title: Screening of KHP30-like prophages among Japanese Helicobacter pylori strains, and genetic analysis of a defective KHP30-like prophage sequence integrated in the genome of the H. pylori strain NY40.
abstract: We have recently reported the active Helicobacter pylori bacteriophages (phages), KHP30 and KHP40, the genomic DNAs of which exist as episomes in host bacterial strains isolated in Japan (i.e. pseudolysogeny). In this study, we examined the possibility of the lysogeny of active KHP30-like phages in Japanese H. pylori strains, because their genomes contain a putative integrase gene. Only the NY40 strain yielded partial detection of a KHP30-like prophage sequence in PCR among 174 Japanese H. pylori isolates, except for strains producing the above active phages. Next, according to the genomic analysis of the NY40 strain, the KHP30-like prophage sequence was found to be located from ca. 524 to 549 kb in the host chromosome. The attachment sites, attL and attR, in the NY40 genome showed almost the same genomic location and sequence as those detected in a French isolate B38, suggesting that an active parental KHP30-like phage had integrated into the ancestral NY40 genome in a site-specific manner. The prophage found in the NY40 genome was assumed to have been genetically modified, after site-specific integration. These, together with the data in the KHP30-like prophages of other H. pylori genomes, suggest that the lysogenic state of the KHP30-like phages is generally unstable.
authors.affiliation: Department of Veterinary Microbiology, School of Veterinary Medicine, Azabu University, Kanagawa 252-5201, Japan.
authors.forename: Jumpei
authors.initials: J
authors.lastname: Uchiyama
authors.affiliation: Department of Veterinary Microbiology, School of Veterinary Medicine, Azabu University, Kanagawa 252-5201, Japan.
authors.forename: Iyo
authors.initials: I
authors.lastname: Takemura-Uchiyama
authors.affiliation: Research Institute of Molecular Genetics, Kochi University, Kochi 783-8502, Japan.
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Kato
authors.affiliation: Department of Clinical Laboratory Medicine, Kochi Medical School, Kochi University, Kochi 783-8505, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Takeuchi
authors.affiliation: Department of Microbiology, Kitasato University School of Medicine, Kanagawa 252-0374, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Sakaguchi
authors.affiliation: Science Research Center, Kochi University, Kochi 783-8505, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Ujihara
authors.affiliation: Department of Microbiology and Infection, Kochi Medical School, Kochi University, Kochi 783-8505, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Daibata
authors.affiliation: Department of Veterinary Microbiology, School of Veterinary Medicine, Azabu University, Kanagawa 252-5201, Japan.
authors.forename: Hidekatsu
authors.initials: H
authors.lastname: Shimakura
authors.affiliation: Department of Veterinary Microbiology, School of Veterinary Medicine, Azabu University, Kanagawa 252-5201, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Okamoto
authors.affiliation: Department of Veterinary Microbiology, School of Veterinary Medicine, Azabu University, Kanagawa 252-5201, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sakaguchi
authors.affiliation: Department of Microbiology and Infection, Kochi Medical School, Kochi University, Kochi 783-8505, Japan matuzaki@kochi-u.ac.jp.
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Matsuzaki
mesh_terms: D002876:Chromosomes, Bacterial; D004279:DNA, Viral / Q000235:genetics; D016680:Genome, Bacterial; D016679:Genome, Viral; D023281:Genomics; D016480:Helicobacter pylori / Q000235:genetics* / Q000821:virology*; D019426:Integrases / Q000235:genetics; D007564:Japan; D008242:Lysogeny; D039002:Prophages / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA
chemical_list: D004279:DNA, Viral; D019426:Integrases
keywords: Helicobacter pylori; genome; prophage