Publications by authors named "Takehito Saitoh"

, a zoonotic enteropathogen, is responsible for outbreaks of disease in humans. Identifying strains of by phenotypic characterization tests is difficult because of its poorly defined properties. Screening its phenotypic characteristics is, nevertheless, a necessary prerequisite for further genetic analysis of its properties, and species-specific polymerase chain reaction (PCR) analysis can be used to type the pathogen.

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  • - Six cases of invasive meningococcal disease were reported among participants from Scotland and Sweden at the World Scout Jamboree in Japan, with all cases linked to the same rare strain.
  • - Health authorities in Scotland and Sweden took emergency actions including vaccinations and chemoprophylaxis for attendees, while Japan's Ministry of Health urged participants to seek medical help if symptoms appeared.
  • - No further cases were identified post-Jamboree, emphasizing the need for improved risk assessment, education, and communication among countries to prevent the spread of infections at large events.
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  • Japanese meningococcal disease has been tracked in Japan from 1999 to 2014, with a total of 178 cases of meningococcal meningitis reported and an additional 59 cases of invasive meningococcal disease (IMD) added after April 2013.
  • The majority of cases occurred in males, with a median age of 56 years, and only a small percentage (3%) of cases involved children under 5 years old; one-third were meningitis cases while the remainder were bacteremia.
  • Serogroup Y was the most prevalent (42%), and although reported cases increased following new reporting requirements, the overall incidence remains low at 0.028 per 100,000,
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The detailed epidemiology of meningococcal diseases in Japan has yet to be determined and, moreover, the healthy carriage rate is also unknown. In this study, to obtain insight into the carriage rate of Neisseria meningitidis in healthy individuals in Japan, we developed a new method to detect the N. meningitidis-specific ctrB gene, one of the genes encoding enzymes for capsule synthesis, by Loop-Mediated Isothermal Amplification (LAMP) and examined the meningococcal carriage rate by using self-collected oral throat wash specimens from 836 students at a university.

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Background: Enterohemorrhagic Escherichia coli (EHEC) is an important cause of gastroenteritis in Japan. Although non-O157 EHEC infections have been increasingly reported worldwide, their impact on children has not been well described.

Methods: We collected national surveillance data of EHEC infections reported between 2010 and 2013 in Japan and characterized outbreaks that occurred in childcare facilities.

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Background: Enterohemorrhagic Escherichia coli (EHEC) O157:H7 infection causes severe diseases such as bloody diarrhea and hemolytic uremic syndrome (HUS). Although EHEC O157:H7 strains have exhibited high genetic variability, their abilities to cause human diseases have not been fully examined.

Methods: Clade typing and stx subtyping of EHEC O157:H7 strains, which were isolated in Japan during 1999-2011 from 269 HUS patients and 387 asymptomatic carriers (ACs) and showed distinct pulsed-field gel electrophoresis patterns, were performed to determine relationships between specific lineages and clinical presentation.

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The locus of enterocyte effacement (LEE) pathogenicity island is required for the intimate adhesion of enterohemorrhagic Escherichia coli (EHEC) to the intestinal epithelial cells. GrlR and GrlA are LEE-encoded negative and positive regulators, respectively. The interaction of these two regulators is important for controlling the transcription of LEE genes through Ler, a LEE-encoded central activator for the LEE.

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The pathogenicity island termed locus of enterocyte effacement (LEE) encodes a type 3 protein secretion system, whose function is required for full virulence of enterohemorrhagic Escherichia coli (EHEC). GrlR and GrlA are LEE-encoded negative and positive regulators, respectively, for controlling transcription of the ler gene, which encodes a central activator of LEE gene expression. We previously reported that the GrlR-GrlA regulatory system controls not only the LEE genes but also flagellar gene expression in EHEC (S.

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Shiga toxin-producing Escherichia coli (STEC) are important enteropathogens causing severe diseases such as hemorrhagic colitis and hemolytic-uremic syndrome in humans. The majority of STEC strains of serogroups O157, O26, or O111 associated with severe cases of these diseases possess a pathogenicity island termed the locus of enterocyte effacement (LEE). LEE, which is responsible for the formation of attaching-and-effacing lesions on intestinal epithelial cells, is important for the full virulence of STEC.

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The gene function of the locus of enterocyte effacement (LEE) is essential for full virulence of enterohemorrhagic Escherichia coli (EHEC). Strict control of LEE gene expression is mediated by the coordinated activities of several regulatory elements. We previously reported that the ClpX/ClpP protease positively controls LEE expression by down-regulating intracellular levels of GrlR, a negative regulator of LEE gene expression.

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