Enterohemorrhagic Escherichia coli O157 (O157) strains can be classified into clades (one of several phylogenetic groups) by single nucleotide polymorphisms (SNPs): these are clade 1, clade 2, clade 3, descendant and ancestral clades 4/5, clade 6, clade 7, clade 8, clade 9, and clade 12. Some recent studies showed that some O157 strains in clade 8 produced a larger amount of Shiga toxin (Stx) 2 than other strains. In this study, 1121 epidemiologically unlinked strains of O157 isolated in Chiba Prefecture, Japan were classified into clades during 1996-2014.
View Article and Find Full Text PDFObjective: In August 2012, an outbreak of enterohaemorrhagic Escherichia coli (EHEC) O157 infection was investigated by the City of Sapporo and Hokkaido Prefectural Government. The initial notification reported an illness affecting 94 residents of 10 private nursing homes distributed across multiple areas of Hokkaido, the northernmost island of Japan; at this time three cases were confirmed as EHEC O157 infection. The objectives of the investigation were to identify the source of infection and recommend control measures to prevent further illness.
View Article and Find Full Text PDFThe etiologic role of recently identified respiratory viruses for lower respiratory tract disease (LRTD) remains unclear in Japan. The purpose of this study was to investigate the prevalence of respiratory viruses in young children with LRTD. We prospectively examined 721 children who were under two years old and admitted to a single medical center in Japan with LRTD between April 2007 and March 2012.
View Article and Find Full Text PDFTo investigate systemic cytokine responses in human bocavirus (HBoV)-associated lower respiratory tract infection, serum cytokine profiles were analyzed in HBoV positive-children (n=14) using multiplex immunoassay. Concentrations of TNF-a, IL-2, IL-5 and IL-8 on admission were significantly different from those of respiratory syncytial virus-positive children (n=28). This unique cytokine response might partly explain some characteristic clinical features of HBoV-associated respiratory infection.
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