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ORIGINAL RESEARCH article

Front. Microbiol.
Sec. Phage Biology
Volume 15 - 2024 | doi: 10.3389/fmicb.2024.1472729
This article is part of the Research Topic Bacteriophages, Prophages, and Their Products: Regulating Bacterial Populations View all 5 articles

Isolation and preliminary characterization of a novel bacteriophage vB_KquU_jKuK6 that infects the multidrug-resistant pathogen Klebsiella quasipneumoniae

Provisionally accepted
Isaac P. Miller Isaac P. Miller Alma G. Laney Alma G. Laney Geoffrey Zahn Geoffrey Zahn Brock Sheehan Brock Sheehan Kiara Whitley Kiara Whitley Ruhul H. Kuddus Ruhul H. Kuddus *
  • Department of Biology, Utah Valley University, Orem, United States

The final, formatted version of the article will be published soon.

    Background: Klebsiella quasipneumoniae (previously known as K. pneumoniae K6) strains are among the multidrug-resistant hypervirulent bacterial pathogens. Phage therapy can help treat infections caused by such pathogens. Here we report some aspects of virology and therapeutic potentials of vB_KquU_jKuK6, a bacteriophage that infects Klebsiella quasipneumoniae. Methods: K. quasipneumoniae (ATCC 700603) was used to screen wastewater lytic phages. The isolate vB_KquU_jKuK6 that consistently created large clear plaques was characterized using standard virological and molecular methods.Results: vB_KquU_jKuK6 has a complex capsid with an icosahedral head (~60 nm) and a slender tail (~140 nm x 10 nm). The phage has a 51% AT-rich linear dsDNA genome (51,251 bp) containing 121 open reading frames. The genome contains genes encoding spanin, endolysin, and holin proteins necessary for lytic infection and a recombinase gene possibly involved in lysogenic infection. vB_KquU_jKuK6 is stable at -80 to +67 °C, pH 4-9, and brief exposure to one volume percent of chloroform. vB_KquU_jKuK6 has a narrow host range. Its lytic infection cycle involves a latency of 20 min and a burst size of 435 plaque-forming units. The phage can cause lysogenic infection, and the resulting lysogens are resistant to lytic infection by vB_KquU_jKuK6. vB_KquU_jKuK6 reduces the host cells' ability to form biofilm but fails to eliminate that ability. vB_KquU_jKuK6 demonstrates phage-antibiotic synergy and reduces the minimum inhibitory concentration of chloramphenicol and neomycin sulfate by about 8 folds.Conclusions: vB_KquU_jKuK6 cannot be directly used for phage therapy because it is a temperate bacteriophage. However, genetically modified strains of vB_KquU_jKuK6 alone or combined with antibiotics or other lytic Klebsiella phages can have therapeutic utilities in treating K. quasipneumoniae infections.

    Keywords: Klebsiella quasipneumoniae (K. pneumoniae K6), MDR/XDR bacterial pathogens, phage therapy, lytic/lysogenic infection cycle, Biofilm, phage-antibiotic synergy

    Received: 30 Jul 2024; Accepted: 23 Sep 2024.

    Copyright: © 2024 Miller, Laney, Zahn, Sheehan, Whitley and Kuddus. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Ruhul H. Kuddus, Department of Biology, Utah Valley University, Orem, United States

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