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Search Results: 1 - 10 of 25 matches for " paramyxovirus "
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Paramyxovirus Fusion and Entry: Multiple Paths to a Common End
Andres Chang,Rebecca E. Dutch
Viruses , 2012, DOI: 10.3390/v4040613
Abstract: The paramyxovirus family contains many common human pathogenic viruses, including measles, mumps, the parainfluenza viruses, respiratory syncytial virus, human metapneumovirus, and the zoonotic henipaviruses, Hendra and Nipah. While the expression of a type 1 fusion protein and a type 2 attachment protein is common to all paramyxoviruses, there is considerable variation in viral attachment, the activation and triggering of the fusion protein, and the process of viral entry. In this review, we discuss recent advances in the understanding of paramyxovirus F protein-mediated membrane fusion, an essential process in viral infectivity. We also review the role of the other surface glycoproteins in receptor binding and viral entry, and the implications for viral infection. Throughout, we concentrate on the commonalities and differences in fusion triggering and viral entry among the members of the family. Finally, we highlight key unanswered questions and how further studies can identify novel targets for the development of therapeutic treatments against these human pathogens.
Breaking In: Human Metapneumovirus Fusion and Entry
Reagan G. Cox,John V. Williams
Viruses , 2013, DOI: 10.3390/v5010192
Abstract: Human metapneumovirus (HMPV) is a leading cause of respiratory infection that causes upper airway and severe lower respiratory tract infections. HMPV infection is initiated by viral surface glycoproteins that attach to cellular receptors and mediate virus membrane fusion with cellular membranes. Most paramyxoviruses use two viral glycoproteins to facilitate virus entry—an attachment protein and a fusion (F) protein. However, membrane fusion for the human paramyxoviruses in the Pneumovirus subfamily, HMPV and respiratory syncytial virus (hRSV), is unique in that the F protein drives fusion in the absence of a separate viral attachment protein. Thus, pneumovirus F proteins can perform the necessary functions for virus entry, i.e., attachment and fusion. In this review, we discuss recent advances in the understanding of how HMPV F mediates both attachment and fusion. We review the requirements for HMPV viral surface glycoproteins during entry and infection, and review the identification of cellular receptors for HMPV F. We also review our current understanding of how HMPV F mediates fusion, concentrating on structural regions of the protein that appear to be critical for membrane fusion activity. Finally, we illuminate key unanswered questions and suggest how further studies can elucidate how this clinically important paramyxovirus fusion protein may have evolved to initiate infection by a unique mechanism.
Viruses Infecting Reptiles
Rachel E. Marschang
Viruses , 2011, DOI: 10.3390/v3112087
Abstract: A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch’s postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions.
Research of Viral Agent in Free-living Pigeon Feces (Columba livia) in the City of S?o Paulo, SP, Brazil, for Transmission Electron Microscopy
Catroxo,M. H. B; Martins,A. M. C. R. P. F; Petrella,S; Curi,N. A; Melo,N.A;
International Journal of Morphology , 2011, DOI: 10.4067/S0717-95022011000200055
Abstract: the pigeon feces are vehicle of diseases both for humans and other animal species. in these birds, the most important viral diseases of the digestive tract are transmitted by the paramyxovirus, adenovirus and coronavirus. avian paramyxoviruses have been isolated from a variety of species of free living and domestic birds worldwide, with several symptoms and clinical signs and economic losses. paramyxoviruses belong to the paramyxoviridae family and avulovirus genus that includes nine serotypes (apmv 1 to 9). avian adenoviruses belong to the adenoviridae family and aviadenovirus genus. in pigeons, cause classical adenovirosis and necrotizing hepatitis. the respiratory and enteric tracts are common targets of coronavirus. they belong to the coronaviridae family and to 3a and 3c groups. in this study, we described the presence of viral agents in free-living pigeon feces (columba livia) from the city of s?o paulo, brazil. the feces were processed by negative staining technique (rapid preparation) for transmission electron microscopy. in this technique paramyxoviruses particles, pleomorphic, roughly spherical or filamentous, measuring 100 to 500 nm of diameter containing an envelope covered by spikes, with characteristic helical herring-bone-like nucleocapsid, measuring 15 to 20 nm in diameter, were visualized in 45 (79%) out of 57 feces samples. in 2 (3.5%) samples, paramyxovirus and adenovirus particles were simultaneously visualized. adenovirus particles were isometric, spherical, characterized as "complete "or" empty ", measuring between 70 and 90 nm in diameter. paramyxovirus and coronavirus particles were detected in 3 (5.2%) samples. coronaviruses were pleomorphic with a diameter of 75-160 nm containing a solar corona-shaped envelope, with projections of approximately 20 nm of diameter. seven (12.3%) samples were negative for viral particles.
Viral Research in Brazilian Owls (Tyto alba and Rhinoptynx clamator) by Transmission Electron Microscopy
Catroxo,M. H. B; Taniguchi,D. L; Melo,N. A; Milanelo,L; Petrella,S; Alves,M; Martins,A. M. C. R. P. F; Rebou?as,M. M;
International Journal of Morphology , 2010, DOI: 10.4067/S0717-95022010000200047
Abstract: the barn-owl (tyto alba) and striped-owl (rhinoptynx clamator) belong respectively to the families tytonidae and strigidae. avian paramyxoviruses have been isolated from a variety of species of wild and domestic birds wordlwide causing diverse clinical symptoms and signs. paramyxoviruses belong to the family paramyxoviridae and avulovirus genus, including nine serotypes (apmv 1 to 9). the lymphoid leukosis is a retrovirus-induced neoplasia. the avian retroviruses belong to the retroviridae family and to the alpharetrovirus genus. coronaviruses can cause respiratory and enteric disease in several species of birds. they belong to the coronaviridae family and to the groups 3a e 3c. in this study, we describe the presence of viruses in four owls, two barn owls (tyto alba) and two striped owls (rhinoptynx clamator), rescued from tree-lined streets of sao paulo, brazil and sent to the recovery center of wild animals of the tietê ecological park, where the animals died. fragments of lung, liver and small intestine of these birds were processed for transmission electron microscopy utilizing negative staining (rapid preparation), immunoelectron microscopy and immunocitochemistry techniques. under the transmission electron microscopy paramyxovirus particles, pleomorphic, roughly spherical or filamentous, measuring 100 to 500 nm of diameter containing an envelope covered by spikes, an herring-bone helical nucleocapsid-like structure, measuring 15 to 20 nm in diameter, were visualized in the samples of lung, liver and small intestine of all owls. in small intestine samples of the two striped-owl (owls 3 and 4) it was detected pleomorphic coronavirus particles with a diameter of 75-160 nm containing a solar corona-shaped envelope, with projections of approximately 20 nm of diameter. in liver fragments of one striped-owl (owl 4) pleomorphic particles of retrovirus with a diameter of 80-145 nm containing an envelope with short projections and diameter of 9 nm were observed. the pr
Pakistan Veterinary Journal , 2009,
Abstract: Serological survey was conducted to detect avian paramyxovirus serotype-2 (APMV-2) antibodies in commercial and backyard bird flocks, using Enzyme-linked immunosorbent assay (ELISA) and haemagglutination inhibition (HI) test. Sera were collected from 212 commercial and 56 backyard birds. Age of commercial birds ranged from one-day old to 62 weeks. In the backyard birds, seroprevalence of APVM-2 was 71.42 and 78.57%, whereas this seroprevalence was 52.35 and 60.84% using the HI test and the ELISA, respectively in commercial poultry birds. No antibodies against APMV-2 were detected in 1-5 days old chicks with either test. The HI test showed the highest positive samples (P<0.05) of APMV-2 in 19-35 days age group (58.33%), followed by age group 11-18 weeks (51.35%) and 25-62 weeks (47.05%). Similarly, ELISA also showed the highest positive samples of APMV-2 (68.75%) in 19-35 days age group (P<0.05), followed by age group 11-18 weeks (62.16%) and 25-62 weeks (56.86%). In conclusion, this study indicated the presence of antibodies to APMV-2 among backyard and commercial poultry birds in Saudi Arabia.
Viruses and virus-like particles identified in ostrich gut contents
H.J. Els,D. Josling
Journal of the South African Veterinary Association , 2012, DOI: 10.4102/jsava.v69i3.821
Abstract: Samples of either gut content from ostriches showing symptoms of enteritis, or allantoic fluid of eggs inoculated with ostrich isolates, were examined for the presence of viral agents by direct negative-contrast electron microscopy. Only a few virus types could be identified with certainty, namely a circovirus (1 sample), a coronavirus (1 sample), a member of either the toga- or bunyaviridae (1 sample), enterovirus (16 samples) and paramyxovirus (26 samples). A large number of samples contained structures resembling myxovirus particles that were interpreted as fringed membranous particles of non-viral origin. An unusual observation of probable single-strand nucleocapsid helices, possibly originating from digested plant material and which were identified in a number of small intestine samples, is reported. This is the 1st report of a spectrum of viruses and virus-like particles occurring in enteric samples from ostriches in South Africa. The low incidence and variety of viruses reported here contribute to the multifactorial origin and complexity of enteric disease in ostriches as well as in other birds and mammalian species.
Journal of Venomous Animals and Toxins , 2002, DOI: 10.1590/S0104-79302002000100013
Abstract: this study reports the isolation of an ophidian paramyxovirus (opmv) in sputum of a captive rattlesnake (crotalus durissus terrificus) kept in a serpentarium located in botucatu, s?o paulo state, brazil. polymerase chain reaction (pcr) and nested-pcr were performed for the identification of the isolated virus.
Isolamento e caracteriza??o biológica da amostra JAP99 do vírus da doen?a de Newcastle isolada de patos domésticos (Neta sp) no Rio de Janeiro
Oliveira Júnior, Jorge Granja de;Schiavo, Paula Amorin;Doretto Júnior, Luciano;Orsi, Maria ?ngela;Mazur, Carlos;Andrade, Cláudio de Moraes;
Ciência Rural , 2005, DOI: 10.1590/S0103-84782005000400035
Abstract: newcastle disease virus (ndv) is the etiological agent of one of the most important diseases of the poultry industry and it has been identified in most of the avian species, wild and domestic birds. in this work, the isolation of the sample denominated jap99 was obtained from duck feces collected in japeri, rj, which was identified by hemagglutination-inhibition technique (hi). the biological characterization of the pathogenicity of the new isolate was investigated at the animal regional laboratory, ministry of agriculture, campinas, sp. by intracerebral inoculation in one day chicks, the index was 1.4. in the intravenous inoculation in birds of six weeks, the index found was 0.0 and the mean death time in chicken embryos was 62 hours. these results pointed out that the isolate jap99 is mesogenic for commercial chickens, offering risk for the poultry industry.
Phylogenetic Analysis of the Nucleoprotein Gene of Newcastle Disease Vaccine Viruses in India
R.N. Ramani Pushpa,J. John Kirubaharan,A. Koteeswaran
International Journal of Poultry Science , 2009,
Abstract: The Nucleoprotein (NP) gene of four different vaccine viruses of NDV commonly used in India namely D58, LaSota, F and K were characterized to find out variations if any. The NP gene was observed to have 1747 nucleotides with a coding sequence of 1470 nucleotides coding for 489 amino acids in all four vaccine viruses irrespective of their virulence to chickens. The variations at the coding sequence were restricted mostly to positions 401-489 and positions between 1 and 400, irrespective of pathogenicity to chickens remain conserved. The epitopes in nucleoprotein gene was also predicted. Among the 20 different epitopes predicted in the NP gene, one epitope with sequence 447FLDLMRA453 was found conserved in all vaccine viruses and was also found to be immunodominant.
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