title: Characterization and genome analysis of novel bacteriophages infecting the opportunistic human pathogens Klebsiella oxytoca and K. pneumoniae.
abstract: Klebsiella is a genus of well-known opportunistic human pathogens that are associated with diabetes mellitus and chronic pulmonary obstruction; however, this pathogen is often resistant to multiple drugs. To control this pathogen, two Klebsiella-infecting phages, K. oxytoca phage PKO111 and K. pneumoniae phage PKP126, were isolated from a sewage sample. Analysis of their host range revealed that they infect K. pneumoniae and K. oxytoca, suggesting host specificity for members of the genus Klebsiella. Stability tests confirmed that the phages are stable under various temperature (4 to 60 °C) and pH (3 to 11) conditions. A challenge assay showed that PKO111 and PKP126 inhibit growth of their host strains by 2 log and 4 log, respectively. Complete genome sequencing of the phages revealed that their genome sizes are quite different (168,758 bp for PKO111 and 50,934 bp for PKP126). Their genome annotation results showed that they have no human virulence-related genes, an important safety consideration. In addition, no lysogen-formation gene cluster was detected in either phage genome, suggesting that they are both virulent phages in their bacterial hosts. Based on these results, PKO111 and PKP126 may be good candidates for development of biocontrol agents against members of the genus Klebsiella for therapeutic purposes. A comparative analysis of tail-associated gene clusters of PKO111 and PKP126 revealed relatively low homology, suggesting that they might differ in the way they recognize and infect their specific hosts.
authors.affiliation: Department of Food Science and Biotechnology, Institute of Life Sciences and Resources, Kyung Hee University, Yongin, 446-701, Korea.
authors.forename: Eun-Ah
authors.initials: EA
authors.lastname: Park
authors.affiliation: Department of Food Science and Biotechnology, Institute of Life Sciences and Resources, Kyung Hee University, Yongin, 446-701, Korea.
authors.forename: You-Tae
authors.initials: YT
authors.lastname: Kim
authors.affiliation: Department of Food Science and Biotechnology, Institute of Life Sciences and Resources, Kyung Hee University, Yongin, 446-701, Korea.
authors.forename: Jae-Hyun
authors.initials: JH
authors.lastname: Cho
authors.affiliation: Department of Food and Animal Biotechnology, Department of Agriculture Biotechnology, Research Institute of Agriculture and Life Sciences, and Center for Food and Bioconvergence, Seoul National University, Seoul, 151-921, Korea.
authors.forename: Sangryeol
authors.initials: S
authors.lastname: Ryu
authors.affiliation: Department of Food Science and Biotechnology, Institute of Life Sciences and Resources, Kyung Hee University, Yongin, 446-701, Korea. juhlee@khu.ac.kr.
authors.forename: Ju-Hoon
authors.initials: JH
authors.lastname: Lee
mesh_terms: D001435:Bacteriophages / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology*; D016679:Genome, Viral; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology*; D041121:Klebsiella oxytoca / Q000502:physiology / Q000821:virology*; D007711:Klebsiella pneumoniae / Q000502:physiology / Q000821:virology*; D016366:Open Reading Frames; D010802:Phylogeny; D014764:Viral Proteins / Q000235:genetics
chemical_list: D014764:Viral Proteins