Journal Article
- Characterization of Newly Isolated Bacteriophages Targeting Carbapenem-Resistant Klebsiella pneumoniae
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Bokyung Kim, Shukho Kim, Yoon-Jung Choi, Minsang Shin, Jungmin Kim
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J. Microbiol. 2024;62(12):1133-1153. Published online December 10, 2024
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DOI: https://doi.org/10.1007/s12275-024-00180-7
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Abstract
- Klebsiella pneumoniae, a Gram-negative opportunistic pathogen, is increasingly resistant to carbapenems in clinical settings. This growing problem necessitates the development of alternative antibiotics, with phage therapy being one promising option. In this study, we investigated novel phages targeting carbapenem-resistant Klebsiella pneumoniae (CRKP) and evaluated their lytic capacity against clinical isolates of CRKP. First, 23 CRKP clinical isolates were characterized using Multi-Locus Sequence Typing (MLST), carbapenemase test, string test, and capsule typing. MLST classified the 23 K. pneumoniae isolates into 10 sequence types (STs), with the capsule types divided into nine known and one unknown type. From sewage samples collected from a tertiary hospital, 38 phages were isolated. Phenotypic and genotypic characterization of these phages was performed using Random Amplification of Polymorphic DNA-PCR (RAPD-PCR), transmission electron microscopy (TEM), and whole genome sequencing (WGS) analysis. Host spectrum analysis revealed that each phage selectively lysed strains sharing the same STs as their hosts, indicating ST-specific activity.
These phages were subtyped based on their host spectrum and RAPD-PCR, identifying nine and five groups, respectively. Fourteen phages were selected for further analysis using TEM and WGS, revealing 13 Myoviruses and one Podovirus. Genomic analysis grouped the phages into three clusters: one closely related to Alcyoneusvirus, one to Autographiviridae, and others to Straboviridae. Our results showed that the host spectrum of K. pneumoniae-specific phages corresponds to the STs of the host strain. These 14 novel phages also hold promise as valuable resources for phage therapy against CRKP.
Research Support, Non-U.S. Gov't
- Antibacterial Efficacy of Lytic Pseudomonas Bacteriophage in Normal and Neutropenic Mice Models
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Birendra R. Tiwari , Shukho Kim , Marzia Rahman , Jungmin Kim
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J. Microbiol. 2011;49(6):994-999. Published online December 28, 2011
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DOI: https://doi.org/10.1007/s12275-011-1512-4
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Abstract
- Recently, lytic bacteriophages (phages) have been focused on treating bacterial infectious diseases. We investigated the protective efficacy of a novel Pseudomonas aeruginosa phage, PA1Ø, in normal and neutropenic mice. A lethal dose of P. aeruginosa PAO1 was administered via the intraperitoneal route and a single
dose of PA1Ø with different multiplicities of infection (MOI) was treated into infected mice. Immunocompetent mice infected with P. aeruginosa PAO1 were successfully protected by PA1Ø of 1 MOI, 10 MOI or 100 MOI with 80% to 100% survival rate. No viable bacteria were found in organ samples after 48 h of the phage treatment. Phage clearing patterns were different in the presence or absence of host bacteria but PA1Ø disappeared from all organs after 72 h except spleen in the presence of host bacteria. On the contrary, PA1Ø treatment could not protect neutropenic mice infected with P. aeruginosa PAO1 even though could extend their lives for a short time. In in vitro phage-neutrophil bactericidal test, a stronger bactericidal effect was observed in phage-neutrophil co-treatment than in phage single treatment without neutrophils, suggesting phage-neutrophil co-work is essential for the efficient killing of bacteria in the mouse model. In conclusion, PA1Ø can be possibly utilized in future phage therapy endeavors since it exhibited strong protective effects against virulent P. aeruginosa infection.