Human astrovirus (HAstV) is one of the leading causes of actue virual diarrhea in infants. HAstV-induced epithdlial cell apoptosis plays an important role in the pathogenesis of HAstV infection. Our previous study indicated that HAstV non-structural protein nsPla C-terminal protein nsPla/4 was the major apoptosis functional protein and probably contained the main apoptosis domains. In order to screen for astrovirus encoded apoptotic protien, nsPla/4 and six turncated proteins, which possessed nsPla/4 protein different function domain ,were cloned into green fluorescent protein (GFP) vector pEG-FP-N3. After 24-72 h transfection, the fusion protein expression in BHK21 cells, was analysis by fluorescence microscope and Western blot. The results indicated seven fusion proteins were observed successfully in BHK21 cell after transfected for 24 h. Western blot analysis showed that the level of fusion protein expressed in BHK21 cells was increased significantly at 72h compared to 48h in transfected cells. The successful expression of deletion mutants of nsPla/4 protein was an important foundation to gain further insights into the function of apoptosis domains of nsPla/4 protein and it would also provide research platform to further confirm the molecule pathogenic mechanism of human astrovirus.
Amino Acid Motifs ; Astroviridae Infections ; virology ; Humans ; Mamastrovirus ; genetics ; metabolism ; Mutation ; Sequence Deletion ; Transfection ; Viral Nonstructural Proteins ; chemistry ; genetics ; metabolism

Human astroviruses have been recognized as one of the important causes of viral gastroenteritis in infants and young children. In the present work, we reviewed the progress of astrovirus infections in humans, focusing on the serotypes molecular biological, characteristics of disease, pathogenic mechanism, epidemiology and detection methods, and concluded that there were multiple astroviruses circulating in the world, and several novel astroviruses were discovered in recent years. Human astrovirus 1 was the most prevailing serotype. Which caused intestinal and parenteral infections, and the characteristics of infections were similar to other diarrheal viruses. However, the pathogenic mechanism remained unknown. Only limited data was available about the correlation between the novel astroviruses and diseases, and the laboratory detection methods needed to be established.
Animals ; Astroviridae Infections ; diagnosis ; epidemiology ; pathology ; Cell Line ; Genome, Viral ; genetics ; Humans ; Mamastrovirus ; classification ; genetics ; pathogenicity ; physiology ; Virus Replication

BACKGROUNDThis study was to assess certain epidemiological and clinical characteristics of astrovirus infection in children with diarrhea below 5 years old hospitalized at the Beijing Children's Hospital.

METHODSFrom September 1999 to August 2001, a total of 288 children with diarrhea below 5 years old hospitalized at Beijing Children's Hospital were studied. Fecal specimens collected from each patient were tested for astrovirus by using enzyme immunoassay (EIA) and further serotyped by reverse-transcription polymerase chain reaction (RT-PCR) using serotype-specific primers.

RESULTSAstrovirus antigen was positive in 9.0% of the patients, and the rate of coinfection with rotavirus was 19.2% among the astrovirus positive patients. The patients with astrovirus infection were at the age of 7 days to 17 months, most (92.3%) of them were less than 12 months. Astrovirus infection occurred mainly between October and March of the following year. Main symptoms included watery stool, vomiting, fever, and dehydration. Increased activity of myocardial enzyme was seen in 4 patients. Of the 22 astrovirus positive specimens, 14 were successfully serotyped by RT-PCR and they were all serotype 1.

CONCLUSIONSThe overall incidence of astrovirus infection in young children with diarrhea hospitalized at the Beijing Children's Hospital was 9.0%. The predominant serotype was type 1. Astrovirus may play an important role in viral diarrhea in young children in Beijing, China.

Astroviridae Infections ; diagnosis ; epidemiology ; China ; epidemiology ; Diarrhea ; virology ; Feces ; virology ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Mamastrovirus ; immunology ; isolation & purification ; Serotyping

The prevalence of human astroviruses was tested in patients with acute gastroenteritis by using conventional duplex reverse transcription (RT)-PCR and electrophoresis. Diarrheal fecal samples were collected from 9,597 patients at local hospitals in Seoul. The prevalence of astroviruses was 1.0% (94/9,597 patients; mostly infants), and that of sapoviruses was 0.1% (14/9,597 patients). Age- and gender-wise analyses were carried out on 29 astrovirus-positive patients having complete information on file regarding their age, gender, and other particulars. The results were higher in patients of ages 0 to 14 yr, and 69.0% of the astrovirus-positive patients were females, of which 69.2% were infants (0 to 12 months), and 61.5% were 1-4 yr old. Notably, in the case of 5 to 78-yr-old acute gastroenteritis patients, 100% were females.
Acute Disease ; Adolescent ; Adult ; Age Factors ; Aged ; Astroviridae Infections/complications/*epidemiology/virology ; Child ; Child, Preschool ; DNA, Viral/analysis ; Feces/virology ; Female ; Gastroenteritis/complications/*diagnosis ; Humans ; Infant ; Male ; Mamastrovirus/genetics/*isolation & purification ; Middle Aged ; Prevalence ; Reverse Transcriptase Polymerase Chain Reaction ; Sapovirus/genetics/isolation & purification ; Sex Factors ; Young Adult

A molecular study of intestinal samples from 21 broiler flocks with a history of enteritis revealed that 23.8% and 14.3% were positive for chicken astrovirus (CAstV) and avian rotavirus (ARV), respectively. CAstV and group A ARV were simultaneously detected in only one broiler flock. Birds in this group developed the significant intestinal lesions characterized by frothy contents, paleness, and thin intestinal walls. In this report we present an unusual case of runting stunting syndrome (RSS) with a history of high mortality and growth retardation in broiler chickens. We also make the first identification of CAstV and group A ARV in broiler chickens in Korea.
Animals ; Astroviridae Infections/diagnosis/epidemiology/*veterinary/virology ; Avastrovirus/classification/*genetics/isolation & purification/metabolism ; *Chickens/growth & development ; Enteritis/diagnosis/pathology/veterinary/virology ; Intestines/pathology/virology ; Molecular Sequence Data ; Phylogeny ; Poultry Diseases/*diagnosis/epidemiology/virology ; Republic of Korea/epidemiology ; Rotavirus/classification/*genetics/isolation & purification/metabolism ; Rotavirus Infections/diagnosis/epidemiology/*veterinary/virology

OBJECTIVETo study the epidemiology and strain variations of astrovirus infection among children under 5 years of age, hospitalized for acute diarrhea in China.

METHODSInpatients under 5 years of age with acute diarrhea in hospitals of seven provinces between 1998 and 2005 were enrolled in the study Stool specimens were collected and tested for astrovirus using the Dako Amplified IDEIA Astrovirus kits or reverse-transcription polymerase chain reaction (RT-PCR). Genetic identities of the strains were determined using RT-PCR with serotype-specific primers and confirmed by sequencing of the RT-PCR products.

RESULTSA total of 1668 diarrheal stool samples tested for both rotavirus and calicivirus negative were examined. The detection rate of astrovirus infection was 5.5% (91/1668) and the diarrhea cases caused by astrovirus infection could be found in any season of the year but mainly occurred in cold season from October to next January. Astrovirus detection-rates were: 7.4% among infants aged 9-11 months followed by 6.1% in 12-17 month-olds, and 6-8 months 5.6% & 0-2 months 5.6% before 8 months. Over 95% of astrovirus infections occurred in children before 2 years of age. Among 49 strains, typed, serotype 1(45/91) was most commonly seen while serotype 5 was in two cases and serotype 3 and 8 were detected in only one case respectively.

CONCLUSIONAstrovirus seemed an important etiologic agent in young children with acute diarrhea in China and Serotype 1 was the most prevalent one.

Acute Disease ; Astroviridae ; classification ; isolation & purification ; Astroviridae Infections ; complications ; epidemiology ; Child, Preschool ; China ; epidemiology ; DNA, Viral ; analysis ; Diarrhea ; virology ; Humans ; Infant ; Infant, Newborn ; Inpatients ; Reverse Transcriptase Polymerase Chain Reaction ; Seasons ; Serotyping

Currently, there are a few reports on viral coinfection that causes an acute watery diarrhea in Korean children. So, to evaluate the features of coinfectious viral agents in children with acute watery diarrhea, we enrolled 155 children with acute watery diarrhea from July 2005 to June 2006. Fecal samples were collected and evaluated for various viral infections such as rotavirus, norovirus, adenovirus and astrovirus. The mean (+/-standard deviation) age of the children was 2.71+/-2.37 yr. The detection rate of viral agents was most common in children between the ages of 1 and 3 yr. Rotavirus was detected in 63 children (41.3%), norovirus in 56 (36.2%), adenovirus in 11 (7.1%), and astrovirus in 1 (0.6%). Regarding rotavirus, there were 38 (60.3%) cases with monoinfection and 25 (39.7%) with coinfection. For norovirus, there were 33 (58.9%) cases with monoinfection and 23 (41.1%) with coinfection. Coinfection with rotavirus and norovirus was most common, and occurred in 20/155 cases (12.9%) including coinfection with adenovirus. So, rotavirus and norovirus were the most common coinfectious viral agents in our study population with acute watery diarrhea.
Acute Disease ; Adenovirus Infections, Human/epidemiology ; Astroviridae Infections/epidemiology ; Caliciviridae Infections/epidemiology ; Child ; Child, Preschool ; Diarrhea/epidemiology/*virology ; Feces/virology ; Humans ; Infant ; Korea/epidemiology ; Norovirus/isolation & purification ; Rotavirus Infections/epidemiology ; Virus Diseases/complications/*epidemiology/virology

OBJECTIVETo establish a one-step four multiplex reverse transcription polymerase chain reaction (RT-PCR) method based on Homo-Tag Assisted Non-Dimer System (HAND) system for simultaneous detection of 4 diarrhea viruses of rotavirus, astrovirus, norovirus and sapovirus.

METHODSPrimers were designed according to the conserved genome sequence of the 4 viruses and the homologous tail sequences were added to the 5' end. The multiplex RT-PCR system was constructed by optimizing the PCR parameters such as the concentration of universal tag primer and genome-specific Homo-Tailed primers. The specificity, stability and sensitivity of the method were evaluated systematically.

RESULTSThe 4 multiplex RT-PCR methods based on HAND system was established successfully. Specificity analysis showed no cross reaction between the 4 diarrhea viruses. The sensitivity analysis showed detection limits for rotavirus, astrovirus, norovirus and sapovirus of 48, 1.92, 9.6 and 48 pg per reaction, respectively.

CONCLUSIONThe established HAND system-based multiplex RT-PCR assay allows simple, rapid, specific, sensitive, and stable for detection of the 4 common diarrhea viruses at low costs and is suitable for application in general medical laboratories.

Astroviridae ; genetics ; isolation & purification ; Diarrhea ; virology ; Feces ; virology ; Humans ; Multiplex Polymerase Chain Reaction ; methods ; Norovirus ; genetics ; isolation & purification ; RNA, Viral ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Rotavirus ; genetics ; isolation & purification ; Sapovirus ; genetics ; isolation & purification

To investigate epidemiologic feature and genetic variance of Sapovirus among children in China, fecal specimens were collected from children under 5 years old with acute diarrhea from Feb 2006 to Jan 2007 in nine provinces including Anhui, Fujian et al. A total of 1,110 fecal samples were detected for Sapovirus by reverse transcriptase-PCR (RT-PCR). Ten samples (0.9%) were positive for Sapovirus. The PCR products were then sequenced and analysed by phylogenetic tree. The results indicated that the detected Sapovirus strains were classified into two genogroups and three genotypes, including G I/1, G I/3, G II/3.
Astroviridae Infections ; epidemiology ; etiology ; genetics ; Base Sequence ; Caliciviridae Infections ; epidemiology ; China ; epidemiology ; Diarrhea ; classification ; virology ; Feces ; virology ; Gastroenteritis ; epidemiology ; etiology ; virology ; Genetic Variation ; Humans ; Molecular Sequence Data ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; Sapovirus ; classification ; genetics

Astroviruses are widely detected in pigs but their detection in wild boars is rather sporadic. In this study, astroviruses were detected in organ homogenates of wild boars by applying nested reverse transcriptase polymerase chain reaction, and the typing was carried out by phylogenetic analysis. Overall, 30/200 (15.0%) homogenates were positive for astroviruses. Genetic typing revealed that of 13 amplicons analyzed, 8 were typed as porcine astrovirus lineage 2 (PAstV-2), 2 as lineage 4 (PAstV-4), 2 identical sequences were grouped with chicken astrovirus, and 1 sequence belonged to a bat astrovirus lineage. This first identification of chicken and bat astroviruses in wild boars indicates interspecies transmission.
Avastrovirus ; Chickens ; Reverse Transcriptase Polymerase Chain Reaction ; Sus scrofa ; Swine