Distribution of Human Sapovirus Strain Genotypes over the Last Four Decades in Japan: a Global Perspective.

Sapovirus (SaV) infections are a public health problem because they cause acute gastroenteritis in humans of all ages, both sporadically and as outbreaks. However, only a limited amount of SaV sequence information, especially whole-genome sequences for all the SaV genotypes, is publicly available. Therefore, in this study, we determined the full/near-full-length genomic sequences of 138 SaVs from the 2001 to 2015 seasons in 13 prefectures across Japan.

A Longitudinal Study on Enteric Virus Contamination in Bivalves along the Coast of Ibaraki Prefecture, Japan.

Abstract: During the 2014 to 2018 seasons, we conducted a longitudinal study involving enteric virus surveillance in bivalves, including natural oysters and clams harvested in Ibaraki Prefecture, Japan. Some norovirus (NoV) contaminations were detected in natural oysters, whereas no enteric virus was found in clams. NoVs detected in oysters were of the genotypes GII.

Contrasting Results from Two Commercial Kits Testing for the Presence of Clostridium perfringens Enterotoxin in Feces from Norovirus-Infected Human Patients.

Background: Detection of Clostridium perfringens enterotoxin (CPE) is critical for disease surveillance; however, commercial testing kits produce contrasting results.

Methods: We examined the cause of the differing results from a reversed passive latex agglutination (RPLA) assay (PET-RPLA Toxin Detection Kit) and an enzyme-linked immunosorbent assay (C. perfringens Enterotoxin ELISA Kit) using 73 human norovirus-positive fecal samples from gastroenteritis patients across 22 episodes in Japan.

Molecular Evolution of the Protease Region in Norovirus Genogroup II.

Noroviruses are a major cause of viral epidemic gastroenteritis in humans worldwide. The protease (Pro) encoded in open reading frame 1 (ORF1) is an essential enzyme for proteolysis of the viral polyprotein. Although there are some reports regarding the evolutionary analysis of norovirus GII-encoding genes, there are few reports focused on the region.

High prevalence of hepatitis E virus infection among domestic pigs in Ibaraki Prefecture, Japan.

Background: Hepatitis E virus (HEV) is prevalent in pigs and may serve as a reservoir for human infection. However, data on HEV infections in pigs in Ibaraki Prefecture, Japan, are limited. Here, we clarified the process and course of HEV in naturally infected pigs.

Molecular Evolutionary Analyses of the RNA-Dependent RNA Polymerase Region in Norovirus Genogroup II.

Noroviruses are the leading cause of viral gastroenteritis in humans across the world. RNA-dependent RNA polymerase (RdRp) plays a critical role in the replication of the viral genome. Although there have been some reports on a limited number of genotypes with respect to the norovirus evolution of the region, no comprehensive molecular evolution examination of the norovirus GII genotype has yet been undertaken.

Genetic Analysis of Human Norovirus Strains in Japan in 2016-2017.

In the 2016/2017 winter season in Japan, HuNoV GII.P16-GII.2 strains (2016 strains) emerged and caused large outbreaks of acute gastroenteritis.

Phylogeny and Immunoreactivity of Norovirus GII.P16-GII.2, Japan, Winter 2016-17.

During the 2016-17 winter season in Japan, human norovirus GII.P16-GII.2 strains (2016 strains) caused large outbreaks of acute gastroenteritis.

Molecular Evolution of the Gene in Human Norovirus GII.4 Variants in 1974-2015.

Human norovirus (HuNoV) is a leading cause of viral gastroenteritis worldwide, of which GII.4 is the most predominant genotype. Unlike other genotypes, GII.

Characterisation of meticillin-resistant Staphylococcus aureus ST97 and ST5 isolated from pigs in Japan.

The objective of this study was to determine the frequency and clonal types of meticillin-resistant Staphylococcus aureus (MRSA) among slaughter pigs in a top pig-producing area in Japan. In total, 100 nasal swabs were collected from slaughterhouse pigs originating from 21 different farms. MRSA isolates were analysed by staphylococcal cassette chromosome mec (SCCmec) typing, spa typing and multilocus sequence typing (MLST) and were examined for susceptibility to nine antimicrobial agents (ampicillin, oxacillin, gentamicin, kanamycin, erythromycin, clindamycin, vancomycin, ciprofloxacin and tetracycline).

Molecular evolution of the capsid gene in human norovirus genogroup II.

Capsid protein of norovirus genogroup II (GII) plays crucial roles in host infection. Although studies on capsid gene evolution have been conducted for a few genotypes of norovirus, the molecular evolution of norovirus GII is not well understood. Here we report the molecular evolution of all GII genotypes, using various bioinformatics techniques.

The high prevalence of hepatitis E virus infection in wild boars in Ibaraki Prefecture, Japan.

Hepatitis E virus (HEV) is known as a causative agent of zoonosis and food poisoning. Pigs and some species of wild animals, including wild boar, are known to be a reservoir of HEV. In this study, we investigated the situation regarding HEV infection in wild boars in Ibaraki Prefecture, Japan.

Sensitive and specific PCR systems for detection of both Chinese and Japanese severe fever with thrombocytopenia syndrome virus strains and prediction of patient survival based on viral load.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with a high case fatality risk and is caused by the SFTS virus (SFTSV). A retrospective study conducted after the first identification of an SFTS patient in Japan revealed that SFTS is endemic to the region, and the virus exists indigenously in Japan. Since the nucleotide sequence of Japanese SFTSV strains contains considerable differences compared with that of Chinese strains, there is an urgent need to establish a sensitive and specific method capable of detecting the Chinese and Japanese strains of SFTSV.