Publications by authors named "Hiromi Obata"

Campylobacter jejuni is one of the major bacterial strains that cause diarrhea in humans. It has been associated with many cases of food poisoning in Japan caused by eating raw, undercooked, and/or improperly prepared chicken meat, liver, and grilled chicken (Yakitori). Campylobacter jejuni is also known to be a preceding infectious pathogen of Guillain-Barré syndrome (GBS), which has a considerably negative health impact on humans.

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Escherichia albertii is an emerging foodborne pathogen that causes diarrhea. E. albertii has been isolated from various foods, including pork and chicken meat, and environmental waters, such as river water.

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Aim: To investigate whether any reduction in all-cause mortality and cardiovascular disease morbidity was found over the decade in type 2 diabetes on real-world practice.

Methods: A prospective observational study was performed by following two independent cohorts recruited in 2004 (n = 3286, Cohort 1) and 2014 (n = 3919, Cohort 2). The primary outcome was a composite of onset of cardiovascular disease and death.

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Article Synopsis
  • * A study analyzed over 2,000 Salmonella isolates from humans and food from the 1990s to the 2010s, revealing shifts in the most common serovars causing illness.
  • * S. Schwarzengrund has emerged as a frequently isolated serovar, predominantly found in chicken meat and offal, suggesting a link between certain food sources and Salmonellosis in humans.
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Abstract: Escherichia albertii is an emerging foodborne pathogen. Owing to its distribution in river water, it is important to determine the presence of E. albertii in aquaculture-related foods.

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Article Synopsis
  • Campylobacter jejuni is a significant foodborne bacterium linked to gastrointestinal infections and is associated with Guillain-Barré syndrome (GBS) due to its similarity to human nerve components.
  • In a study analyzing 88 HS:19 isolates related to GBS, 87 were found to be of the same genetic type (ST22 / CC22) and a specific lipooligosaccharide classification (A1).
  • The research indicated that HS:19 showed high genetic similarity among isolates from different sources in Japan, suggesting a strong connection between the bacteria and GBS cases compared to other capsule types.
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We report a fatal case of hemolytic uremic syndrome with urinary tract infection in Japan caused by Shiga toxin-producing Escherichia coli. We genotypically identified the isolate as OX18:H2. Whole-genome sequencing revealed 3 potentially pathogenic lineages (OX18:H2, H19, and H34) that have been continuously isolated in Japan.

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The O-serogrouping of pathogenic is a standard method for subtyping strains for epidemiological studies and controls. O-serogroup diversification shows a strong association with the genetic diversity in some O-antigen biosynthesis gene clusters. Through genomic studies, in addition to the types of O-antigen biosynthesis gene clusters (Og-types) from conventional O-serogroup strains, a number of novel Og-types have been found in isolates.

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  • * In Japan, data from National Food Poisoning Statistics identified vegetables (50%) and private well water (22.2%) as the main sources of ETEC outbreaks, mirroring trends in developing regions.
  • * A study on the O148 serogroup revealed an effective detection method for ETEC in cut leeks using a two-step enrichment and real-time PCR targeting its enterotoxin gene, confirming ETEC’s persistence in Japan's environment.
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Asymptomatic carriers have a major influence on the spreading of norovirus infections. The objective of this study was to examine the characteristics of patients and asymptomatic carriers affected by norovirus-related community gastroenteritis outbreaks. No significant difference between the two groups was observed in terms of the number of norovirus-antibody complexes with respect to total numbers.

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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 epidemiological and bacteriological investigations on four foodborne outbreaks caused by a new type of enterotoxin-producing Clostridium perfringens are described. C. perfringens isolated from patients of these outbreaks did not produce any known enterotoxin and did not carry the C.

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Enterotoxigenic Escherichia coli (ETEC) caused 131 outbreaks in Tokyo, Japan, between 1966 and 2009. The major serogroups were O6, O27, O148, and O159. The incidence of serogroups O25 and O169 recently increased.

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Norovirus (NV) RNA has rarely been detected in foods despite the use of highly sensitive methods such as RT-PCR and real-time RT-PCR. In the modified method (A3T method) reported previously, a bacterial culture process was introduced into the standard protocol for NV detection to remove some inhibitor(s) present in food ingredients. To confirm the efficiency of the A3T method and to examine NV contamination in bivalve molluscs, we tried to detect NV RNA in bivalve molluscs on the market and in oyster samples associated with foodborne outbreaks by using the standard method and the A3T method.

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A box-lunch-associated food-borne outbreak occurred in Tokyo and Chiba Prefecture in June 2003 involved six types of enterotoxigenic Escherichia coli (ETEC). Fecal specimens from patients were screened for ETEC using colony-sweep polymerase chain reaction (PCR). Of the 84 fecal specimens examined, 56 (66.

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A specific serotype of Vibrio parahaemolyticus, O3:K6, has recently been linked to epidemics of gastroenteritis in Southeast Asia, Japan, and North America. These pandemic O3:K6 strains appear to have recently spread across continents from a single origin to reach global coverage, based on profiling of strains by several molecular typing methods. In this study, variable-number tandem repeats (VNTR)-based fingerprinting was applied to clinical and environmental V.

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Objectives: The pathophysiology of midventricular obstructive hypertrophic cardiomyopathy (MVO) is unknown. Patients with MVO and MVO-like cardiomyopathy were classified into three groups based on the cardioimaging morphological characteristics of the left ventricle to investigate their complications and treatment.

Methods: Four patients with MVO and one patient with disease-like MVO were admitted in our hospital from 1999 to 2005.

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The producibility of thermostable direct hemolysin (TDH) is the most important pathogenic factor in Vibrio parahaemolyticus. TDH (+) V. parahaemolyticus is usually isolated from patients having V.

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Severe pulmonary hypertension is one of the fetal complications in various connective tissue diseases. We report a case of severe pulmonary hypertension associated with primary Sjögren's syndrome. In a lung biopsy specimen, there were findings of intimal and medial hypertrophy with narrowing vessel lumina and plexiform lesions.

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To clarify the source and route of infection with Vero toxin-producing Escherichia coli (VTEC) in humans, we sampled gastrointestinal contents and isolated VTEC from wild birds captured to exterminate harmful birds between August 1997 and January 1998. Pigeons were caught in Sagamihara-shi and crows were caught in Sagamihara-shi, Kawasaki-shi, Yokohama-shi, and the Tokyo metropolitan area. The following results were obtained.

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