Publications by authors named "Saori Fukuda"

The live attenuated human rotavirus vaccine strain RIX4414 (Rotarix) is used worldwide to prevent severe rotavirus-induced diarrhea in infants. This strain was attenuated through the cell culture passaging of its predecessor, human strain 89-12, which resulted in multiple genomic mutations. However, the specific molecular reasons underlying its attenuation have remained elusive, primarily due to the absence of a suitable reverse genetics system enabling precise genetic manipulations.

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Key Clinical Message: Most drugs that cause adverse events are difficult to identify in critically ill patients undergoing polypharmacy. We share our experience in identifying the causative drug among four suspect drugs administered during emergency treatment.

Abstract: We present the case of a 93-year-old man who was admitted for the treatment of cerebrovascular events.

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Vaccine development for herpes simplex virus 2 (HSV-2) has been attempted, but no vaccines are yet available. A plasmid-based reverse genetics system for Rotavirus (RV), which can cause gastroenteritis, allows the generation of recombinant RV containing foreign genes. In this study, we sought to develop simian RV (SA11) as a vector to express HSV-2 glycoprotein D (gD2) and evaluated its immunogenicity in mice.

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Human rotavirus strains having the unconventional G3P[6] genotype have been sporadically detected in diarrheic patients in different parts of the world. However, the full genomes of only three human G3P[6] strains from Asian countries (China, Indonesia, and Vietnam) have been sequenced and characterized, and thus the exact origin and evolution of G3P[6] strains in Asia remain to be elucidated. Here, we sequenced and characterized the full genome of a G3P[6] strain (RVA/Human-wt/JPN/SO1199/2020/G3P[6]) found in a stool sample from a 3-month-old infant admitted with acute gastroenteritis in Japan.

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Objectives: Opportunities for health examinations are available for the early detection of illness. However, although the majority of people examined have findings discovered, particularly in occupational areas, many do not undergo re-examination (secondary examination). In this study, we used the Health Belief Model to investigate the factors that affect the decision to undergo secondary examination in occupational areas.

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Article Synopsis
  • The rotavirus (RVA) genome is made up of 11 double-stranded RNAs that encode 12 proteins, including six structural and six non-structural proteins, one of which is NSP6, a less-studied protein.
  • A previous study showed that a recombinant NSP6-deficient RVA grew in cell cultures but less abundantly compared to the original SA11-L2 strain.
  • In this study, researchers infected suckling mice with the NSP6-deficient virus and found that while they experienced diarrhoea, it was milder and shorter in duration than that caused by the original strain, suggesting NSP6 isn’t essential for RVA replication or pathogenicity.
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Article Synopsis
  • In 2018, unique G9P[8]-E2 human rotaviruses were found in children with diarrhea in various regions of Japan, including Tokyo.
  • Researchers analyzed the genomes of seven G9P[8]-E2 strains and found a distinct genetic structure, combining elements from different rotavirus strains.
  • The study indicates that these G9P[8]-E2 strains emerged from a reassortment of existing rotavirus strains and suggests a common origin due to their nearly identical genome sequences.
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  • Human G4P[6] rotavirus strains have been found in patients with diarrhea worldwide, but only one strain from Africa has been fully sequenced so far.
  • In this study, researchers characterized a unique G4P[6] strain from a Kenyan child, identifying its genome as having significant porcine origins due to interspecies transmission.
  • This is the first complete genome analysis of a human G4P[6] strain in East Africa, highlighting the genetic diversity and origins of these rotaviruses in the region.
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Introduction: The ability to predict which patients with a history of coronavirus disease (COVID-19) will exhibit a high antibody titer is necessary for more efficient screening of potential convalescent plasma donors. We aimed to identify factors associated with a high immunoglobulin G (IgG) titer in Japanese convalescent plasma donors after COVID-19.

Methods: This cross-sectional study included volunteers undergoing screening for convalescent plasma donation after COVID-19.

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Human rotaviruses (HuRVAs) are highly important causes of acute gastroenteritis in infants and young children worldwide. A lack of reliable and reproducible reverse genetics systems for HuRVAs has limited a proper understanding of HuRVA biology and also the rational design of live-attenuated vaccines. Since the development of the first reverse genetics system for RVAs (partially plasmid-based reverse genetics system) in 2006, there have been many efforts with the goal of generating infectious recombinant HuRVAs entirely from cloned cDNAs.

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Article Synopsis
  • The evolutionary patterns of G4P[6] rotavirus strains in humans are still unclear, particularly regarding their modes of transmission (animal to human vs. human to human).
  • Two specific G4P[6] strains were identified in Thailand from patients with severe diarrhea, showing unique genetic characteristics and similarities to porcine rotavirus strains.
  • Genetic and phylogenetic analyses reveal that these strains likely originated from independent transmissions between pigs and humans, which highlights the interactions and exchanges between rotavirus strains across species.
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Urinary antigen tests are a widely used rapid diagnostic method for Legionella pneumonia. However, conventional urinary antigen tests are unable to detect anything other than Legionella pneumophila serogroup 1. The Ribotest Legionella (Ribotest) can detect all serogroups by using antibodies recognizing L.

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With the recent establishment of robust reverse genetics systems for rotavirus, rotavirus is being developed as a vector to express foreign genes. However, insertion of larger sequences such as those encoding multiple foreign genes into the rotavirus genome has been challenging because the virus segments are small. In this paper, we attempted to insert multiple foreign genes into a single gene segment of rotavirus to determine whether it can efficiently express multiple exogenous genes from its genome.

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An unusual rotavirus strain with the G3P[10] genotype (RVA/Human-wt/THA/MS2015-1-0001/2015/G3P[10]) was identified in a stool sample from a hospitalized child aged 11 months with severe gastroenteritis in Thailand. In the current study, we sequenced and characterized the full genome of strain MS2015-1-0001. On full-genomic analysis, strain MS2015-1-0001 exhibited the following genotype configuration: G3-P[10]-I8-R3-C3-M3-A9-N3-T3-E3-H6, which is identical or closely related to those of bat and bat-like rotavirus strains (MYAS33-like).

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Reverse genetics technology allows one to engineer replication-competent viruses from cloned cDNAs at will. Since the establishment of the initial reverse genetics system for species A rotaviruses (RVAs) requiring a helper virus in 2006, attempts have been successfully made to improve this technology. Efficient generation of replication-competent RVAs is now possible from just 11 T7-driven plasmids encoding an RVA genome when the quantity ratio of the two rescue T7-driven plasmids for the NSP2 and NSP5 segments is increased by 3-fold in relation to that of the other nine plasmids (11 plasmid-only system).

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Reassortment is an important mechanism in the evolution of group A rotaviruses (RVAs), yielding viruses with novel genetic and phenotypic traits. The classical methods for generating RVA reassortants with the desired genetic combinations are laborious and time-consuming because of the screening and selection processes required to isolate a desired reassortant. Taking advantage of a recently developed RVA reverse genetics system based on just 11 cloned cDNAs encoding the RVA genome (11 plasmid-only system), we prepared a panel of simian SA11-L2 virus-based single-gene reassortants, each containing 1 segment derived from human KU virus of the G1P[8] genotype.

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Background: The worldwide spread of organisms with antimicrobial resistance is of concern, especially the trend of significantly increasing carbapenemase-producing Enterobacterales (CPE). In this study, we investigated the annual trend of intestinal CPE carriage rates in inpatients and healthy adults in a primary care hospital in Tenri, Japan.

Methods: We collected 551 samples of feces from inpatients in our institution and 936 samples from healthy people living in Tenri city from December 2012 to April 2015.

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Article Synopsis
  • Recent reports have surfaced regarding the emergence of unusual DS-1-like intergenogroup reassortant rotaviruses with G1/3/8 genotypes across various continents including Africa, Asia, Australia, Europe, and the Americas.
  • In Thailand, three novel strains (G9P[8] genotype) were discovered in stool samples from children with diarrhea, and their full genomes were analyzed.
  • Phylogenetic analysis revealed that these strains are unique multiple reassortants, indicating their genetic relationship with both human and co-circulating rotavirus strains, marking the first documentation of these specific reassortant strains.
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A reverse genetics technology is an incredibly useful technique both for a proper understanding of different aspects of virus biology and for the generation of complementary DNA (cDNA)-derived infectious viruses, which can act as safe and effective vaccines and viral vectors. Rotaviruses (RVAs), especially human RVAs (HuRVAs), had been very refractory to this technology until very recently. Here, we describe the historical background of the development of a long-awaited HuRVA reverse genetics system, culminating in the generation of replicative HuRVAs entirely from cloned cDNAs.

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Objective: We report a novel technique for acute occlusion of both intracranial and extracranial arteries (tandem lesions [TL]).

Case Presentation: A 67-year-old male was transferred to our hospital because of right hemiparesis and aphasia. MRA revealed occlusion of the left cervical internal carotid artery (ICA) and middle cerebral artery (MCA).

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Group A rotavirus (RVA) is a major cause of acute gastroenteritis in infants and young children worldwide. This study aims to clarify the distribution of G/P types and genetic characteristics of RVAs circulating in Thailand. Between January 2014 and September 2016, 1867 stool specimens were collected from children and adults with acute gastroenteritis in six provinces in Thailand.

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Obligate anaerobes exist as resident flora in various sites in humans, but they are also emphasized as endogenous causative microorganism of infections. We performed surveillance to understand the trend of drug susceptibility in obligate anaerobic bacteria in the Kinki area of Japan. In the experiment, we used 156 obligate anaerobe isolates collected from 13 institutions that participated in the Study of Bacterial Resistance Kinki Region of Japan.

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The emergence of unusual DS-1-like intergenogroup reassortant rotaviruses with a bovine-like G8 genotype (DS-1-like G8P[8] strains) has been reported in several Asian countries. During the rotavirus surveillance program in Japan in 2017, a DS-1-like G8P[8] strain (RVA/Human-wt/JPN/SO1162/2017/G8P[8]) was identified in 43 rotavirus-positive stool samples. Strain SO1162 was shown to have a unique genotype constellation, including genes from both genogroup 1 and 2: G8-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2.

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The generation of recombinant group A rotaviruses (RVAs) entirely from cloned cDNAs has been described only for a single animal RVA strain, simian SA11-L2. We recently developed an optimized RVA reverse genetics system based on only RVA cDNAs (11-plasmid system), in which the concentration of cDNA plasmids containing the NSP2 and NSP5 genes is 3- or 5-fold increased in relation to that of the other plasmids. Based on this approach, we generated a recombinant human RVA (HuRVA)-based monoreassortant virus containing the VP4 gene of the simian SA11-L2 virus using the 11-plasmid system.

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