worldwide. Bacteriophages have shown great potential in controlling Klebsiella pneumoniae populations. With comprehensive knowledge about phage and Klebsiella pneumoniae, Creative Biolabs offers support for the development of therapeutic phage against Klebsiella pneumoniae.

Klebsiella pneumoniae

Klebsiella pneumoniae is an encapsulated facultative anaerobic Gram-negative bacterium. As an opportunistic pathogen, it colonizes the skin, respiratory tract, gastrointestinal tract, and oral cavity asymptomatically, and causes pneumonia, bacteremia, endophthalmitis, meningitis, urinary tract infection, bacteremia, sepsis, wound infection, purulent liver abscess, and necrotizing fasciitis in immunocompromised individuals. Klebsiella pneumoniae infection can be metastable so serious complications often occur during infection.

Drug Resistance of Klebsiella pneumoniae

In general, highly virulent Klebsiella pneumoniae strains tend to remain pan-susceptible, however classical Klebsiella pneumoniae strains have increasingly acquired genes producing spectral β-lactamases and carbapenemases. The growing number of multidrug-resistant Klebsiella pneumoniae isolates makes it an important target for new therapeutic development. Klebsiella pneumoniae strains most commonly used for research and phage culture include the highly virulent K1, K2, K5, K20, K54, and K57 strains, and the well-characterized strain Kp37.

Heteroresistance detection of Klebsiella pneumoniae.Fig.1 Heteroresistance detection of Klebsiella pneumoniae. (Stojowska-Swedrzynska, 2022)

Toxicity and Anti-Immune Mechanisms

The pathogenicity of Klebsiella pneumoniae is mainly due to its virulence factors, which can bypass the innate immunity of the host and maintain the infection in mammals. Virulence factors commonly found in different strains include fimbrial adhesins, capsules, siderophores, biofilms, lipopolysaccharides, proteases, gelatinases, lipases, hemagglutination, hemolysis, and hypermucus formation. One of the most important virulence factors of Klebsiella pneumoniae is its polysaccharide capsule barrier, which encapsulates the bacterial body, allowing bacterial cells to spread within the host and overcome the protective mechanisms of the immune system.

Biofilm test of Klebsiella pneumoniae by microtiter plate method.Fig.2 Biofilm test of Klebsiella pneumoniae by microtiter plate method. (Hullur, 2022)

Phage for Klebsiella pneumoniae

Currently isolated and well-characterized Klebsiella pneumoniae phages include SopranoGao, MezzoGao, πVLC5, πVLC6, AltoGao, Sweeny, vB_KpnS_Carvaje, Marfa, KPP5665-2, etc. The vast majority of Klebsiella pneumoniae phages encode polysaccharide depolymerase, an enzyme presenting in the tail fiber or tail spine protein, which digests and cleaves the bacterial exopolysaccharide capsule by cleaving glycosidic bonds, making the bacteria vulnerable to subsequent bacteriophage infection or antibiotic treatment. Most phages encode a single depolymerase and thus only recognize and cleave one or a few capsule types, but some phages encode multiple depolymerases simultaneously.

The activity of two depolymerases and phages expressing them against Klebsiella pneumoniae.Fig.3 The activity of two depolymerases and phages expressing them against Klebsiella pneumoniae. (Volozhantsev, 2020)

As a potential antibacterial agent, bacteriophage and encoded depolymerase effectively and specifically destroy the cell wall structure of bacteria. To better develop and study antagonists of specific strains and perform comprehensive isolation, purification, and characterization of appropriate phages, Creative Biolabs provides novel phage-related services to help you extract, purify or develop suitable phage therapy for Klebsiella pneumoniae. In addition, we are also happy to improve our experimental techniques or develop new experimental protocols for your project. Please do not hesitate to contact us for more information.


  1. Stojowska-Swedrzynska, K.; et al. Antibiotic heteroresistance in Klebsiella pneumoniae. International Journal of Molecular Sciences. 2022, 23: 499.
  2. Hullur, M.S.; et al. Phenotypic characterization of virulence factors and antibiogram of Klebsiella pneumoniae isolates from various clinical samples - a cross-sectional study. Journal of Pure and Applied Microbiology. 2022, 10: 22207.
  3. Volozhantsev, P.K.; et al. Characterization and therapeutic potential of bacteriophage-encoded polysaccharide depolymerases with β Galactosidase activity against Klebsiella pneumoniae K57 capsular type. Antibiotics. 2020, 9: 732.
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