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Osamu Nishio

Publications and source records attributed to Osamu Nishio.

At least 19 recordsLinked to original sources
PubMed2007

Isolation and identification of adenovirus from conjunctival scrapings over a two-year period (between 2001 and 2003) in Yokohama, Japan.

Over a 2-year period between 2001 and 2003, a total of 115 conjunctival scrapings were collected from patients with keratoconjuctivitis from several hospitals in Yokohama, Japan. Out of 115, 94 (82.4%) cases of adenoviruses were detected by polymerase chain reaction (PCR); 60 (52.1%) by cell culture isolation; and 16 (14.0%) by enzyme-linked immunosorbent assay (ELISA). The serotypes were determined by PCR- restriction fragment length polymorphism analysis (PCR-RFLP) and by the neutralization test (NT). PCR-RFLP was performed using a combination of endonucleases such as HhaI, AluI, and HaeIII. Of the 94 PCR-positive samples, the serotypes of 91 (96.8%) were identified by PCR-RFLP analysis (adenovirus 3: 50%, 4: 11%, and 8: 32%). Out of the 115 samples, 60 samples were identified by the neutralization (adenovirus 3, 4, 7, and 8). When both PCR-RFLP and the neutralization techniques were used, 53.2%, 11.7%, 1.1%, and 34% of the samples were identified as adenovirus 3, 4, 7, and 8, respectively. In contrast to the results of a nationwide surveillance report, adenovirus 3 was found as a major cause of keratoconjunctivitis in the Yokohama area. The nationwide surveillance report did not reflect accurately the epidemiological situation in the local area. In order to obtain surveillance data that would be useful for the prevention of an adenovirus conjunctivitis epidemic, it seems that local epidemiology is more important than that nationwide surveillance.

Adenovirus Infections, Human↗
PubMed2006

Dispersion stability of TiO2 nanoparticles covered with SiOx monolayers in water.

The repetition of a two-step route consisting of chemisorption of 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) and its subsequent photooxidation has formed SiOx monolayers on the surfaces of TiO2 particles layer by layer (SiOx(n < or = 4)/TiO2, n = repeated number). The trace of these processes using diffuse reflectance FT-IR and solid-state 29Si NMR spectroscopy reveals that TMCTS is chemisorbed on TiO2 through Ti-O-Si bonds followed by growth of Si-O-Si networks via dehydration-condensation of the Si-OH groups generated by TiO2 photocatalytic oxidation of the Si-H and Si-CH3 groups. The point of zero charge of the TiO2 particles decreases from 6.5 to 5.4 at n = 1, reaching 4.9 at n2. As a result of coverage with the SiOx monolayers, the dispersion stability of TiO2 particles in neutral water is significantly improved without changing their optical properties. The dispersion stability further increases with accumulation of SiOx monolayers.

Journal Article↗
PubMed2006

Genetic characterization of group A rotavirus strains circulating among children with acute gastroenteritis in Japan in 2004-2005.

A total of 752 fecal specimens collected from July 2004 to June 2005 from children with acute gastroenteritis in four localities in Japan (Maizuru, Tokyo, Sapporo, and Osaka) were screened for group A rotavirus by RT-PCR. It was found that 82 (10.9%) specimens were positive for group A rotavirus. The G-(VP7 genotypes) and P-(VP4 genotypes) types were further investigated. The P-types of 18 rotavirus strains, which could not be typed by RT-PCR, were determined by sequencing analysis. Of these, 94% (17/18) were P[8] with multiple point mutations at the VP4 primer-binding site. Another sample turned out to be a rare genotype P[9], which was closely related to feline rotavirus. The predominant genotype was G1P[8] (46.4%), followed by G3P[8] (32.9%) and G2P[4] (12.2%). A number of unusual combinations including, G1P[4] (1.2%), G2P[8] (1.2%), G3P[9] (1.2%), G1G3P[8] (1.2%), and G2G3P[8] (3.7%), were also detected. A new nomenclature of P[8] was proposed, in which worldwide rotavirus P[8] strains were classified into four sub-lineages, namely IA, IB, IIA, and IIB. A wide range of amino acid substitutions (up to 22) specific for P[8] lineages and sub-lineages were also identified. Interestingly, only short amino acid motifs located at positions 32-35, 121-135, and 195-236 of VP4 correctly defined the phylogenetic P[8] lineages and sub-lineages. Of note, at least two distinct clusters of rotavirus P[8] were co-circulating in the Japanese pediatric population studied.

Acute Disease↗
PubMed2006

Phylogenetic analysis of envelope glycoprotein (E1) gene of rubella viruses prevalent in Japan in 2004.

We performed a molecular epidemiological study on the envelope glycoprotein gene (E1 gene) obtained by PCR amplification from specimens of 17 rubella patients in certain areas (Gunma, Saitama, and Kagoshima prefectures, and Tokyo metropolitan area) in Japan in 2004. In these sequences of partially amplified DNAs (283 bases) within the E1 gene, no nucleotide substitution was observed. They were classified into genotype 1D of clade 1 in the constructed phylogenetic tree. One amino acid substitution was found between the amino acid sequence predicted from these DNAs and those of Japanese strains [To-336 vaccine strain (To-336 vac) and its wild progenitor (To-336 wt)]. The results suggest that the rubella viruses (RV) prevalent in certain areas of Japan in 2004 were highly homologous and were closely related with Japanese vaccine strain.

Adolescent↗
PubMed2006

[Food borne outbreak caused by the well water contaminated norovirus].

In May 2004, 65 people from 18 groups of visitors to guesthouse (a traditional Japanese guesthouse) in the Nagano Prefecture, Japan developed acute gastroenteritis. Although these cases originally attributed to food poisoning, based on epidemiological and dietary surveys, there was nothing that is associated as a cause food. The same wall water was used throughout the guesthouse except in the kitchen, so testing was conducted on this water. Lordsdale variant strain of Norovirus was detected from both of the well water and the feces of patients and staff. The well supplying to the guesthouse was only 10 meters deep and fecal coliform group was also detected in the well water from the guesthouse. This suggested that the water source was contaminated by human feces.

Acute Disease↗
PubMed2005

Genotyping of Norovirus strains detected in outbreaks between April 2002 and March 2003 in Osaka City, Japan.

Noroviruses (NVs) are the major cause of food- and waterborne nonbacterial gastroenteritis in Japan. Between April 2002 and March 2003, a total of 111 fecal specimens from 40 outbreaks of acute nonbacterial gastroenteritis in Osaka City, Japan were subject to NV detection. Seventy-two samples (64.9%) from 31 outbreaks (77.5%) were NV positive by a real time reverse transcription (RT)-PCR assay. To further determine the genotype of individual NV strains, we sequenced the capsid N-terminal/shell (N/S) domain of some representative strains from each outbreak. The 51 NV strains detected in this study were segregated into 15 genotypes (6 in genogroup I and 9 in genogroup II), and GII/5 genotype NV was a dominant outbreak genotype.

Caliciviridae Infections↗
PubMed2005

Multiprefectural spread of gastroenteritis outbreaks attributable to a single genogroup II norovirus strain from a tourist restaurant in Nagasaki, Japan.

A series of gastroenteritis outbreaks caused by noroviruses (NVs) among tourist groups from several prefectures was associated with eating a lunch prepared by a restaurant in Nagasaki City, Japan, on 18 and 19 November 2003. A retrospective cohort study was performed to estimate the magnitude of the outbreak and identify the source of infection. Epidemiological information was obtained through the local public health centers in the areas where the illness occurred. Stool and vomit specimens and food and environmental samples were analyzed by reverse transcription-PCR with genogroup-specific primers. Positive samples were sequenced and analyzed phylogenetically. Of 1,492 tourists who ate a lunch prepared by the restaurant during the 2-day period, 660 (44.2%) developed illness, with an average incubation time of 31.2 h. Whereas NVs were not detected in any food samples, identical sequences most closely related to the Mexico genotype of genogroup II NV were found in specimens from case patients, restaurant staff, and the kitchen table. Food handlers were concluded to be the source of the outbreak as a result of the contamination of several meals. The series of outbreaks described here exemplifies the role of tourism as a contemporary way to distribute a single infectious agent to multiple and geographically remote areas.

Adolescent↗
PubMed2004

Human astrovirus, norovirus (GI, GII), and sapovirus infections in Pakistani children with diarrhea.

Fecal specimens from 517 infants and young children admitted to the Civil Karachi Hospital, Dow Medical College, Karachi city, Pakistan with acute gastroenteritis from 1990 to 1994 were collected and screened by RT-PCR for human astrovirus (AstV), norovirus (NV), and sapovirus (SV). The specific epidemiological data for illness caused by these viruses in Pakistan are not available. AstV, NV, and SV were detected in 58, 51, and 17 of 517 fecal specimens, and this represented 11.2, 9.9, and 3.2%, respectively. An outbreak of gastroenteritis attributable to AstV serotype 1 was identified during September and October 1990. Moreover, one specimen with a triple mixed infection between AstV (serotypes 1 and 3) and NV GII was found. NV and SV were subjected to molecular analysis by sequencing. One of the sequenced specimens positive for SV turned out to be similar to a strain tentatively called a genogroup IV. The result underscores the importance of these viruses in association with acute gastroenteritis in Karachi city, Pakistan.

Astroviridae Infections↗
PubMed2004

Evaluation of a bedside immunochromatographic test for detection of adenovirus in respiratory samples, by comparison to virus isolation, PCR, and real-time PCR.

An immunochromatography (IC) kit for human adenovirus (HAdV) was evaluated with 138 patient nasopharyngeal samples. The samples were collected at a sentinel clinic in Japan from January through June 2003. Patients were diagnosed by clinical manifestation of pharyngoconjunctival fever (n = 38) or exudative tonsillitis (n = 100). The IC kit was positive for 84% (116 of 138) of patients diagnosed at bedside. The remaining extract solution of the IC kit test was transferred into maintenance medium and tested via laboratory diagnoses. The IC kit had 95% sensitivity (116 of 122 patients) with HAdV isolation (isolation) as the standard and 91% sensitivity (116 of 128 patients) with PCR as the standard. All of the IC kit-positive samples were isolation and PCR positive. Similarly, all the isolation-positive samples were PCR positive. Twenty-two IC kit-negative samples were evaluated by real-time PCR. Six samples were IC kit negative and isolation positive and contained 3.8 x 10(7) to 2.5 x 10(9) copies of the HAdV genome/ml. Five samples that were only PCR positive contained 3.0 x 10(4) to 3.8 x 10(5) copies of the HAdV genome/ml, but one sample was real-time PCR negative. We conclude that the IC kit is a useful bedside diagnostic tool for HAdV infections because it has 95% sensitivity (compared to isolation), but a negative result does not always rule out HAdV infection.

Adenovirus Infections, Human↗
PubMed2004

Characterizations of adenovirus type 41 isolates from children with acute gastroenteritis in Japan, Vietnam, and Korea.

Genetic and antigenic characterizations of 70 strains of adenovirus type 41 (Ad41), isolated between 1998 and 2001 from children in Japan, Vietnam, and Korea, were done by DNA restriction enzyme (RE) analysis, sequencing analysis, and monoclonal antibody (MAb)-based enzyme-linked immunosorbent assay (ELISA). Eight genome types were observed in the present study, among which D25, D26, D27, and D28 were novel genome types. These eight genome types were divided into two genome-type clusters (GTCs) based on phylogenetic analysis of the hypervariable regions (HVRs) of the hexon. GTC1 includes D1, D25, D26, D27, and D28, and the GTC2 contains D4, D12, and D22. The amino acid homologies among the members within a GTC were 97 to 100%, whereas between the members of different GTCs the homologies were 92 to 94%. The specificity of the GTC classification was confirmed by ELISA with MAb 1F, which was selected by the Ad41 prototype Tak strain. It was found that only the isolates of GTC1 but not of GTC2 reacted with MAb 1F. These results suggest that Ad41 isolates from the three countries should be classified into two subtypes. The accumulation of amino acid mutations located in HVRs of hexon are indicative for the classification of Ad41 subtype.

Acute Disease↗
PubMed2003

Epidemiological features of rotavirus infection among hospitalized children with gastroenteristis in Ho Chi Minh City, Vietnam.

An epidemiological study of the G serotype and P genotype distribution of group A rotaviruses by using ELISA and/or RT-PCR was conducted in children (aged 1 month to 15 years) with diarrhea that were admitted to the General Children's Hospital No. 1, Ho Chi Minh City, Vietnam from December 1999 to November 2000. The results showed that rotavirus is associated with 65.6% (889/1355) of diarrheal admissions. Rotavirus infection mostly affected children under 2 years of age with a peak incidence in children 1 to 2 years of age (75.7%) and it occurs year round with a slight seasonal pattern; 99.5% of the specimens could be G-typed: G1 was predominant (68.7%), followed by G4 (15.4%), G2 (12.3%), G3 (0.6%), and G9 (0.5%). High identities of VP7 nucleotide (96.3 to 96.9%) and deduced amino acid (98.1 to 98.4%) were found between two Vietnamese G9 strains and also the recent emergence of G9 strains US 1205, Brazilian R143, and Malawian MW69. Mixed infections were identified in 17 (2.0%), and 5 strains (0.5%) remained untypable. The four most common worldwide strains, G1P[8], G2P[4], G3P[8], and G4P[8], constituted 81.1% of all rotaviruses typed with G1P[8] being the most prevalent type (58.2%). Unusual G/P combinations (11 strains) were detected in 11.7% of all strains, of which, G1P[4] was the most prevalent, accounting for 5.6% of the total. Several combinations of G and P types were observed in this study, suggesting a complex rotavirus infection pattern in Vietnam. This study has provided for the first time clear indication on the circulating G and P genotypes among hospitalized children in Ho Chi Minh City, Vietnam. The results suggest that these viral infections are prevalent among hospitalized children and that the four most common worldwide G types as well as the four most common G-P combinations were also infecting children in Ho Chi Minh City, Vietnam. This result could have important implications for rotavirus vaccine programs and for understanding the epidemiological characteristics of human rotavirus in Ho Chi Minh City, Vietnam.

Adolescent↗
PubMed2003

Detection of norovirus (GI, GII), Sapovirus and astrovirus in fecal samples using reverse transcription single-round multiplex PCR.

A reverse transcription (RT) single-round multiplex polymerase chain reaction (smPCR) assay was developed to detect simultaneously Norovirus genogroup I and II, Sapovirus and astrovirus. A total of 377 diarrhea stool samples (screened for rotavirus- and adenorivus-negative) from four regions in Japan during July 2000 to June 2001 were examined by RT-smPCR. The positive rate was 16.4% (62 out of 377 stool samples). Norovirus, Sapovirus and astrovirus were detected in 42, 16, 4 of 60 positive samples, respectively. Coinfection was not found in these samples. Infections occurred mainly in November, December and January. The key elements of the RT-smPCR are (i) the cDNA synthesis with the Superscript RTII and random primer at 42 degrees C for 1 h, at 99 degrees C for 5 min, and (ii) single-round multiplex PCR by using Taq polymerase mixed together with a mixture of four different primer pairs (G1-SKF/G1-SKR for Norovirus genogroup I, COG2F/G2-SKR for Norovirus genogroup II, SLV5317/SLV5749 for Sapovirus, PreCAP1/82b for astrovirus). All of the four primer pairs amplify the capsid region of target viral genome, produce four size-specific amplicons of 330, 387, 434, 719 bp for Norovirus genogroup I and II, Sapovirus and astrovirus, respectively. This assay provides a more rapid and efficient way to detect these viruses from fecal samples in a single test, and also offers the potential for their molecular detection in food and environmental samples.

Adolescent↗
PubMed2003

[A food poisoning outbreak caused by purple Washington clam contaminated with norovirus (Norwalk-like virus) and hepatitis A virus].

A party of 57 people dined together in a restaurant in Hamamatsu City on December 11, 2001. The next day, 22 of them developed symptoms of acute gastroenteritis, such as diarrhea, vomiting, and fever. Examination of 4 fecal specimens from these patients by ELISA for Norovirus (Norwalk-like virus, NV) detected both genogroup I (GI) and genogroup II (GII) NV in all the 4 specimens. In addition, RT-PCR and real-time PCR methods for NV detected the NV gene. Approximately one month after the outbreak of the food poisoning (acute gastroenteritis) by NV, 4 individuals in the same party developed type A hepatitis. Both RT-PCR and real-time PCR methods for hepatitis A virus (HAV) detected the HAV gene in their fecal specimens. The party of these patients ate purple Washington clam (Saxidomus purpuratus, imported from China) steamed with red pepper. Since this food appeared to have caused the viral infections, the one with the same lot number was subjected to viral examinations, which successfully detected the NV GI, NV GII, and HAV genes. These results led to the conclusion that the clam contaminated with NV and HAV had caused the food poisoning. The DNA sequences of the NV detected in the patients and the clam had 74 to 99% homology, indicating strains of various genotypes. All the strains of HAV that were derived from the patients and the clam were genotype 1A, and these sequences had over 95% homology, but were not completely identical. This outbreak led to the demonstration of imported fishery products as a cause of type A hepatitis, and indicated the need for guiding and enlightening people on the importance of adequate cooking of bivalves.

Animals↗
PubMed2003

[Poliovirus uptake into and excretion from oysters: a model experiment for elimination of Norwalk-like viruses from oysters].

Outbreaks of gastroenteritis caused by Norwalk-like viruses are often induced by the consumption of raw shellfish such as oysters. Incidences reach a peak during the cold season in Japan, when seawater temperatures fall below 10 degrees C. We investigated oysters' uptake and excretion of viruses, over varying lengths of exposure, monitoring the effects of changes in temperature and flow rate of seawater, and the presence of plankton. The study was performed using a poliovirus and an experimental circulatory system, which was framed on the same principle as a model practically used for the depuration of oysters. Polioviruses present in the seawater were taken rapidly into the midgut gland of oysters. However, virus levels detected in oysters at both 10 degrees C and 20 degrees C were decreased to approximately 1/1,000 to 1/10,000 within 6 hrs after the circulatory seawater was replaced by UV irradiated seawater. These results demonstrate the effectiveness of the circulatory depuration system for the elimination of poliovirus from oysters, and indicate that controlling the temperature and flow rate of the circulatory system could decrease the risk of NLV infection.

Animals↗
PubMed2003

Detection, quantitation, and phylogenetic analysis of noroviruses in Japanese oysters.

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. Phylogenetic analysis was performed by using the neighbor-joining method. We detected the NV genome in 17 of 191 oysters (9%). Phylogenetic analysis indicated genogroup I (Norwalk virus type) in 3 of the 17 oysters and genogroup II (Snow Mountain virus type) in the other 14. Both genogroups showed wide genetic diversity. To quantify the NV capsid gene in these oysters, we performed real-time PCR using genogroup-specific probes. More than 10(2) copies of the NV genome were detected in 11 of 17 oysters. The results suggested that about 10% of Japanese oysters intended for raw consumption harbored NVs, and more than 50% of those oysters in which NVs were detected had a large amount.

Animals↗