Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “virus classification”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,135 records · Page 63Linked to original sources
PubMed1987

Isolation of an atypical rotavirus causing diarrhea in neonatal ferrets.

A rotavirus was isolated from neonatal ferrets (Mustela putorius furo) with diarrhea at a large commercial farm. This virus is classified as an atypical rotavirus, probably belonging to the group C rotaviruses. This classification is based on the lack of the rotavirus group A common antigen and on its distinct dsRNA electropherotype pattern in polyacrylamide gels. The diarrheal disease was reproduced experimentally in neonatal ferrets.

Animals↗
PubMed1983

[Cervical condyloma and dysplasia: histological and virological correlation apropos of 100 cases].

Colposcopy and cytology have pointed at the frequency of cervical condylomas with special consideration to flat types. The association condyloma/dysplasia and the behavior of carcinomas in situ as sexually transmitted diseases, suggest that human papillomavirus (H. P. V.) could play a role in cervical cancer. 100 patients have undergone examination for coloscopy, cytology, histology and virology. Dysplastic features were observed in 47 p. 100 and led to classify the lesions in 3 groups according to their importance: condylomas (53 p. 100), dysplastic condylomas (25 p. 100) with predominance of condylomatous pattern, dysplasia (22 p. 100) with a predominant dysplastic pattern. Virologic data were correlated with this classification and demonstrate a dramatic relationship between viral disappearance and the presence of dysplastic features. Virus was found in 83 p. 100 of pure condylomas, 16 p. 100 of dysplastic condylomas and 0 p. 100 of condylomatous dysplasias. Such a phenomenon of viral absence is observed in animal models (malignant transformation of Shope's papilloma): this could be a new argument to suspect the carcinogenic potential of H. P. V. for cervix and external genitalia.

Adolescent↗
PubMed1978

The specificity of neutralizing antibodies to feline leukaemia viruses.

Feline leukaemia viruses (FeLV) of subgroups A (FeLV-A), B(FeLV-B) and C(FeLV-C) were examined by neutralization. The FeLV-A isolates were monotypic. By contrast, there was antigenic variation within subgroups B and C. There was also considerable cross-reactivity between subgroups. Thus, FeLV-A viruses showed weak cross-reactivity to the standard FeLV-C isolate; four of the subgroup B viruses were identical and cross-reactied with the standard FeLV-C, but not with FeLV-A or the fifth FeLV-B, and this latter virus weakly cros-reacted with FeLV-A but not with the FeLV-C; within subgroup C, one virus was indistinguishable from the standard FeLV-C strain but the other two were very similar to FeLV-A. Therefore, subgroup classification based on interference did not altogether correspond with neutralizing behaviour for subgroups B and C.

Animals↗
PubMed2006

High throughput sequencing and comparative genomics of foot-and-mouth disease virus.

Despite a basic understanding of many aspects of FMD biology, much information regarding FMDV virulence, host range, and virus transmission remains poorly understood. Here we present how the use of high throughput sequencing for complete genome sequences of foot-and mouth disease virus (FMDV) led to a series of new insights into viral genome sequence conservation and variability, genetic diversity in nature and phylogenetic classification of isolates, including the first complete sequences of the South African Territories type 1 and 3 (SAT1 and SAT3) genomes. Comparative genomic analysis of full-length sequences of FMDV isolates did allow: (i) the identification of highly conserved regulatory or coding regions which are critical for aspects of virus biology as well as novel viral genomic motifs with likely biological relevance; (ii) characterization of the first complete sequences of the SAT1 and SAT3 genomes; (iii) identification of a novel SAT virus lineage genetically distinct from other SAT and Euro-Asiatic lineages; (iv) precise identification of strains circulating around the world for epidemiological and forensic attribution; (v) assessment of mutation and recombination processes as mechanisms equally involved in evolution; (vi) mutation rates, tolerance and constraints of genes and proteins during evolution of FMD viruses during in vivo replication and (vi) support for the hypothesis of a new evolutionary model.

Animals↗
PubMedDate not supplied

Twenty years of progress and beckoning frontiers in cardiovascular pathology: cardiomyopathies.

In the last 20 years, with the advent of cardiac transplantation and the availability of molecular biology techniques, major advancements were achieved in the understanding of cardiomyopathies. Novel cardiomyopathies have been discovered (arrhythmogenic right ventricular, primary restrictive, and noncompacted myocardium) and added in the update of WHO classification. Myocarditis was also included with the name "inflammatory cardiomyopathy." Adenoviruses and parvoviruses were found to be frequent cardiotropic viruses in addition to enteroviruses. The extraordinary progress accomplished in molecular genetics of inherited cardiomyopathies allowed to establish hypertrophic and restrictive cardiomyopathies as sarcomeric ("force generation") diseases, dilated cardiomyopathies as cytoskeleton ("force transmission") disease, and arrhythmogenic right ventricular cardiomyopathy (ARVC) as cell junction disease. If we consider also cardiomyopathy as ion channel disease (long and short QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia), because they are diseases of the myocardium associated with electrical dysfunction, then a genomic/postgenomic classification of inherited cardiomyopathies may be put forward: cytoskeletal cardiomyopathy, sarcomeric cardiomyopathy, cell junction cardiomyopathy and ion channel cardiomyopathy.

Adenovirus Infections, Human↗
PubMed2026

Longitudinal whole-genome analysis of bluetongue virus identifies conserved serotype-specific genomes and distinct genomic constellations within a Colorado sheep flock (2021-2023).

Bluetongue virus (BTV) is a segmented double-stranded RNA virus of ruminants transmitted by Culicoides spp. biting midges. Although the genome consists of ten segments, classification into serotypes is primarily based on genome segment 2. However, reassortment among genomic segments is a major driver of BTV evolution and diversity. This study used longitudinal whole-genome sequencing to characterize BTV genomes collected from 2021 to 2023 within a single sheep flock in Colorado, where multiple serotypes co-circulate. Whole-genome sequences were generated from fourteen blood samples representing four serotypes: BTV-6, -11, -13, and -17. Longitudinal sampling identified multiple BTV serotypes within individual sheep across consecutive years. Tanglegram analysis comparing segment phylogenies to the segment 2 tree demonstrated incongruent topologies across all genomic segments, suggestive of reassortment or the circulation of distinct genomic constellations. Nucleotide-level comparisons revealed high sequence homology among same-serotype samples from the same year, while the greatest genetic divergence was observed among BTV-17 genomes collected in different years. Additionally, all BTV-13 genomes contained a previously undescribed nonsynonymous substitution in segment 10 predicted to extend the encoded protein by three amino acids. Together, these findings demonstrate that highly conserved BTV genomes and distinct genomic constellations can be detected at the flock level across multiple years. This longitudinal whole-genome approach reveals the genetic complexity of endemic BTV populations, including novel variants and genomic patterns consistent with reassortment that are lost with conventional serotyped-based approaches, highlighting the need to integrate whole-genome characterization into endemic BTV monitoring programs.

Animals↗
PubMed1992

Potyviruses, monoclonal antibodies, and antigenic sites.

Virus-specific and cross-reactive monoclonal antibodies have been produced to at least 19 different aphid-transmitted potyviruses. This report summarizes the development of these monoclonal antibodies as well as presents information on the delineation of the virus-specific and group-common epitopes defined by these monoclonal antibodies. Virus-specific and group-common antigenic determinants were mapped by a variety of techniques, including analysis of antigen: antibody reactivity patterns, determination of N-terminal vs. trypsin-resistant core peptide-specificity, immunoanalysis of overlapping synthetic peptides, and immunoanalysis of bacterially expressed coat-protein gene products. Of those monoclonal antibodies that have been examined, monoclonal antibody-defined virus-specific epitopes are virion surface-located within the 30+ amino acid amino terminus, whereas the group-common epitopes are found in the trypsin-resistant core protein not usually located on the virion surface, as has been shown previously with certain polyclonal antibodies. New information is presented on the analysis of bean yellow mosaic virus amino terminal epitopes as well as on the identification of amino terminal antigenic determinants shared between strains of bean yellow mosaic virus and pepper mottle virus. A recommendation on the evaluation and use of a panel of potyvirus broad-spectrum reacting monoclonals as reference monoclonal antibodies for the detection and classification of aphid-transmitted potyviruses is also presented.

Amino Acid Sequence↗
PubMed1995

Sequence comparison and classification of beet luteovirus isolates.

Three distinct sequence groups were found among partial nucleotide sequences of 38 isolates of beet western yellows virus (BWYV) and beet mild yellowing virus (BMYV) from Europe, Iran and the USA. The first group contains both sugar beet and oilseed rape specific isolates, and the differentiating characteristic linked to this host range specificity are 2 single base pair changes in a 1,200 nucleotide region of the genome. It is proposed that the European BWYV strains that can be transferred at low frequency between rape and sugar beet belong to this group. Also belonging to this group are the published BWYV sequences of Veidt et al. and of the California BWYV-ST9 isolate. The second group contains mostly rape-derived isolates which have an intergenic region highly distinct from that of group-1 isolates but similar polymerase and coat protein regions. It is proposed that the rape-specific BWYV isolates which cannot be transmitted to sugar beet belong to this group. The third group contains mostly beet-specific isolates from Southern Europe and Iran, and may be adapted to the Mediterranean climate and flora. It is distinct from groups 1 and 2 in all three genome regions investigated and its polymerase and intergenic regions are as much related to those of potato leafroll virus (PLRV) and curcurbit aphid borne yellows virus (CABYV) as they are to those of group-1 and group-2. On the basis of sequence similarities and established nomenclature it is proposed to use BWYV for groups 1 and 2 (BWYV-1 and BWYV-2 respectively) and to use BMYV for group-3 isolates, which are distinct enough from the other two groups to merit a separate nomenclature.

Amino Acid Sequence↗
PubMed2002

Role of the human papilloma virus in the development of cervical intraepithelial neoplasia and malignancy.

Human papilloma virus (HPV) is a public health problem as a sexually transmitted disease and as a critical factor in the pathogenesis of various cancers. The clinical manifestations, epidemiology, and virology that are critical to understanding the process of cervical dysplasia and neoplasia are reviewed. A discussion of the cervical transformation zone and the classification of cervical dysplasia and neoplasia leads into the importance of the Papanicolaou smear in prevention of potentially devastating sequelae of this virus. The role of the immune system in the progression of the disease and how it relates to vaccines, as well as treatment and prevention of HPV, are reviewed.

Female↗
PubMed1997

Relation between phylogeny of African green monkey CD4 genes and their respective simian immunodeficiency virus genes.

An apparent species-specific relatedness of SIVagm suggests a coevolution with their natural hosts. However, the exact species or subspecies classification of African green monkeys, AGM, is uncertain because current classification schemes rely on phenotype markers, while more definitive genetic data are lacking. In this study, the CD4 protein involved in tissue type recognition was genetically cloned and sequenced from PBMC RNA from all AGM species, including Barbados green monkeys (BGM). Phylogenetic trees were constructed that also included genomic CD4 nucleotide sequences from patas, sooty mangabeys, rhesus and pig-tail macaques, chimpanzees, and humans. Chimpanzees and humans consistently clustered together. Monkeys within the Cercopithecus genus formed a separate cluster which included pata monkeys, supporting its grouping as a member of Cercopithecus. Surprisingly, sooty mangabeys were genetically more closely related to Asian macaques than to other African species, which might explain why macaques are more susceptible to infection by the SIVsm group than to infection by SIVagm or HIV-1 and why patas, on the other hand, are highly susceptible to SIVagm infection. Based on CD4 genetic data, tantalus, vervets, grivets, and sabaeus formed separate subgroups with BGM grouping closely with vervets. The branching order of the AGM species was related to that of their respective SIVagm env sequences. The study suggests a strong correlation between CD4 phylogeny and the susceptibility of the host species to infection by a specific lentivirus and supports the assumption of a coevolution of SIVagm and AGM. CD4 sequencing is suggested as a relevant method for genetic determination of primate species.

Amino Acid Sequence↗
PubMedDate not supplied

Development of a diploid cell line from fetal calf lung for virus vaccine production.

Details of isolation and replication of a fetal calf diploid cell (FCDC) is given. From the karyological point of view, the fairly large number of chromosomes existing in metaphase spreads made counting rather tedious. Lack of practical classification was another problem which made reference to individual chromosomes difficult. By increasing the population doubling of this cell, a tendency of telocentric chromosomes to undergo centric fusion was observed. Susceptibility of FCDC to different viruses is described.

Animals↗
PubMedDate not supplied

Serotyping of avian infectious bronchitis viruses by the virus-neutralization test.

The antigenic relationships of 12 strains of infectious bronchitis virus (IBV) were evaluated by a virus-neutralization procedure similar to that used in typing human rhinoviruses. Such a procedure consists of reciprocal neutralization tests performed by reacting 32-320 EID50 or plaque-forming units of virus with 20 antibody units of antiserum. Eight serologic groups were identified by chicken embryo assay, and 4 by plaque-reduction (90%). In general, serologic groupings were not distinct but reflected numerous intergroup relationships. The contrasting results exhibited by indicator systems are viewed as differences in the accuracy of the methods employed. It is suggested that before an IBV classification scheme can be proposed, agreement must be reached on the most suitable indicator system, techniques must be standardized, and reference viruses and antisera distributed to several institutions for comparison testing. In addition, cross-protection studies are needed to determine the importance of IBV serotypes and/or variants on vaccine efficacy.

Animals↗
PubMedDate not supplied

Chronic venous insufficiency in HIV-positive persons with and without a history of injection drug use.

OBJECTIVE: To examine chronic venous insufficiency in human immunodeficiency virus-positive persons with and without a history of injection drug use and to examine the extent to which neuropathy further increased the risk of chronic venous insufficiency. DESIGN: Cross-sectional stratified design with quota sampling. SETTING: Infectious diseases clinic in a large, urban midwestern city. PARTICIPANTS: Human immunodeficiency virus-positive persons, 27 with no history of injection drug use and 46 with a history of injection drug use, who met the inclusion criteria, including being 30 to 65 years of age, not pregnant, and willing to respond to a questionnaire and have their lower legs examined, were enrolled until the quota for each stratum (no injection drug use and injection drug use) was filled. MAIN OUTCOME MEASURES: Chronic venous insufficiency clinical classification, injection drug use history, and presence of peripheral neuropathy. MAIN RESULTS: Sixty-one percent of injection drug users (28/46) presented with severe chronic venous insufficiency compared with 11% (3/27) of noninjection drug users (P< .001). The presence of lower extremity neuropathy was not significantly related to chronic venous insufficiency classification. CONCLUSIONS: This is the first study to report the high risk of chronic venous insufficiency in human immunodeficiency virus-infected persons who inject drugs. Chronic venous insufficiency should be assessed in human immunodeficiency virus-positive persons when there is a history of injection drug use, and measures to protect the legs should be implemented.

Adult↗
PubMed2003

Bacterial diversity in shallow oligotrophic marine benthos and overlying waters: effects of virus infection, containment, and nutrient enrichment.

Little is known of the factors shaping sediment bacterial communities, despite their high abundance and reports of high diversity. Two factors hypothesized to shape bacterial communities in the water column are nutrient (resource) availability and virus infection. The role these factors play in benthic bacterial diversity was assessed in oligotrophic carbonate-based sediments of Florida Bay (USA). Sediment-water mesocosm enclosures were made from 1-m diameter clear polycarbonate cylinders which were pushed into sediments to approximately 201 cm sediment depth enclosing approximately 80 L of water. Mesocosms were amended each day for 14 d with 10 microM NH4+ and 1 microM PO4(3-). In a second experiment, viruses from a benthic flocculent layer were concentrated and added back to flocculent layer samples which were collected near the mesocosm enclosures. Photosynthesis by microalgae in virus-amended incubations was monitored by pulse-amplitude modulated (PAM) fluorescence. In both experiments, bacterial diversity was estimated using automated rRNA intergenic spacer analysis (ARISA), a high-resolution fingerprinting approach. Initial sediment bacterial operational taxonomic unit (OTU) richness (236 +/- 3) was higher than in the water column (148 +/- 9), where an OTU was detectable when its amplified DNA represented >0.09% of the total amplified DNA. Effects on bacterial diversity and operational taxonomic unit (OTU) richness in nutrient-amended mesocosms may have been masked by the effects of containment, which stimulated OTU richness in the water column, but depressed OTU richness and diversity in sediments. Nutrient addition significantly elevated virus abundance and the ratio of viruses to bacteria (p < 0.05 for both) in the sediments, concomitant with elevated bacterial diversity. However, water column bacterial diversity (in unamended controls) was not affected by nutrient amendments, which may be due to rapid nutrient uptake by sediment organisms or adsorption of P to carbonate sediments. Addition of live viruses to benthic flocculent layer samples increased bacterial OTU diversity and richness compared with heat-killed controls; however, cluster analyses showed that the community structure in the virus-amended mesocosms varied greatly between replicates. Despite the strong effects upon eubacterial communities, photosynthesis of co-occurring protists and cyanobacteria was not significantly altered by the presence of virus concentrates. This study supports the hypothesis that nutrient availability plays a key role in shaping sediment bacterial communities, and also that viruses may regulate the abundance of the dominant competitors and allow less dominant organisms to maintain or increase their abundance in a community due to decreased competition for resources.

Bacteria↗
PubMed1980

Eastern equine encephalomyelitis in Panama: the epidemiology of the 1973 epizootic.

In late June 1973, a small outbreak of equine encephalitis caused by eastern equine encephalomyelitis (EEE) virus occurred in the Republic of Panama. At least 100 horses were affected by the disease and 40 died. More than 1,700 human sera were obtained from areas of virus activity but no serological evidence for infection was found. Four isolates of EEE virus were recovered, one of which was from a small pool of Culex taeniopus mosquitoes. Serologic studies of infected horses and classification by the short incubation hemagglutination-inhibition tests revealed that these isolates were South American strains. Our evidence suggests that another agent virulent for horses was active during this outbreak.

Animals↗