Hisao Kurazono

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Primers to amplify the genes encoding the virulence factors of uropathogenic Escherichia coli, such as pilus associated with pyelonephritis (pap), haemolysin (hly), aerobactin (aer) and cytotoxic necrotizing factor 1 (cnf1) genes, were designed. The above primers along with previously reported primers for S fimbriae (sfa) and afimbrial adhesin I (afaI)(More)
Helicobacter pylori, a Gram-negative gastric bacterium, secretes VacA, a cytotoxin that causes vacuolar degeneration of susceptible cells. Velocity sedimentation analysis showed that treatment of VacA at alkaline pH led to disassembly of VacA oligomers, an observation reported previously for acid-treated VacA. Exposure of VacA to acid or alkali increased(More)
Helicobacter pylori VacA toxin contributes to the pathogenesis and severity of gastric injury. We found that incubation of AZ-521 cells with VacA resulted in phosphorylation of protein kinase B (Akt) and glycogen synthase kinase-3beta (GSK3beta) through a PI3K-dependent pathway. Following phosphorylation and inhibition of GSK3beta,beta-catenin was released(More)
Cholera toxin (CT), the most commonly used mucosal adjuvant in experimental animals, is unsuitable for humans because of potent diarrhea-inducing properties. We have constructed two CT-A subunit mutants, e.g., serine-->phenylalanine at position 61 (S61F), and glutamic acid-->lysine at 112 (E112K) by site-directed mutagenesis. Neither mutant CT (mCT), in(More)
The low virulence of quinolone- and fluoroquinolone-resistant Escherichia coli strains is known, although the reasons for this remain unclear. We surveyed the mutation patterns of quinolone resistance determining regions (QRDRs), phylogenetic distribution, prevalence of 18 urovirulence genes, and PAIusp subtypes in 89 fluoroquinolone-resistant E. coli(More)
PURPOSE Many virulence factors (VFs) have been reported in uropathogenic Escherichia coli. Recently we found a putative uropathogenic island including a gene encoding uropathogenic specific protein (USP). We have described the association between usp and other VFs reported previously. In the current study we examined epidemiological associations among 5(More)
The genetic and serological characteristics of Escherichia coli isolates from patients with uncomplicated cystitis (UC), complicated cystitis (CC), and complicated asymptomatic bacteriuria (CASB) were determined. Phylogenetic group B2 was predominant in all categories. The prevalences of 14 out of 18 virulence factor genes were similar among the three(More)
Cellular DNA extracted from Escherichia coli strain B2F1 (O91:H21) was found to contain two separate DNA sequences that hybridized with a Vero toxin 2 (VT2)-specific gene probe under stringent conditions. These two sequences were cloned and both were shown to encode a variant of Vero toxin 2 (VT2vh). The nucleotide sequences of the operons encoding VT2vh,(More)
PURPOSE The fecal-perineal-urethral hypothesis to explain the cause of urinary tract infections (UTI) by enteric bacteria has been supported by longitudinal studies using methods of serotyping and detecting urovirulence factors such as P fimbriae. However, genetic techniques to more accurately characterize Escherichia coli strains have not been exploited.(More)
  • Y Hamanaka, M Nakashima, +7 authors I Sekine
  • Gut
  • 2001
BACKGROUND Human beta-defensin 2 (hBD-2) plays a role in the innate defence system at mucosal surfaces. Colonisation of Helicobacter pylori in the stomach is an important pathological factor in gastrointestinal illnesses, including gastritis, peptic ulcer, and gastric adenocarcinoma. AIMS To evaluate the antibacterial role of hBD-2 against H pylori(More)