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Viruses May 2023The enteric chicken astrovirus (CAstV) and avian nephritis virus (ANV) are the type species of the genus (AAstV; family), capable of causing considerable production...
The enteric chicken astrovirus (CAstV) and avian nephritis virus (ANV) are the type species of the genus (AAstV; family), capable of causing considerable production losses in poultry. Using next-generation sequencing of a cloacal swab from a backyard chicken in Tanzania, we assembled genome sequences of ANV and CAstV (6918 nt and 7318 nt in length, respectively, excluding poly(A) tails, which have a typical AAstV genome architecture (5'-UTR-ORF1a-ORF1b-ORF2-'3-UTR). They are most similar to strains ck/ANV/BR/RS/6R/15 (82.72%) and ck/CAstV/PL/G059/14 (82.23%), respectively. Phylogenetic and sequence analyses of the genomes and the three open reading frames (ORFs) grouped the Tanzanian ANV and CAstV strains with Eurasian ANV-5 and CAstV-Aii viruses, respectively. Compared to other AAstVs, the Tanzanian strains have numerous amino acid variations (substitutions, insertions and deletions) in the spike region of the capsid protein. Furthermore, CAstV-A has a 4018 nt recombinant fragment in the ORF1a/1b genomic region, predicted to be from Eurasian CAstV-Bi and Bvi parental strains. These data should inform future epidemiological studies and options for AAstV diagnostics and vaccines.
Topics: Animals; Avastrovirus; Tanzania; Phylogeny; Astroviridae Infections; Astroviridae; Chickens; Poultry Diseases
PubMed: 37376547
DOI: 10.3390/v15061247 -
Journal of Infection and Public Health Aug 2023Human astrovirus (HAstV) infection is one of the leading causes of acute gastroenteritis in young children. The present study reports the outbreak of HAstV in children...
BACKGROUND
Human astrovirus (HAstV) infection is one of the leading causes of acute gastroenteritis in young children. The present study reports the outbreak of HAstV in children with acute gastroenteritis in Kyoto, Japan, during the COVID-19 pandemic, 2021.
METHODS
A total of 61 stool samples were collected from children with acute gastroenteritis who visited a pediatric outpatient clinic in Maizuru city, Kyoto, Japan from July to October, 2021. HAstV was screened by RT-PCR, and the genotypes were identified by nucleotide sequence analysis.
RESULTS
Of 61 cases of acute gastroenteritis, 20 were mono-infected with HAstV alone. In addition, mixed infection of HAstV and NoV, and HAstV and RVA were also detected in 15 and 1 cases, respectively. Of 36 HAstV strains detected in this outbreak, 29 and 7 were HAstV1 and MLB2 genotypes, respectively. All HAstV1 strains were closely related to the HAstV1 reported from Thailand and Japan in 2021 and all of them belonged to subgenotype HAstV1a. Among MLB2, they were most closely related to the MLB2 strains reported from China in 2016 and 2018.
CONCLUSIONS
After the kindergartens and schools were re-opened at the middle of 2021 in Japan, an outbreak of HAstV was reported. Control measures against the COVID-19 pandemics might affect the spread of diarrheal virus infection. Here we report the outbreak of HAstV1 and MLB2 in Kyoto, Japan, during COVID-19 pandemic in 2021.
Topics: Child; Humans; Infant; Child, Preschool; Mamastrovirus; Japan; Pandemics; COVID-19; Phylogeny; Feces; Gastroenteritis; Astroviridae Infections; Genotype
PubMed: 37336127
DOI: 10.1016/j.jiph.2023.05.034 -
Research in Veterinary Science Aug 2023Astroviruses have been identified in a wide variety of animal species and are associated with gastro-intestinal disease in humans. Pathologies due to extra-intestinal...
Astroviruses have been identified in a wide variety of animal species and are associated with gastro-intestinal disease in humans. Pathologies due to extra-intestinal localization are known in different hosts. We report the detection of astroviruses in synanthropic squamate reptile species (Podercis siculus and Tarentola mauritanica). Fecal samples were collected from 100 squamates from urban and peri-urban areas of three regions in South Italy and tested for the presence of astroviruses using a broadly reactive (pan-astrovirus) RT-PCR protocol targeting the RNA-dependent RNA polymerase. Astrovirus RNA was detected in 11% of the samples and for six strains a 3 kb-long fragment at the 3' end of the genome was sequenced, obtaining information on the complete capsid-encoding ORF2 sequence. Viral RNA was also detected in the brain of one of the positive animals. The sequences generated from the astrovirus strains shared low nucleotide identities in the ORF2 (< 43.7%) with other known reptilian astrovirus sequences, hinting to the massive genetic diversity of members of this viral family. Based on the partial RdRp gene of the sequenced strains, however, we observed species-specific patterns, regardless of the geographic origin of the animals, and we also identified a possible inter-species transmission event between geckoes and lizards.
Topics: Humans; Animals; Astroviridae Infections; Astroviridae; RNA Viruses; RNA, Viral; Genome, Viral; Phylogeny
PubMed: 37331242
DOI: 10.1016/j.rvsc.2023.06.009 -
Poultry Science Aug 2023Goose astrovirus genotype 2 (GAstV-2) is the causative agent causing severe visceral gout and joint gout in goslings, with mortality rates of affected flocks up to 50%....
Goose astrovirus genotype 2 (GAstV-2) is the causative agent causing severe visceral gout and joint gout in goslings, with mortality rates of affected flocks up to 50%. To date, continuous GAstV-2 outbreaks still pose a great threat to goose industry in China. Although most researches on GAstV-2 have focused on its pathogenicity to geese and ducks, limited studies have been performed on chickens. Herein, we inoculated 1-day-old specific pathogen-free (SPF) White Leghorn line chickens with 0.6 mL of GAstV-2 culture supernatant (TCID 10/0.1 mL) via orally, subcutaneously and intramuscularly, and then assessed the pathogenicity. The results revealed that the infected chickens presented depression, anorexia, diarrhea, and weight loss. The infected chickens also suffered from extensive organ damage and had histopathological changes in the heart, liver, spleen, kidney, and thymuses. The infected chickens also had high viral load in tissues and shed virus after the challenge. Overall, our research demonstrates that GAstV-2 can infect chickens and adversely affect the productivity of animals. And the viruses shed by infected chickens can pose a potential risk to the same or other domestic landfowls.
Topics: Animals; Geese; Chickens; Astroviridae Infections; Virulence; Poultry Diseases; Avastrovirus; Gout; Genotype; China; Phylogeny
PubMed: 37302333
DOI: 10.1016/j.psj.2023.102808 -
Poultry Science Aug 2023The emergence of Goose astrovirus (GoAstV) has led to the gout in geese. This study aimed to isolate and identify the GoAstV from diseased goslings in Sichuan Province,...
The emergence of Goose astrovirus (GoAstV) has led to the gout in geese. This study aimed to isolate and identify the GoAstV from diseased goslings in Sichuan Province, China, followed by performing whole genome phylogenetic analysis of the isolate. The GoAstV was successfully isolated by inoculating the diseased gosling liver and kidney homogenate into the 11-day-old goose embryo allantoic cavity for 3 passages, and the isolate was named as GoAstV-C2 strain. The virus particles were spherical, without capsule, and the size was about 28 nm under transmission electronic microscope. The complete genome length of GoAstV-C2 was 7.035 nt, and the whole genome sequence phylogenetic analysis revealed that it belongs to the GoAstV genotype II (GoAstV-II) subgenotype IIc. The isolated GoAstV-C2 strain was able to be stably passaged in the goose embryo and uric acid sedimentation was observed. The complete genome bioinformation of GoAstV-C2 determined the evolutionary characteristics of the GoAstV isolated from Sichuan, China. This finding lays a foundation for the development of preventive measures, effective vaccines, and therapeutic drugs.
Topics: Animals; Geese; Astroviridae Infections; Phylogeny; Poultry Diseases; Chickens; Avastrovirus; Genotype; China
PubMed: 37300911
DOI: 10.1016/j.psj.2023.102800 -
Mucosal Immunology Aug 2023Astroviruses cause a spectrum of diseases spanning asymptomatic infections to severe diarrhea, but little is understood about their pathogenesis. We previously...
Astroviruses cause a spectrum of diseases spanning asymptomatic infections to severe diarrhea, but little is understood about their pathogenesis. We previously determined that small intestinal goblet cells were the main cell type infected by murine astrovirus-1. Here, we focused on the host immune response to infection and inadvertently discovered a role for indoleamine 2,3-dioxygenase 1 (Ido1), a host tryptophan catabolizing enzyme, in the cellular tropism of murine and human astroviruses. We identified that Ido1 expression was highly enriched among infected goblet cells, and spatially corresponded to the zonation of infection. Because Ido1 can act as a negative regulator of inflammation, we hypothesized it could dampen host antiviral responses. Despite robust interferon signaling in goblet cells, as well as tuft cell and enterocyte bystanders, we observed delayed cytokine induction and suppressed levels of fecal lipocalin-2. Although we found Ido animals were more resistant to infection, this was not associated with fewer goblet cells nor could it be rescued by knocking out interferon responses, suggesting that IDO1 instead regulates cell permissivity. We characterized IDO1 Caco-2 cells and observed significantly reduced human astrovirus-1 infection. Together this study highlights a role for Ido1 in astrovirus infection and epithelial cell maturation.
Topics: Animals; Humans; Mice; Astroviridae Infections; Caco-2 Cells; Indoleamine-Pyrrole 2,3,-Dioxygenase; Interferons; Tryptophan
PubMed: 37290501
DOI: 10.1016/j.mucimm.2023.05.011 -
Emerging Microbes & Infections Dec 2023Characterized by high genetic diversity, broad host range, and resistance to adverse conditions, coupled with recent reports of neurotropic astroviruses circulating in...
Characterized by high genetic diversity, broad host range, and resistance to adverse conditions, coupled with recent reports of neurotropic astroviruses circulating in humans, mamastroviruses pose a threat to public health. The current astrovirus classification system based on host source prevents determining whether strains with distinct tropism or virulence are emerging. By using integrated phylogeny, we propose a standardized demarcation of species and genotypes, with reproducible cut-off values that reconcile the pairwise sequence distribution, genetic distances between lineages, and the topological reconstruction of the genus. We further define the various links established by co-evolution and resolve the dynamics of transmission chains to identify host-jump events and the sources from which different mamastrovirus species circulating in humans have emerged. We observed that recombination is relatively infrequent and restricted to within genotypes. The well-known "human" astrovirus, defined here as mamastrovirus species 7, has co-speciated with humans, while there have been two additional host-jumps into humans from distinct hosts. Newly defined species 6 genotype 2, linked to severe gastroenteritis in children, resulted from a marmot to human jump taking place ∼200 years ago while species 6 genotype 7 (MastV-Sp6Gt7), linked to neurological disease in immunocompromised patients, jumped from bovines only ∼50 years ago. Through demographic reconstruction, we determined that the latter reached coalescent viral population growth only 20 years ago and is evolving at a much higher evolutionary rate than other genotypes infecting humans. This study constitutes mounting evidence of MastV-Sp6Gt7 active circulation and highlights the need for diagnostics capable of detecting it.
Topics: Child; Humans; Animals; Cattle; Mamastrovirus; Astroviridae Infections; Astroviridae; Phylogeny; Gastroenteritis; Feces
PubMed: 37222427
DOI: 10.1080/22221751.2023.2217942 -
Archives of Virology May 2023In India, studies on the epidemiological and genetic characteristics of enteric viruses in adults with acute gastroenteritis (AGE) are lacking. In this study, fecal...
In India, studies on the epidemiological and genetic characteristics of enteric viruses in adults with acute gastroenteritis (AGE) are lacking. In this study, fecal samples (n = 110) from adults with acute gastroenteritis in Pune, Western India, were tested for six enteric viruses, and the prevalence of these viruses was as follows: rotavirus A (RVA), 38.5%; enterovirus (EV), 23.1%; astrovirus (AstV), 23.1%; adenovirus (AdV), 7.7%; human bocavirus (HBoV), 7.7%; norovirus (NoV), 0%. Circulation of the RVA G1P[8], G3P[8], G9P[4], CVA-10, echovirus E13, EVC-116, AstV-5, AstV-2, HBoV-1, and AdVC-2 types was observed. When compared to the RotaTeq, Rotarix, and RotaVac vaccine strains, antigenic changes were found in the A, B, C, and F regions of the RVA strains. The circulation of genetically diverse, unusual enteric virus strains, reported here for the first time in adults with acute gastroenteritis, warrants multi-center hospital-based surveillance studies across the country.
Topics: Adult; Humans; Infant; India; Gastroenteritis; Rotavirus; Rotavirus Infections; Viruses; Human bocavirus; Astroviridae; Enterovirus Infections; Antigens, Viral; Enterovirus; Feces; Genotype; Phylogeny
PubMed: 37169986
DOI: 10.1007/s00705-023-05771-0 -
Poultry Science Jul 2023The epidemic of goose astrovirus (GoAstV) caused huge losses to the poultry industry. Epidemiological studies in China revealed 2 circulating genotypes of GoAstV, but...
The epidemic of goose astrovirus (GoAstV) caused huge losses to the poultry industry. Epidemiological studies in China revealed 2 circulating genotypes of GoAstV, but there is a lack of differential diagnosis tools. By analyzing all published genomes of GoAstV, this study designed specific PCR primers and Taqman probes to recognize different genotypes of GoAstV. After optimization and verification, this study developed a Taqman-based real-time quantitative PCR method that is capable of differential diagnosis. The established qPCR exhibited detection limitations of 100 copies/μL or 10 copies/μL, respectively, for GoAstV genotype 1 and genotype 2, and showed no false positive for other common avian viruses. This method was then used to analyze 72 samples collected from different regions in Jiangxi, and the results were verified by genome sequencing and phylogenetic analysis. These results revealed a complex coinfection of GoAstV different genotypes in China, highlighting the importance of long-term focus on the prevalence and genome evolution of GoAstV.
Topics: Animals; Geese; Phylogeny; Chickens; Avastrovirus; Real-Time Polymerase Chain Reaction; Genotype; Sensitivity and Specificity
PubMed: 37167886
DOI: 10.1016/j.psj.2023.102730 -
Microbiology Spectrum Jun 2023Human astroviruses (HAstVs) are important causative pathogens of acute gastroenteritis (AGE) in children worldwide. MLB and VA HAstVs, which are genetically distinct...
Human astroviruses (HAstVs) are important causative pathogens of acute gastroenteritis (AGE) in children worldwide. MLB and VA HAstVs, which are genetically distinct from the previously known classic HAstVs, have been detected since 2008. To investigate the role of HAstVs in AGE, we conducted molecular detection and characterization of HAstVs circulating in children with AGE in Japan from 2014 to 2021. Out of 2,841 stool samples, HAstVs were detected in 130 (4.6%). MLB1 was the predominant genotype detected (45.4%), followed by HAstV1 (39.2%), MLB2 (7.4%), VA2 (3.1%), HAstV3 (2.3%), HAstV4, HAstV5, and MLB3 (0.8% each). The results demonstrated that HAstV infection in pediatric patients in Japan was dominated by the two major genotypes MLB1 and HAstV1, with a small proportion of other genotypes. The overall infection rates of MLB and VA HAstVs were higher than those of classic HAstVs. The HAstV1 strains detected in this study belonged solely to lineage 1a. The rare MLB3 genotype was detected for the first time in Japan. All three HAstV3 strains belonged to lineage 3c based on the ORF2 nucleotide sequence and were shown to be recombinant strains. HAstVs are one of the pathogens of viral AGE and are considered the third most common viral agents of AGE after rotavirus and norovirus. HAstVs are also suspected to be the causative agents of encephalitis or meningitis in immunocompromised patients and elderly persons. However, little is known about the epidemiology of HAstVs in Japan, especially that of MLBs and VA HAstVs. This study demonstrated epidemiological features and molecular characterization of human astroviruses encompassing a 7-year study period in Japan. This study highlights the genetic diversity of HAstV circulating in pediatric patients with acute AGE in Japan.
Topics: Humans; Child; Aged; Molecular Epidemiology; Japan; Astroviridae Infections; Feces; Phylogeny; Gastroenteritis; Mamastrovirus
PubMed: 37140393
DOI: 10.1128/spectrum.00700-23