| multiplex real-time reverse transcription-polymerase chain reaction for the detection of three viruses associated with poult enteritis complex: turkey astrovirus, turkey coronavirus, and turkey reovirus. | poult enteritis complex (pec) is an economically important disease of young turkeys characterized by diarrhea, poor weight gain, and, in some cases, high mortality. although pec is considered to be a polymicrobial disease, numerous viruses, including turkey coronavirus (tcv), turkey astrovirus type 2 (tastv-2), and avian reoviruses (arvs), have been associated with pec-like disease. real-time reverse transcription-polymerase chain reaction (rrt-pcr), a highly sensitive and specific detection met ... | 2005 | 15839418 |
| detection and molecular characterization of enteric viruses from poult enteritis syndrome in turkeys. | this study was conducted to detect and characterize enteric viruses [rotavirus, turkey astrovirus-2 (tastv-2), reovirus, and turkey coronavirus] from cases of poult enteritis syndrome (pes) in minnesota turkeys. of the intestinal contents collected from 43 pes cases, 25 were positive for rotavirus and 13 for small round viruses by electron microscopy (em). of the enteric virus-positive cases by em (n=27), 16 cases had rotavirus or small round viruses alone and the remaining 11 cases had both vir ... | 2010 | 20075272 |
| identification of chicken enterovirus-like viruses, duck hepatitis virus type 2 and duck hepatitis virus type 3 as astroviruses. | earlier work identified and biologically characterized antigenically distinct enterovirus-like viruses (elvs) of chickens. three of these elvs can now be identified as astroviruses. characterization involved the use of a hitherto undescribed, degenerate primer-based reverse transcription-polymerase chain reaction (rt-pcr) to amplify astrovirus open reading frame (orf) 1b-specific cdna fragments followed by nucleotide sequence determination and analysis of the amplified fragments. elv-1 was confi ... | 2009 | 19156577 |
| the isolation and characterisation of astroviruses from chickens. | the isolation, cultivation and characterization of three chicken astroviruses (castv) isolates are described. they are antigenically related to each other but unrelated to avian nephritis virus (anv) and duck hepatitis virus type 2 (dvh2) in neutralization, immunofluorescence and gel diffusion tests. castv, anv and dvh2 all grew well in the lmh cell line, which was used for assay and serological tests. serological surveys in 1982 and 2001 showed that antibody to castv virus was widespread in bro ... | 2004 | 15223568 |
| enteric viruses detected by molecular methods in commercial chicken and turkey flocks in the united states between 2005 and 2006. | intestinal samples collected from 43 commercial broiler and 33 commercial turkey flocks from all regions of the united states during 2005 and 2006 were examined for the presence of astrovirus, rotavirus, reovirus, and coronavirus by reverse transcription-polymerase chain reaction (pcr), and for the presence of groups 1 and 2 adenovirus by pcr. phylogenetic analysis was performed to further characterize the viruses and to evaluate species association and geographic patterns. astroviruses were ide ... | 2008 | 18646452 |
| avian astroviruses. | as poultry becomes more important in the world economy, it is increasingly important to fully understand the mechanisms of disease and poor production that affect the industry. to more accurately and reasonably treat these diseases, a more sophisticated understanding of interrelatedness is required. this review focuses on avian astroviruses (aastvs), in particular the recent advances in our understanding of aastv molecular biology, and also history, diagnosis, treatment and control. the known aa ... | 2002 | 12396344 |
| high prevalence of turkey parvovirus in turkey flocks from hungary experiencing enteric disease syndromes. | samples collected in 2008 and 2009, from 49 turkey flocks of 6 to 43 days in age and presenting clinical signs of enteric disease and high mortality, were tested by polymerase chain reaction and reverse transcription-polymerase chain reaction for the presence of viruses currently associated with enteric disease (ed) syndromes: astrovirus, reovirus, rotavirus, coronavirus, adenovirus, and parvovirus. turkey astroviruses were found in 83.67% of the cases and turkey astrovirus 2 (tast-2) in 26.53%. ... | 2011 | 22017049 |
| molecular characterization and typing of chicken and turkey astroviruses circulating in the united states: implications for diagnostics. | avian astroviruses were detected by reverse transcriptase and polymerase chain reaction in intestinal contents collected from commercial chickens and turkeys from throughout the united states from 2003 through 2005. astroviruses were detected in birds from both healthy and poorly performing flocks with or without enteric disease. phylogenetic analysis was performed with sequence data from the polymerase (orf-1b) genes of 41 turkey-origin astroviruses and 23 chicken-origin astroviruses. all curre ... | 2006 | 17039840 |
| comparison of capsid gene sequences of turkey astrovirus-2 from poult-enteritis-syndrome-affected and apparently healthy turkeys. | this study was conducted to determine genetic variations in the capsid gene of turkey astrovirus-2 (tastv-2) detected in apparently healthy and poult enteritis syndrome (pes)-affected turkeys. capsid genes of astroviruses obtained from 30 pes-affected and 45 apparently healthy turkey flocks had sequence homologies of 73.4-100% and 72.4-100% at the nucleotide levels, respectively. the analysis of deduced amino acid sequences revealed one amino acid deletion at position 552 in 28 (93.3%) of 30 pes ... | 2011 | 21327787 |
| astroviruses associated with stunting and pre-hatching mortality in duck and goose embryos. | the first detection of avian nephritis virus (anv) in goose embryos and of turkey astrovirus-1 (tastv-1) in duck embryos is described. intestinal samples from duck and goose embryos from five duck and four goose flocks in croatia were tested by polymerase chain reaction for the presence of anv, tastv-1, turkey astrovirus-2, chicken astrovirus, duck astrovirus and also for the presence of avian reovirus, derzsy's disease virus and duck enteritis virus. the kidneys from duck and goose embryos were ... | 2012 | 22845326 |
| astrovirus, reovirus, and rotavirus concomitant infection causes decreased weight gain in broad-breasted white poults. | turkey astrovirus type-2 (tastv-2), turkey rotavirus (trotv), and turkey reovirus (treov) have been implicated as possible causes of enteric diseases and poor production in turkeys; however, numerous studies with each individual virus have failed to reproduce the disease as observed in the field. therefore, in this study we evaluated the pathogenesis of all possible combinations of one, two, or three viruses in comparison to sham inoculates in 3-day-old turkey poults. body weights were recorded ... | 2010 | 20408393 |
| astrovirus-induced synthesis of nitric oxide contributes to virus control during infection. | astrovirus is one of the major causes of infant and childhood diarrhea worldwide. our understanding of astrovirus pathogenesis trails behind our knowledge of its molecular and epidemiologic properties. using a recently developed small-animal model, we investigated the mechanisms by which astrovirus induces diarrhea and the role of both the adaptive and innate immune responses to turkey astrovirus type-2 (tastv-2) infection. astrovirus-infected animals were analyzed for changes in total lymphocyt ... | 2004 | 14722310 |
| molecular characterization of a duck hepatitis virus 3-like astrovirus. | using an orf1b-based astrovirus-specific reverse transcription (rt)-pcr assay, a duck hepatitis virus type 3 (dhv-3)-like astrovirus was detected from four intestinal samples collected from diseased ducks in china. complete genome sequencing and comparative sequence analysis showed that the four duck astrovirus (dastv) isolates were closely related and possessed a typical astrovirus genome organization. genetic analysis of the complete orf2 region revealed that mean amino acid genetic distances ... | 2014 | 24560589 |
| genetic characterization of astroviruses detected in guinea fowl (numida meleagris) reveals a distinct genotype and suggests cross-species transmission between turkey and guinea fowl. | astroviruses can infect mammalian and avian species and are often responsible for gastroenteric disease symptoms. in this study, the complete open reading frame (orf) 2, the 3' end of orf1b and the corresponding intergenic region of astroviruses identified in farmed guinea fowl (numida meleagris) were sequenced and genetically analysed. overall, the genetic sequence of guinea fowl astroviruses was related to turkey astrovirus type 2 (tastv2), although a marked genetic distance was revealed based ... | 2012 | 22527867 |
| a multiplex rt-pcr test for the differential identification of turkey astrovirus type 1, turkey astrovirus type 2, chicken astrovirus, avian nephritis virus, and avian rotavirus. | recent studies have revealed the presence ofastroviruses and rotavirus in numerous poorly performing and healthy chicken and turkey flocks in the united states. the phylogenetic analysis of the sequence data produced during these studies has identified four groups of avian astroviruses circulating in the united states: turkey astrovirus types 1 and 2 (tastv-1 and tastv-2), avian nephritis virus (anv), and a chicken-origin astrovirus (castv). as the molecular epidemiology of poultry enteric disea ... | 2007 | 17992926 |
| antigenic and genomic characterization of turkey enterovirus-like virus (north carolina, 1988 isolate): identification of the virus as turkey astrovirus 2. | a small round virus (srv) was isolated in 1988 from droppings of enteritis-affected turkeys in north carolina and tentatively identified as an enterovirus on the basis of size (18-24 nm in diameter), intracytoplasmic morphogenesis, and a single-stranded rna genome of approximately 7.5 kb. additional characterization studies based on antigenic and genomic analyses were done to determine the relationship of this turkey enterovirus-like virus (telv) to turkey astrovirus 2 (tastv2), a recently chara ... | 2004 | 15077817 |