Publications by authors named "Michiyo Shinohara"

Japan has reported 26 cases of coronavirus disease 2019 (COVID-19) linked to cruise tours on the River Nile in Egypt between March 5 and 15, 2020. Here, we characterized the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome of isolates from 10 travelers who returned from Egypt and from patients possibly associated with these travelers. We performed haplotype network analysis of SARS-CoV-2 isolates using genome-wide single-nucleotide variations.

View Article and Find Full Text PDF

The RNA-dependent RNA polymerase () and capsid () genes of 51 GII.2 human norovirus (HuNoV) strains collected during the period of 2004-2015 in Japan were analyzed. Full-length analyses of the genes were performed using next-generation sequencing.

View Article and Find Full Text PDF

We studied the molecular evolution of the capsid gene in all genotypes (genotypes 1-9) of human norovirus (NoV) genogroup I. The evolutionary time scale and rate were estimated by the Bayesian Markov chain Monte Carlo (MCMC) method. We also performed selective pressure analysis and B-cell linear epitope prediction in the deduced NoV GI capsid protein.

View Article and Find Full Text PDF

In this study, the amorphous calcium phosphate (ACP) method developed previously for calicivirus concentration from water was applied for norovirus detection from food. The viral recovery from cabbage, lettuce, or ham (10g of each) was firstly examined in seeding experiments with feline caliciviruses (FCVs). The viruses were concentrated by viral adsorption to ACP particles (0.

View Article and Find Full Text PDF

A novel concentration method using minute particles of amorphous calcium phosphate (ACP) was developed for the detection of caliciviruses including norovirus and sapovirus, agents of human gastroenteritis, from water. In seeding experiments with feline calicivirus (FCV), ACP particles were able to adsorb efficiently the viruses in water, and the FCV-concentrated solution was obtained by dissolution of the virus-adsorbing ACP particles with citric acid after centrifugation. By quantitative real-time RT-PCR, the recovery efficiencies from 300 ml ultrapure water seeded with 10³, 10⁴ and >10⁵ copies of FCV were 48, 68 and >100 %, respectively.

View Article and Find Full Text PDF

Enterovirus 71 (EV71) is one of the causative agents of hand, foot, and mouth disease (HFMD) and is known to cause encephalitis, but several reports have identified EV71 in cerebrospinal fluid (CSF). We detected EV71 in CSF from a 20-month-old infant. The patient was diagnosed with brainstem encephalitis associated with HFMD.

View Article and Find Full Text PDF

The aim of this study was to evaluate the applicability of diagnostic methods for dual-infected cases of human adenoviruses (AdVs) and coxsackieviruses type B (CBs). For this purpose, 100 nasopharyngeal samples from patients with acute exudative tonsillitis and clinically suspected AdV infection were analyzed. Using PCR and real-time PCR techniques for AdVs and CBs, we found 86 AdVs-only positive samples; we also found five dual-infected samples containing 5.

View Article and Find Full Text PDF

Human norovirus (NoV) strains cause a considerable number of outbreaks of gastroenteritis worldwide. Based on their capsid gene (VP1) sequence, human NoV strains can be grouped into two genogroups (GI and GII) and at least 14 GI and 17 GII genotypes (GI/1-14 and GII/1-17). Human NoV strains cannot be propagated in cell-culture systems, but expression of recombinant VP1 in insect cells results in the formation of virus-like particles (VLPs).

View Article and Find Full Text PDF

A rapid, sensitive, and specific assay to detect mumps virus RNA directly from clinical specimens using a real-time PCR assay was developed. The assay was capable of detecting five copies of standard plasmid containing cDNA from the mumps virus F gene. No cross-reactions were observed with other members of Paramyxoviridae, or with viruses or bacteria known to be meningitis pathogens.

View Article and Find Full Text PDF

Norovirus (NV) (formerly called Norwalk-like virus) is the most common cause of acute nonbacterial gastroenteritis in humans. Recently, we reported an NV genotyping scheme based on variability in the capsid N-terminal/shell (N/S) domain gene (Katayama et al., Virology 299:225-239, 2002).

View Article and Find Full Text PDF

Noroviruses (NVs) cause many cases of oyster- or clam-associated gastroenteritis in various countries. We collected 191 samples from Japanese oysters intended for raw consumption that had been harvested from the sea in two different areas between December 2001 and February 2002. To detect, quantitate, and phylogenetically analyze the NV genome in purified concentrates from the stomachs and digestive diverticula of these oysters, we amplified the NV capsid gene by reverse transcription-PCR.

View Article and Find Full Text PDF

We have developed an assay for the detection of Norwalk-like viruses (NLVs) based on reverse transcription-PCR (RT-PCR) that is highly sensitive to a broad range of NLVs. We isolated virus from 71 NLV-positive stool specimens from 37 outbreaks of nonbacterial acute gastroenteritis and sequenced the open reading frame 1 (ORF1)-ORF2 junction region, the most conserved region of the NLV genome. The data were subjected to multiple-sequence alignment analysis and similarity plot analysis.

View Article and Find Full Text PDF

Mumps virus (MuV) strains isolated in Saitama Prefecture, Japan, from 1997 to 2001, were examined by analyzing the SH and the F gene nucleotide sequences. The results of the SH gene analysis showed that only genotype G was found in 2001 as well as in 2000, and that genotype J, which we proposed as a new genotype in a previous study, was from a different lineage than the genotype J described by Tecle et al. (J.

View Article and Find Full Text PDF

"Norwalk-like viruses" (NLV), a member of the family Caliciviridae, are the major causative agents of acute gastroenteritis and are genetically divided into two groups, genogroup I (GI) and genogroup II (GII). We have determined the complete nucleotide sequences of 10 new NLV strains. Using this information together with eight known NLV sequences, the criteria to further classify genotypes of NLV were investigated.

View Article and Find Full Text PDF

Although various cell lines have been used for virus isolation, few study of virus isolation using MRC-5 cell, a human embryonic lung fibroblasts, have been reported in Japan. MRC-5 and other cell lines (Caco-2, Vero, RD-18s, LLC-MK2, HeLa, MDCK, FL, B95a and HMV-II), and suckling mouse were compared for isolation of viruses from clinical specimens. A total of 3,284 specimens, collected from clinics and hospitals in Saitama Prefecture between July 1997 and August 2001, were inoculated in these cells.

View Article and Find Full Text PDF

A rapid and efficient RT-PCR with fluorogenic probe(TaqMan-PCR) was developed for detection of Norwalk virus(NV) genomes in clinical specimens. We designed NV genogroup specific primers and fluorogenic probes in the junction of open reading frame (ORF)1 and ORF2. Eighty specimens from patients of gastroenteritis, in which NV-like particles were detected by electron microscopy, were examined by TaqMan-PCR and RT-PCR using primer sets previously reported; two sets in RdRp region of NV and one set in capsid region.

View Article and Find Full Text PDF

Norwalk-like viruses (NLV) are a major causative agent of nonbacterial gastroenteritis. There are still many NLV strains that are refractory to gene amplification by ordinary reverse transcription-polymerase chain reaction. This is due mainly to the genetic diversity among NLV, especially mismatches in the primer sequences, which limits this technique in clinical utility.

View Article and Find Full Text PDF