Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017160 (gastroenteritis)
 11,398 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Canine parvovirus 2 (CPV-2) is one of the most important viruses that causes haemorrhagic gastroenteritis and myocarditis of dogs worldwide. The picture has been complicated further due to the emergence of new mutants of CPV, namely: CPV-2a, CPV-2b and CPV-2c. In this study, the molecular characterisation of strains present in the CPV vaccines available on the Indian market was performed using polymerase chain reaction and DNA sequencing. The VP1/VP2 genes of two vaccine strains and a field strain (Bhopal) were sequenced and the nucleotide and the deduced amino acid sequences were compared. The results indicated that the isolate belonged to CPV type 2b and the strains in the vaccines belonged to type CPV-2. From the study, it is inferred that the CPV strain used in commercially available vaccine preparation differed from the strains present in CPV infection in dogs in India.
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PMID:Molecular characterisation and nucleotide sequence analysis of canine parvovirus strains in vaccines in India. 2039 69

The human pathogen, group A rotavirus, is the most prevalent cause of acute infantile and pediatric gastroenteritis worldwide, especially in developing countries. There is an urgent demand for safer, more effective and cheaper vaccines against rotavirus infection. Plant-derived antigens may provide an exclusive way to produce economical subunit vaccines. Virus-like particles, constituting viral capsid proteins without viral nucleic acids, are considered a far safer candidate compared with live attenuated viral vaccines. In this study, the rotavirus capsid proteins VP2, VP6 and VP7 were co-expressed in transgenic tobacco plants, and their expression levels, formation of rotavirus-like particles (RV VLPs) and immunogenicity were extensively studied. Quantitative real-time RT-PCR and Western blot analysis revealed that the expression level of vp6 was the highest while vp7 was expressed at the lowest levels. The RV VLPs were purified from transgenic tobacco plants and analyzed by electron microscopy and Western blot. Results indicated that the plant-derived VP2, VP6 and VP7 proteins self-assembled into 2/6 or 2/6/7 RV VLPs with a diameter of 60-80 nm. When orally delivered into mice with cholera toxin as an adjuvant, the total soluble protein extracted from transgenic tobacco plants induced rotavirus-specific antibodies comparable with those of attenuated rotavirus vaccines, while VP 2/6/7 induced higher serum IgG and fecal IgA titers compared with VP 2/6.
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PMID:Immunogenicity and virus-like particle formation of rotavirus capsid proteins produced in transgenic plants. 2110 33

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.
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PMID:Human bocavirus infection in children with acute gastroenteritis in Japan and Thailand. 2118 24

A case of canine parvovirus type 2c (CPV-2c) infection in a 3-month-old feral kitten with a cerebral abscess and neurological disease is reported. The cat displayed ataxia and convulsions together with signs of gastroenteritis and profound alteration of the total and differential white blood cell counts. A parvovirus strain was detected by a TaqMan assay in the blood and faeces of the affected kitten, which was characterised as CPV by means of molecular assays but did not react with any of the CPV type-specific probes. By sequence and phylogenetic analyses of the VP2-protein gene, the CPV-2c strain displayed a non-coding mutation in the probe-binding region. Although the role of CPV-2c in this particular case is unclear, it is possible that it predisposed the kitten to the clinical signs seen. Continuous surveillance is needed to monitor future spreading of this CPV-2c mutant, and any associated clinical signs, in the dog and cat population.
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PMID:Canine parvovirus type 2c infection in a kitten associated with intracranial abscess and convulsions. 2120 17

Group A human rotaviruses (RVs) remain the most frequently detected viral agents associated with acute gastroenteritis in infants and young children. Despite their medical importance, relatively few complete genome sequences have been determined for commonly circulating G/P-type strains (i.e., G1P[8], G2P[4], G3P[8], G4P[8], and G9P[8]). In the current study, we sequenced the genomes of 11 G4P[8] isolates from stool specimens that were collected in Washington, DC during the years of 1974-1991. We found that the VP7-VP4-VP6-VP1-VP2-VP3-NSP1-NSP2-NSP3-NSP4-NSP5/6-encoding genes of all 11 G4P[8] RVs have the genotypes of G4-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. By constructing phylogenetic trees for each gene, extensive intra-genotypic diversity was revealed among the G4P[8] RVs, and new sub-genotype gene alleles were identified. Several of these alleles are nearly identical to those of G3P[8] isolates previously sequenced from this same Washington, DC collection, strongly suggesting that the RVs underwent gene reassortment. On the other hand, we observed that some G4P[8] RVs exhibit completely different allele-based genome constellations, despite being collected during the same epidemic season; there was no evidence of gene reassortment between these strains. This observation extends our previous findings and supports the notion that stable, genetically-distinct clades of human RVs with the same G/P-type can co-circulate in a community. Interestingly, the sub-genotype gene alleles found in some of the DC RVs share a close evolutionary relationship with genes of more contemporary human strains. Thus, archival human RVs sequenced in this study might represent evolutionary precursors to modern-day strains.
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PMID:Intra-genotypic diversity of archival G4P[8] human rotaviruses from Washington, DC. 2171 2

Detection and characterisation of the canine parvovirus (CPV-2) strains that are currently circulating are essential for the understanding of viral evolution and the development of measures to control its spread. In the present study, stool samples from 144 dogs were analysed by polymerase chain reaction (PCR) for CPV-2, and 29.2% (42/144) of them were positive. From the 42 positive strains, 71.4% (30) of the dogs had signs of haemorrhagic gastroenteritis. The sequencing of the 583 bp fragment of the VP2 gene from the positive strains identified 78.6% (33/42) of them as type 2c, 19% (8/42) as type 2b and 2.4% (1/42) as type 2a. A phylogenetic analysis of the variants circulating in the canine population of Brazil showed that they are very similar to those found in other countries and type 2c has become the predominant type circulating in Brazil.
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PMID:Typing of canine parvovirus strains circulating in Brazil between 2008 and 2010. 2228 Aug 82

Human noroviruses (HuNoV) are a major cause of viral gastroenteritis worldwide, yet, due to the inability to propagate HuNoV in cell culture, murine norovirus (MNV) is typically used as a surrogate to study norovirus biology. MNV-3 represents an attractive strain to study norovirus infections in vivo because it establishes persistence in wild-type mice, yet causes symptoms resembling gastroenteritis in immune-compromised STAT1(-/-) mice. The lack of reverse-genetics approaches to recover genetically defined MNV-3 has limited further studies on the identification of viral sequences that contribute to persistence. Here we report the establishment of a combined DNA-based reverse-genetics and mouse-model system to study persistent MNV-3 infections in wild-type (C57BL/6) mice. Viral RNA and infectious virus were detected in faeces for at least 56 days after inoculation. Strikingly, the highest concentrations of viral RNA during persistence were detected in the caecum and colon, suggesting that viral persistence is maintained in these tissues. Possible adaptive changes arising during persistence in vivo appeared to accumulate in the minor capsid protein (VP2) and the viral polymerase (NS7), in contrast with adaptive mutations selected during cell-culture passages in RAW264.7 cells that appeared in the major capsid protein (VP1) and non-structural protein NS4. This system provides an attractive model that can be readily used to identify viral sequences that contribute to persistence in an immunocompetent host and to more acute infection in an immunocompromised host, providing new insights into the biology of norovirus infections.
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PMID:Development of a reverse-genetics system for murine norovirus 3: long-term persistence occurs in the caecum and colon. 2249 35

Group A rotaviruses (RVs) are 11-segmented, double-stranded RNA viruses and are primary causes of gastroenteritis in young children. Despite their medical relevance, the genetic diversity of modern human RVs is poorly understood, and the impact of vaccine use on circulating strains remains unknown. In this study, we report the complete genome sequence analysis of 58 RVs isolated from children with severe diarrhea and/or vomiting at Vanderbilt University Medical Center (VUMC) in Nashville, TN, during the years spanning community vaccine implementation (2005 to 2009). The RVs analyzed include 36 G1P[8], 18 G3P[8], and 4 G12P[8] Wa-like genogroup 1 strains with VP6-VP1-VP2-VP3-NSP1-NSP2-NSP3-NSP4-NSP5/6 genotype constellations of I1-R1-C1-M1-A1-N1-T1-E1-H1. By constructing phylogenetic trees, we identified 2 to 5 subgenotype alleles for each gene. The results show evidence of intragenogroup gene reassortment among the cocirculating strains. However, several isolates from different seasons maintained identical allele constellations, consistent with the notion that certain RV clades persisted in the community. By comparing the genes of VUMC RVs to those of other archival and contemporary RV strains for which sequences are available, we defined phylogenetic lineages and verified that the diversity of the strains analyzed in this study reflects that seen in other regions of the world. Importantly, the VP4 and VP7 proteins encoded by VUMC RVs and other contemporary strains show amino acid changes in or near neutralization domains, which might reflect antigenic drift of the virus. Thus, this large-scale, comparative genomic study of modern human RVs provides significant insight into how this pathogen evolves during its spread in the community.
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PMID:Diversity and relationships of cocirculating modern human rotaviruses revealed using large-scale comparative genomics. 2269 51

Group A rotaviruses (RVA) are a major cause of acute infantile gastroenteritis. The viral genome comprises 11 double-stranded RNA segments and the respective gene segments are classified into more than eight genotypes, according to the nucleotide sequence similarities. So far, it has been difficult to amplify full-length sequences of long RNA segments of rotaviruses by one-time only RT-PCR (especially in the genes for the viral proteins VP1, VP2, VP3 and VP4). In this study, a set of universal primers to amplify all 11 segments of RVA was designed by aligning the nucleotide sequences of the typical rotavirus strains. Using these primers and a high-fidelity and rapid DNA polymerase in a one-step reverse transcription polymerase chain reaction, almost the entire length of all 11 segments of the seven rotavirus strains Wa, DS-1, Hochi, 69M, WI61, M37 and SA11-S1 were accurately and rapidly amplified. In addition, all 11 segments of rotavirus obtained from a fecal specimen were successfully amplified. In conclusion, the method described here will be useful as an RVA detection system and protocol for complete analysis of the 11 genome sequences.
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PMID:Amplification of all 11 RNA segments of group A rotaviruses based on reverse transcription polymerase chain reaction. 2270 35

Human noroviruses are responsible for most cases of human gastroenteritis (GE) worldwide and are recurrent problem in environments where close person-to-person contact cannot be avoided (1, 2). During the last few years an increase in the incidence of outbreaks in hospitals has been reported, causing significant disruptions to their operational capacity as well as large economic losses. The identification of new antiviral approaches has been limited due to the inability of human noroviruses to complete a productive infection in cell culture (3). The recent isolation of a murine norovirus (MNV), closely related to human norovirus (4) but which can be propagated in cells (5) has opened new avenues for the investigation of these pathogens (6, 7). MNV replication results in the synthesis of new positive sense genomic and subgenomic RNA molecules, the latter of which corresponds to the last third of the viral genome (Figure 1). MNV contains four different open reading frames (ORFs), of which ORF1 occupies most of the genome and encodes seven non-structural proteins (NS1-7) released from a polyprotein precursor. ORF2 and ORF3 are contained within the subgenomic RNA region and encode the capsid proteins (VP1 and VP2, respectively) (Figure 1). Recently, we have identified that additional ORF4 overlapping ORF2 but in a different reading frame is functional and encodes for a mitochondrial localised virulence factor (VF1) (8). Replication for positive sense RNA viruses, including noroviruses, takes place in the cytoplasm resulting in the synthesis of new uncapped RNA genomes. To promote viral translation, viruses exploit different strategies aimed at recruiting the cellular protein synthesis machinery (9-11). Interestingly, norovirus translation is driven by the multifunctional viral protein-primer VPg covalently linked to the 5' end of both genomic and subgenomic RNAs (12-14). This sophisticated mechanism of translation is likely to be a major factor in the limited efficiency of viral recovery by conventional reverse genetics approaches. Here we report two different strategies based on the generation of murine norovirus-1 (referred to as MNV herewith) transcripts capped at the 5' end. One of the methods involves both in vitro synthesis and capping of viral RNA, whereas the second approach entails the transcription of MNV cDNA in cells expressing T7 RNA polymerase. The availability of these reverse genetics systems for the study of MNV and a small animal model has provided an unprecedented ability to dissect the role of viral sequences in replication and pathogenesis (15-17).
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PMID:Reverse genetics mediated recovery of infectious murine norovirus. 2276 Apr 50


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