Quang Duy Trinh

Diversity of Human Parechoviruses Isolated from Stool Samples Collected from Thai Children with Acute Gastroenteritis

ABSTRACT A total of 82 fecal specimens which were known to be negative for rotavirus, adenovirus, norovirus, sapovirus, and astrovirus and which were collected from infants and children with acute gastroenteritis in Chiang Mai, Thailand, from January to December 2005 were screened for human parechovirus (HPeV). HPeV was detected by reverse transcription-PCR with a primer pair that amplified the 5′ untranslated region of its genome and was genotyped by sequencing of the VP1 region. HPeV was detected in 12 of 82 specimens tested, and the detection rate was found to be 14.6%. The capsid VP1 gene was successfully sequenced from nine of the HPeV strains detected. The HPeV strains studied clustered into four different genotypes, HPeV genotype 1 (HPeV1) to HPeV4, and the majority of the strains studied (five strains) belonged to HPeV1. This is the first finding of HPeV from children with acute gastroenteritis in Thailand. In addition, the diversity of the Thai HPeV strains was also noted.

Human Parechovirus Infection in Children Hospitalized with Acute Gastroenteritis in Sri Lanka

ABSTRACT Of 362 fecal specimens collected from infants and children hospitalized with acute gastroenteritis in Sri Lanka from September 2005 to August 2006, 30 (8.3%) were positive for human parechovirus (HPeV). Six different HPeV genotypes, including HPeV1, -3, -4, -5, -10, and -11, were identified, of these, HPeV11 was reported for the first time.

A novel RT-multiplex PCR for detection of Aichi virus, human parechovirus, enteroviruses, and human bocavirus among infants and children with acute gastroenteritis.

A novel reverse transcription-multiplex polymerase chain reaction assay was developed to detect Aichi virus, human parechovirus, enteroviruses, and human bocavirus. A mixture of four pairs of published specific primers, 6261 and 6779, ev22(+) and ev22(-), F1 and R1, 188F and 542R, was used to amplify the viral genomes and specifically generate four different amplicon sizes of 519, 270, 440, and 354 bp for Aichi virus, human parechovirus, enteroviruses, and human bocavirus, respectively. A total of 247 fecal specimens previously screened for rotavirus, adenovirus, norovirus, sapovirus, and astrovirus-negative, collected from infants and children with acute gastroenteritis in Japan from July 2007 to June 2008, were tested further for the presence of the four viruses, Aichi virus, human parechovirus, enteroviruses, and human bocavirus, by RT-multiplex PCR. The total detection rate of these viruses was 26.7% (66 out of 247 samples). Of these, HPeV, EVs, and HBoV were identified in 20, 41, and 5 specimens. No Aichi virus was found among these subjects. The sensitivity and specificity of RT-multiplex PCR were assessed and demonstrated a strong validation against RT-monoplex PCR. This is the first report of detecting these types of viruses in fecal samples from infants and children with acute gastroenteritis by RT-multiplex PCR.

Novel Human Parechovirus, Sri Lanka

Of 362 fecal samples collected from children with acute gastroenteritis in Sri Lanka during 2005–2006, 30 (8.3%) were positive for human parechovirus (HPeV) by reverse transcription–PCR. A novel HPeV, designated as HPeV10, was identified in 2 samples by sequence analysis of the viral protein 1 gene of the detected HPeVs.

Emergence of rare sapovirus genotype among infants and children with acute gastroenteritis in japan

A total of 1,154 fecal specimens from infants and children with acute gastroenteritis in five cities in Japan (Maizuru, Tokyo, Sapporo, Saga, and Osaka), collected from July 2003 to June 2005, were tested for the presence of diarrheal viruses by reverse transcriptase multiplex PCR. Overall, 469 of 1,154 (40.6%) were positive for diarrheal viruses, of which 49 (10.4%) were positive for sapovirus. The peak of sapovirus infection shifted from April–June in 2003–2004 to October–December in 2004–2005. The observations show that maximum sapovirus prevalence can occur during warmer seasons. Sapovirus was subjected to molecular genetic analysis by sequencing. The results indicated that sapovirus genogroup I was a dominant group (100%). Sapovirus strains detected in this study were further classified into four genotypes (GI/1, GI/4, GI/6, and GI/8). Of these, sapovirus GI/1 was the most predominant, followed by sapovirus GI/6; these accounted for 93% (13 of 14) and 7% (1 of 14), respectively, in 2003–2004. However, it was noteworthy that sapovirus GI/6 suddenly emerged to become the leading genotype, accounting for 77% (27 of 35) of isolates in 2004–2005. This is believed to be the first report of the changing distribution of sapovirus genotypes and of the emergence of the rare sapovirus GI/6.

Human bocavirus infection in children with acute gastroenteritis in Japan and Thailand.

A total of 329 fecal specimens, which had been known to be negative for rotavirus, adenovirus, norovirus, sapovirus, and astrovirus, and which were collected from infants and children with acute gastroenteritis in Japan and Thailand during 2005–2008 were screened for human bocavirus (HBoV). HBoV was detected by PCR with a primer pair that amplified the NP1 region of its genome and was genotyped by sequencing of the VP1/VP2 region. Of the 329 samples tested, 6 (1.8%) were positive for HBoV. Of these, five samples were collected from Japan and one sample was from Thailand, and the detection rates of HBoV in each country were 2% and 1.2%, respectively. For the detected HBoV, the capsid VP1/VP2 gene of all HBoV strains was successfully sequenced. Four Japanese HBoV strains studied were clustered into group 1, while the remaining Japanese strain and a unique Thai strain belonged to group 2. No severe acute gastroenteritis associated with HBoV was noted. This study provides better understanding on the epidemiology of HBoV infections in children with acute gastroenteritis in Japan and Thailand. J. Med. Virol. 83:286–290, 2011.

Sequence Analysis of the VP7 Gene of Human Rotaviruses G2 and G4 Isolated in Japan, China, Thailand, and Vietnam During 2001-2003

Sequence and phylogenetic analyses of the rotavirus VP7 gene were performed on 52 human G2 and G4 strains isolated in Japan, China, Thailand, and Vietnam during 2001–2003. All genotype G2 strains included in the study clustered into lineage II of the phylogenetic tree, together with the majority of global G2 strains detected since 1995. The amino acid substitution at position 96 from aspartic acid to asparagine was noted among the emerging or re‐emerging G2 rotavirus strains in Japan, Thailand, and Vietnam during 2002–2003. Genotype G4 strains detected in Vietnam grouped into lineage Ia of the phylogenetic tree, whereas Japanese G4 strains clustered in lineage Ic which included emerging G4 strains from Argentina, Italy, Paraguay, and Uruguay. It is noteworthy that an insertion of asparagine was found at position 76 in all the Japanese strains and that its presence might be involved in the emergence of G4 rotavirus in Japan during 2002–2003. J. Med. Virol. 82: 878–885, 2010.

Sequence analysis of the capsid gene of Aichi viruses detected from Japan, Bangladesh, Thailand, and Vietnam.

Sequence analysis of the capsid gene of Aichi viruses was performed on 12 strains detected in Japan, Bangladesh, Thailand, and Vietnam during 2002–2005. The phylogenetic tree constructed from 17 nucleotide sequences of the capsid gene of the strains studied and reference strains demonstrated that Aichi virus strains clustered into two branches. A classification of Aichi viruses based on the capsid gene was proposed, in which lineage I consists of the Aichi virus strains detected from Japan, Thailand, Vietnam, and Germany, and lineage II includes Bangladeshi strains and a Brazilian strain. J. Med. Virol. 80: 1222–1227, 2008.

H3N2 influenza A virus replicates in immortalized human first trimester trophoblast cell lines and induces their rapid apoptosis.

Problem  Epidemiological data suggested that pandemic influenza increased the risks of spontaneous abortion and premature labor, while seasonal influenza also increased the risk of schizophrenia in adolescence. However, their pathogenesis is so far unknown.

Poly I:C induces collective migration of HaCaT keratinocytes via IL-8

BackgroundDelayed wound healing reduces the quality of life (QOL) of patients. Thus, understanding the mechanism of wound healing is indispensable for better management. However, the role of innate immunity in wound healing is thus far unknown. Recently the involvement of TLR3 in wound healing has been evaluated. The systemic administration of polyriboinosinic-polyribocytidylic acid (poly I:C ; a substitute for viral dsRNA and a ligand of toll-like receptor 3), enhances wound healing in vivo. The aim of this study is to improve our understanding of the link between innate immunity and human wound healing, particularly in re-epithelialization.ResultsThe present study showed that poly I:C significantly accelerated collective HaCaT cell migration in a scratch assay. Poly I:C also increased IL-8 and bFGF production, and anti-IL-8 antibodies significantly inhibited the migration caused by poly I:C. Human recombinant IL-8 also accelerated collective HaCaT cell migration. An immunofluorescence assay and enzyme-linked immunosorbent assay (ELISA) also revealed that poly I:C decreased E-cadherin protein levels and increased vimentin protein levels, and anti-IL-8 antibody reversed this effect. In contrast, nucleic/cytosolic protein ratios of Snail 1 were unchanged in all tested conditions.ConclusionOur findings demonstrated that poly I:C accelerated collective HaCaT cell migration via autocrine/paracrine secretions of IL-8 and the subsequent incomplete epithelial-mesenchymal transition (EMT). Our findings provide a new strategy for wound healing by regulating innate immune systems in re-epithelialization.