Molecular epidemiology of Coxsackievirus A16 strains isolated from children in Yamagata, Japan between 1988 and 2011.

To clarify the longitudinal molecular epidemiology of coxsackievirus A16, phylogenetic analysis based on the VP1 region of 220 isolates in Yamagata, Japan was performed. The resultant phylogenetic tree indicates that the Yamagata isolates and reference strains can be readily genotyped into three genogroups, and 0, 12 and 208 isolates belonged to the first, second, and third genogroups, respectively. The first genogroup includes only the prototype strain, the second strains that had disappeared by the end of the 20th century and the third comprises those that have been circulating since then in local communities, such as Yamagata.

Seasonal patterns of respiratory syncytial virus, influenza A virus, human metapneumovirus, and parainfluenza virus type 3 infections on the basis of virus isolation data between 2004 and 2011 in Yamagata, Japan.

Most acute respiratory infections (ARIs) are thought to be associated with respiratory viruses that cause similar symptoms. Therefore, assessment of clinical and epidemiologic features of these viruses is important for diagnosing a viral infection. We collected 13,325 nasopharyngeal specimens from patients with ARIs and isolated the virus using a microplate method involving 7 cell lines between 2004 and 2011 in Yamagata, Japan.

Proposed vector candidate: Leptotrombidium palpale for Shimokoshi type Orientia tsutsugamushi.

To identify the vector species for Shimokoshi type Orientia tsutsugamushi, a survey of larval trombiculid mites was conducted in Yamagata Prefecture, Japan from April to May 2012. In all, 2889 larval trombiculid mites were obtained from 21 Apodemus speciosus rodent hosts, 2600 of which were morphologically classified into eight species in three genera. After screening of O.

Subcutaneous abscess formation in the upper extremity caused by toxigenic Corynebacterium ulcerans.

Corynebacterium ulcerans is attracting attention as an emerging zoonosis that causes lymphadenitis, dermatitis and respiratory infections. We report here what appears to be the first case of subcutaneous abscess formation in the upper extremity due to toxigenic C. ulcerans in Japan.

Community outbreak of macrolide-resistant Mycoplasma pneumoniae in Yamagata, Japan in 2009.

Background: We detected a community outbreak of macrolide-resistant Mycoplasma pneumoniae infection that occurred predominantly among students at 2 schools in Yamagata, Japan.

Methods: Throat swab specimens were collected from patients who were clinically suspected to have M. pneumoniae infection after testing negative for influenza virus by a nasopharyngeal swab rapid antigen test.

Epidemiology of parainfluenza virus types 1, 2 and 3 infections based on virus isolation between 2002 and 2011 in Yamagata, Japan.

To clarify the epidemiology of viral acute respiratory infections (ARIs), 305 human parainfluenza virus types 1 (HPIV1), 154 HPIV2 and 574 HPIV3 strains were isolated from 16,962 nasopharyngeal swabs obtained between 2002 and 2011 at pediatric clinics in Yamagata, Japan. The total isolation frequency for HPIV1-3 was 6.1%.

Molecular epidemiology of the attachment glycoprotein (G) gene in respiratory syncytial virus in children with acute respiratory infection in Japan in 2009/2010.

This study performed a detailed genetic analysis of the glycoprotein (G) gene of respiratory syncytial virus (RSV) detected in 50 Japanese children with acute respiratory infection (ARI) in the 2009/2010 season. A phylogenetic tree constructed by the neighbour-joining method showed that 34 and 16 of the RSV strains could be classified into subgroups A and B, respectively. Strains belonging to subgroups A and B were further subdivided into GA2 and BA, respectively.

Acute respiratory infections due to enterovirus 68 in Yamagata, Japan between 2005 and 2010.

To clarify the epidemiology of enterovirus 68 (EV68), which is one of the most rarely identified enteroviruses, virus isolation and molecular screening using RT-PCR was performed on 6307 respiratory specimens collected at pediatric clinics in Yamagata, Japan between 2005 and 2010. In the years 2005-2009, 10, 1, 2, 0, and 2 (40) EV68-positive cases, respectively, were identified by RT-PCR. In 2010, 40 cases were identified altogether: 2 by isolation only, 26 by RT-PCR only, and 12 by both isolation and RT-PCR.

[Sequence analysis subtyping of the 56-kDa protein-encoding gene of Karp-type Orientia tsutsugamushi isolated in scrub typhus cases].

To determine the Karp-type Orientia tsutsugamushi subtype in northern Japan, i.e., Yamagata, Niigata, and Akita Prefectures, we analyzed the partial nucleotide sequence of the 56-kDa protein-encoding gene of 30 isolates from scrub typhus cases.

Detailed genetic analysis of hemagglutinin-neuraminidase glycoprotein gene in human parainfluenza virus type 1 isolates from patients with acute respiratory infection between 2002 and 2009 in Yamagata prefecture, Japan.

Background: Human parainfluenza virus type 1 (HPIV1) causes various acute respiratory infections (ARI). Hemagglutinin-neuraminidase (HN) glycoprotein of HPIV1 is a major antigen. However, the molecular epidemiology and genetic characteristics of such ARI are not exactly known.

Molecular epidemiological study of human rhinovirus species A, B and C from patients with acute respiratory illnesses in Japan.

Recent studies suggest that human rhinovirus species A, B and C (HRV-ABCs) may be associated with both the common cold and severe acute respiratory illnesses (ARIs) such as bronchiolitis, wheezy bronchiolitis and pneumonia. However, the state and molecular epidemiology of these viruses in Japan is not fully understood. This study detected the genomes of HRV-ABCs from Japanese patients (92 cases, 0-36 years old, mean±sd 3.

Endemicity of human metapneumovirus subgenogroups A2 and B2 in Yamagata, Japan, between 2004 and 2009.

To clarify a longitudinal epidemiology,we isolated 280 hMPV strains from patients with acute respiratory infections in Yamagata, Japan, between 2004 and 2009.We observed that the high season for hMPV was from winter to spring (between January and May) and the low season was in the fall (around September and October). A further molecular analysis revealed that subgenogroup A2 (A2) strains were the most commonly isolated (151/280; 53.

Comparison of virus isolation using the Vero E6 cell line with real-time RT-PCR assay for the detection of human metapneumovirus.

Background: The use of cell culture for the diagnosis of human metapneumovirus (hMPV) infection is uncommon at present and molecular method such as reverse-transcription PCR (RT-PCR) has been widely and most commonly used as the preferred test. We aimed to compare the results of virus isolation using Vero E6 cells with real-time RT-PCR for the detection of hMPV, since such a comparison data is not available.

Methods: Between December 2007 and July 2008, we obtained 224 nasopharyngeal swab specimens from patients with acute respiratory infection and tested by the two methods.

Duration of norovirus excretion and the longitudinal course of viral load in norovirus-infected elderly patients.

To prevent dissemination of norovirus in semiclosed environments such as aged-care facilities, it is important to know the period of infectivity in norovirus-infected individuals. We recruited 13 elderly patients aged 60-98 years with norovirus gastroenteritis (11 residents in aged-care facilities and two healthy adults) for this study, and measured the viral loads for norovirus in a total of 63 follow-up faecal samples using a real-time quantitative polymerase chain reaction assay. The average period of norovirus excretion was 14.

Characterization of Legionella pneumophila isolates from patients in Japan according to serogroups, monoclonal antibody subgroups and sequence types.

We collected 86 unrelated clinical Legionella pneumophila strains that were isolated in Japan during the period 1980-2008. Most (80.2%) belonged to serogroup 1, followed by serogroups 5, 3 and 2.

Phylogenetic and cluster analysis of human rhinovirus species A (HRV-A) isolated from children with acute respiratory infections in Yamagata, Japan.

We performed phylogenetic and cluster analysis of human rhinovirus species A (HRV-A) isolated from 76 children with acute respiratory infection in Yamagata prefecture, Japan during the period 2003-2007. Phylogenetic trees based on the nucleotide and amino acid sequences of the VP4/VP2 coding region showed that the present strains could be classified into 11 and 8 clusters, respectively. The homology among the present strains ranged from 66.

[Occurrence of Tsutsugamushi disease infection by Orientia tsutsugamushi, Kawasaki serotype, in Yamagata Prefecture, Japan].

Of 95 Tsutsugamushi disease case occurring in Yamagata prefecture from 1999 to 2006, four-all women-involved the O. tsutsugamushi Kawasaki serotype. The three major symptoms were fever, exanthema, and eschar present from mid-October to early November.

[Determination of illudin S in Omphalotus guepiniformis and foods that caused food poisoning by liquid chromatography with tandem mass spectrometry].

A simple method was developed for determination of illudin S in fungi (Omphalotus guepiniformis: poisonous mushroom) and a food that caused food poisoning, using liquid chromatography tandem mass spectrometry (LC/MS/MS). Illudin S in fungi and the food that caused food poisoning was extracted with methanol and then cleaned up with an Oasis HLB cartridge. LC separation was performed with an octadecylated silica column (Inertsil ODS-3, 2.

Cross-antigenicity among EV71 strains from different genogroups isolated in Yamagata, Japan, between 1990 and 2007.

We isolated and identified six subgenogroups (B2, B4, B5, C1, C2, and C4) of enterovirus 71 (EV71) between 1990 and 2007 in Yamagata, Japan. We measured neutralizing antibody (NT Ab) titers against those subgenogroup strains and the BrCr reference strain for antigenic analysis. Serological analysis of 83 residents in Yamagata in 2004 showed that differences in the NT Ab titer of each individual against the different subgenogroups were mostly within 4-fold.

Development of an assay for the detection and quantification of the measles virus nucleoprotein (N) gene using real-time reverse transcriptase PCR.

We developed a new quantification method for the measles virus (MeV) nucleoprotein (N) gene using real-time reverse transcriptase PCR. This method allowed us to quantify 10(1)-10(7) copies per reaction (corresponding to 5x10(-1)-5x10(5) copies microl(-1)) of the MeV N gene. We also quantified the MeV N gene from the throat swabs of 22 patients with measles as well as the MeV genotypes A, D3, D5, D9 and H1 in viral suspensions derived from MeV-infected cells.