| development and optimization of a direct plaque assay for human and avian metapneumoviruses. | the genus metapneumovirus within the subfamily pneumovirinae and family paramyxoviridae includes only two viruses, human metapneumovirus (hmpv) and avian metapneumovirus (ampv), which cause respiratory disease in humans and birds, respectively. these two viruses grow poorly in cell culture and other quantitation methods, such as indirect immuno-staining and immuno-fluorescent assays, are expensive, time consuming, and do not allow for plaque purification of the virus. in order to enhance researc ... | 2012 | 22684013 |
| avian metapneumovirus circulation in italian broiler farms. | with increasing frequency, avian metapneumovirus (ampv) is reported to induce respiratory signs in chickens. an adequate knowledge of current ampv prevalence among italian broilers is lacking, with little information available on its economical and health impact on the poultry industry. in order to collect preliminary data on the epidemiological context of ampv in broiler flocks, a survey was performed in areas of northern italy with high poultry density from 2014 to 2016. upper respiratory trac ... | 2018 | 29253264 |
| avian metapneumovirus subtype c in wild waterfowl in ontario, canada. | avian metapneumovirus (ampv) is an emerging poultry pathogen that has a significant economic impact on poultry production worldwide. the geographic range of the virus continues to expand, and wild birds have been implicated as reservoirs of ampv that have the potential to spread the virus over long distances. our objective was to determine the apparent prevalence of ampv subtype c in wild waterfowl in ontario, canada. wild waterfowl were captured in august and september, 2016 as part of routine ... | 2018 | 29457370 |
| avian metapneumovirus subtype b around europe: a phylodynamic reconstruction. | avian metapneumovirus (ampv) has been recognized as a respiratory pathogen of turkey and chickens for a long time. recently, a crescent awareness of ampv, especially subtype b, clinical and economic impact has risen among european researchers and veterinarians. nevertheless, the knowledge of its epidemiology and evolution is still limited. in the present study, the broadest available collection of partial g gene sequences obtained from european ampv-b strains was analyzed using different phylody ... | 2020 | 32641149 |
| biochemical characterization of the small hydrophobic protein of avian metapneumovirus. | avian metapneumovirus (ampv) is a paramyxovirus that has three membrane proteins (g, f, and sh). among them, the sh protein is a small type ii integral membrane protein that is incorporated into virions and is only present in certain paramyxoviruses. in the present study, we show that the ampv sh protein is modified by n-linked glycans and can be released into the extracellular environment. furthermore, we demonstrate that glycosylated ampv sh proteins form homodimers through cysteine-mediated d ... | 2012 | 22659296 |
| the characterization of monoclonal antibodies to human metapneumovirus and the detection of multiple forms of the virus nucleoprotein and phosphoprotein. | little is known of the proteome of human metapneumovirus (hmpv). in this study a panel of monoclonal antibodies to the virus have been characterized and used to identify viral proteins present in infected cell lysates. of thirteen anti-hmpv monoclonal antibodies four reacted with recombinant fusion glycoprotein and one with recombinant g glycoprotein by immunofuorescence but not in western blots suggesting that they recognize conformation dependent epitopes. the specificity of the remaining anti ... | 2012 | 22585723 |
| a family-wide rt-pcr assay for detection of paramyxoviruses and application to a large-scale surveillance study. | family-wide molecular diagnostic assays are valuable tools for initial identification of viruses during outbreaks and to limit costs of surveillance studies. recent discoveries of paramyxoviruses have called for such assay that is able to detect all known and unknown paramyxoviruses in one round of pcr amplification. we have developed a rt-pcr assay consisting of a single degenerate primer set, able to detect all members of the paramyxoviridae family including all virus genera within the subfami ... | 2012 | 22496880 |
| molecular characterization of brazilian avian pneumovirus isolates using reverse transcription-polymerase chain reaction, restriction endonuclease analysis and sequencing of a g gene fragment. | a reverse transcriptase-polymerase chain reaction (rt-pcr) assay was employed to amplify a g gene transcript of the avian pneumovirus (apv) in two european turkey isolates and two brazilian chicken isolates. the pcr products were digested using restriction endonucleases and the restriction patterns were compared with earlier reported isolate patterns. the same pcr products were cloned into puc18 and sequenced. restriction patterns and sequence analyses of the approximately 600 bp products from b ... | 1999 | 26911601 |
| dual infection of turkey poults with avian pneumovirus and mycoplasma synoviae. | poults were infected with avian pneumovirus (apv) at 1-day-old, followed by mycoplasma synoviae (ms) 3 days later. dual infection did not cause an increase in severity of clinical disease, or gross and microscopic lesions due to apv. the patterns of virus and ms isolations from tracheal swabs or tissues from single and dual infected groups were similar. ms infection did not induce ms antibodies, nor did it affect seroconversion to apv in the dual infection. | 1999 | 26905498 |
| research note: detection of avian metapneumovirus subgroup c specific antibodies in a mallard flock in italy. | avian metapneumovirus (ampv) is a viral pathogen that causes respiratory signs and drops in egg production most notably in turkeys but also affects chickens, ducks and other species. four subgroups (ampv-a, -b, -c and -d) have been characterized to date, which differ genetically, antigenically and in terms of geographic distribution and host range. despite the rising awareness towards ampv, many aspects of its epidemiology are still poorly understood. in this pilot study, a serological survey wa ... | 2021 | 34089934 |
| in vitro and in vivo studies on the pathogenicity of avian pneumovirus for the chicken oviduct. | the pathogenicity of avian pneumovirus (apv) for the chicken oviduct was studied in vitro using oviduct organ cultures (ooc), in vivo in young chicks with artificially enlarged oviducts and in adult female chickens. the oocs were prepared from artificially enlarged oviducts of young chicks induced by oestrogen treatment and from normal oviducts of adult hens. the pathogenicity of apv for oocs in vitro and oviducts in vivo were assessed by virus titrations and immunofluorescence. while in vitro e ... | 1999 | 26915381 |
| comparative pathogenesis of a subtype a with a subtype b avian pneumovirus in turkeys. | this paper describes a study in which the pathogenesis of avian pneumovirus strains, isolated in belgium, and belonging to the two subtypes a and b, were compared in 2-week-old turkeys. after oculonasal inoculation, animals were either observed for clinical signs or killed for pathological and virological examination. virus titration and immunofluorescence were performed on the conjunctivae, turbinates, sinuses, upper and lower part of the trachea, lungs and air sacs. no differences were seen be ... | 1999 | 26915379 |
| detection and subtyping avian metapneumovirus from turkeys in iran. | avian metapneumovirus (ampv) causes diseases like rhinotracheitis in turkeys, swollen head syndrome in chickens and avian rhinotracheitis in other birds. causing respiratory problems, ampv adversely affects production and inflicts immense economic losses and mortalities, especially in turkey flocks. in recent years, several serological and molecular studies have been conducted on this virus, especially in poultry in asia and iran. the purpose of the present study was detecting and subtyping ampv ... | 2017 | 28785384 |
| complete genome sequence of an avian metapneumovirus subtype a strain isolated from chicken (gallus gallus) in brazil. | we report here the complete genome sequence of an avian metapneumovirus (ampv) isolated from a tracheal tissue sample of a commercial layer flock. the complete genome sequence of ampv-a/chicken/brazil-sp/669/2003 was obtained using miseq (illumina, inc.) sequencing. phylogenetic analysis of the complete genome classified the isolate as avian metapneumovirus subtype a. | 2017 | 28729279 |
| first report of avian metapneumovirus subtype b field strain in a romanian broiler flock during an outbreak of respiratory disease. | avian metapneumovirus (ampv) represents one of the most prevalent diseases of turkey, especially in combination with other pathogens, and its frequency is also increasing among chickens. despite this evidence, epidemiologic data are poor and scattered, severely preventing control of the disease even in highly developed areas such as europe. in the present study, the detection and characterization of an ampv subtype b strain circulating in a vaccinated but symptomatic romanian broiler flock is re ... | 2017 | 28665722 |
| engineered newcastle disease virus expressing the f and g proteins of ampv-c confers protection against challenges in turkeys. | avian metapneumovirus (ampv) infects the respiratory and reproductive tracts of domestic poultry, resulting in substantial economic losses for producers. live attenuated vaccines appear to be the most effective in countries where the disease is prevalent. however, reversion to virulence has been demonstrated in several studies. therefore, the development of a stable and safe next generation vaccine against the ampv disease is needed. in the present study, we generated a recombinant newcastle dis ... | 2017 | 28642611 |
| health status of free-ranging ring-necked pheasant chicks (phasianus colchicus) in north-western germany. | being a typical ground-breeding bird of the agricultural landscape in germany, the pheasant has experienced a strong and persistent population decline with a hitherto unexplained cause. contributing factors to the ongoing negative trend, such as the effects of pesticides, diseases, predation, increase in traffic and reduced fallow periods, are currently being controversially discussed. in the present study, 62 free-ranging pheasant chicks were caught within a two-year period in three federal sta ... | 2020 | 32544211 |
| first identification and molecular characterization of avian metapneumovirus subtype b from chickens in greece. | avian metapneumovirus (ampv) is considered a major pathogen for turkeys but its impact on chicken production is still partially neglected, even though it is fully acknowledged as a primary pathogen in chickens as well. the lack of structured diagnostic surveys does not allow a pervasive understanding of ampv epidemiology. being that ampv is almost an everyday challenge for farmers and veterinarians, a more accurate report of its presence should be detailed, posing the basis for a deep and global ... | 2017 | 28957007 |
| characterization of novel, pathogenic field strains of infectious bronchitis virus (ibv) in poultry in trinidad and tobago. | avian coronaviruses, including infectious bronchitis virus (ibv) and turkey coronavirus (tcov), are economically important viruses affecting poultry worldwide. ibv is responsible for causing severe losses to the commercial poultry sector globally. the objectives of this study were to identify the viruses that were causing outbreaks of severe respiratory disease in chickens in trinidad and tobago (t&t) and to characterize the strains. swab samples were collected from birds showing severe respirat ... | 2020 | 32438523 |
| complete genome sequence of an avian metapneumovirus subtype b strain from hungary. | avian metapneumoviruses (ampvs), which have been reported in many countries, cause acute upper respiratory tract disease in chickens and turkeys. using next-generation sequencing, we report here the complete genome sequence of an ampv subtype b strain that was isolated from a turkey in hungary in 1989. | 2020 | 32381608 |
| molecular epidemiology of respiratory viruses in commercial chicken flocks in pakistan from 2014 through to 2016. | viral diseases are a matter of great concern for poultry farmers in pakistan. multiple common viral respiratory diseases (cvrds) cause huge economic losses in the poultry industry. the prevalence of cvrds in many countries, including pakistan, is not clearly understood. | 2019 | 31638995 |
| comparative protective immunity provided by live vaccines of newcastle disease virus or avian metapneumovirus when co-administered alongside classical and variant strains of infectious bronchitis virus in day-old broiler chicks. | this study reports on the simultaneous administration of live ndv or ampv subtype b vaccines alongside two live ibv (massachusetts-h120 and 793b-cr88) vaccines in day-old maternal-antibody positive commercial broiler chicks. in the first experiment, chicks were divided into four groups; one unvaccinated and three groups vaccinated with live ndv vg/ga-avinew, live h120 + cr88, or vg/ga-avinew + h120 + cr88. in the second experiment, live ampv subtype b vaccine was used in place of ndv. clinical s ... | 2019 | 31607602 |
| the contribution of the immune response to enhanced colibacillosis upon preceding viral respiratory infection in broiler chicken in a dual infection model. | colibacillosis in chickens caused by avian pathogenic escherichia coli (apec) is known to be aggravated by preceding infections with infectious bronchitis virus (ibv), newcastle disease virus (ndv) and avian metapneumovirus (ampv). the mechanism behind these virus-induced predispositions for secondary bacterial infections is poorly understood. here we set out to investigate the immunopathogenesis of enhanced respiratory colibacillosis after preceding infections with these three viruses. broilers ... | 2021 | 34126552 |
| impact of nematode infections on non-specific and vaccine-induced humoral immunity in dual-purpose or layer-type chicken genotypes. | nematode infections may induce immune-modulatory effects and influence host-immune responses to other pathogens. the aim of the study was to investigate whether a mixed nematode-infection influences non-specific and vaccine-induced humoral immunity against newcastle disease virus (ndv), infectious bronchitis virus (ibv), and avian metapneumovirus (ampv) in already vaccinated hens of a dual-purpose (lohmann dual, ld) or a layer genotype (lohmann brown plus; lb). until 17 weeks-of-age, ld (n = 70) ... | 2021 | 34046445 |
| molecular epidemiology and genotyping of infectious bronchitis virus and avian metapneumovirus in backyard and commercial chickens in jimma zone, southwestern ethiopia. | poultry production plays a relevant role in the ethiopian economy and represents a source of poverty alleviation for several social classes. infectious diseases can therefore significantly impact the economy and welfare. despite infectious bronchitis virus (ibv) and avian metapneumovirus (ampv) being present, the knowledge of their epidemiology and impact is extremely limited. in the present work, a cross-sectional study based on 500 tracheal swabs collected from 50 intensive and backyard unvacc ... | 2020 | 33255570 |
| seroprevalences of specific antibodies against avian pathogens in free-ranging ring-necked pheasants (phasianus colchicus) in northwestern germany. | infectious diseases in captive pheasants (phasianus colchicus) are well known, but there is a lack of knowledge about occurrence and distribution of pathogens in free-ranging pheasants in germany. we investigated 604 sera from hunted pheasants and 152 sera from wild caught pheasants between 2011 to 2015, with the aim to determine the prevalence of specific antibodies against different viruses: avian influenza virus (aiv) of subtypes h5, h7, h9, paramyxovirus type 1 (pmv-1), avian encephalomyelit ... | 2021 | 34347834 |
| host specificity of avian metapneumoviruses. | to date, four subgroups of avian metapneumoviruses have been defined (ampv-a, b, c and d) based on genetic and antigenic differences. the extent of infection in the three principal species (turkeys, chickens and ducks) by these subgroups is, however, not well defined. here, a series of controlled and ethically approved experimental infections were performed in specific pathogen-free turkeys, chickens and ducks with each of the four ampv subgroups. for subgroup c, one strain isolated from turkeys ... | 2019 | 30777452 |
| efficacy of a novel avian metapneumovirus live vaccine candidate based on vaccination route and age. | this article describes a series of animal studies for the development of an avian metapneumovirus (ampv) live vaccine. although ampv causes continual economic loss in the poultry industry, there are no live ampv vaccines available in korea. furthermore, information is limited with respect to standard field practices for vaccinations at an early age. here, the development of an ampv live vaccine was attempted, and its efficacy was investigated with respect to the vaccination route and age to deve ... | 2020 | 33518307 |
| novel inactivated subtype b avian metapneumovirus vaccine induced humoral and cellular immune responses. | avian metapneumovirus (ampv), a highly contagious agent, is widespread and causes acute upper respiratory tract disease in chickens and turkeys. however, currently, there is no vaccine licensed in china. herein, we describe the development of an inactivated ampv/b vaccine using the ampv/b strain ln16. combined with a novel adjuvant containing immune-stimulating complexes (iscoms), the novel vaccine could induce high virus-specific and vn antibodies. in addition, it activated b and t lymphocytes ... | 2020 | 33327513 |
| genomic sequence and pathogenicity of the first avian metapneumovirus subtype b isolated from chicken in china. | avian metapneumovirus (ampv), which has been reported in many countries, causes an acute upper respiratory tract disease in chickens and turkeys. although ampv was first detected in china in 1999, there has been no further effort to isolate and characterize the ampv subtype b (ampv/b) from field outbreaks. in the present study, we used vero cells to culture a viral strain, ln16, isolated from chickens with swollen head syndrome. the results of rt-pcr, indirect immunofluorescent antibody, and g g ... | 2019 | 30593377 |
| co-circulation of genetically diverse population of vaccine related and unrelated respiratory mycoplasmas and viruses in uk poultry flocks with health or production problems. | respiratory diseases continue to have a major impact on poultry health, welfare and productivity. however, little information is available on their current status in uk poultry flocks. we investigated the presence of four economically important respiratory pathogens in healthy or problematic flocks; infectious bronchitis virus (ibv), avian metapneumovirus (ampv), mycoplasma gallisepticum (mg) and mycoplasma synoviae (ms). samples from 131 uk poultry flocks were received during the 12 month study ... | 2018 | 30322525 |
| serosurvey of avian metapneumovirus, orithobacterium rhinotracheale, and chlamydia psittaci and their potential association with avian airsacculitis. | seasonal outbreaks of airsacculitis in china's poultry cause great economic losses annually. this study tried to unveil the potential role of avian metapneumovirus (ampv), ornithobacterium rhinotracheale (ort) and chlamydia psittaci (cps) in avian airsacculitis. a serological investigation of 673 breeder chickens and a case-controlled study of 430 birds were undertaken. results showed that infection with ampv, ort, and cps was highly associated with the disease. the correlation between ampv and ... | 2018 | 29866224 |
| prevalence of avian metapneumovirus subtype b in live bird market in gilan province, iran. | avian metapneumovirus (ampv), also known as avian pneumovirus or turkey rhinotracheitis virus, is the causative agent of turkey rhinotracheitis and swollen head syndrome in chickens. four ampv subgroups (a-d) have been reported previously based on their genetic and antigenic differences. evidence suggests that the live bird markets (lbms) play an important role in the epidemiology of the avian viral diseases. a total number of 450 oropharyngeal samples from eight different species of birds (migr ... | 2018 | 29719670 |
| preliminary antigenic characterization of an avian pneumovirus isolated from commercial turkeys in colorado, usa. | an avian pneumovirus (apv) isolated from turkeys showing respiratory disease in colorado, usa, shared some characteristics with earlier subgroup a and b apv strains. this virus, designated the colorado isolate (colorado), when used after either seven passages in chick embryo fibroblasts (cef), or seven passages in cef followed by six turkey passages, induced clinical signs in turkeys that were similar to those caused by earlier apv strains. although it induced an antibody response in specific pa ... | 1999 | 27266432 |
| discovery and characterization of novel rna viruses in aquatic north american wild birds. | wild birds are recognized viral reservoirs but our understanding about avian viral diversity is limited. we describe here three novel rna viruses that we identified in oropharyngeal/cloacal swabs collected from wild birds. the complete genome of a novel gull metapneumovirus (gumpv b29) was determined. phylogenetic analyses indicated that this virus could represent a novel avian metapneumovirus (ampv) sub-group, intermediate between ampv-c and the subgroup of the other ampvs. this virus was detec ... | 2019 | 31438486 |
| genome sequence of a divergent avian metapneumovirus from a monk parakeet (myiopsitta monachus). | here, we report the coding-complete genome sequence of an avian metapneumovirus from a monk parakeet (myiopsitta monachus), identified by metagenomic next-generation sequencing during an investigation into a disease outbreak in a captive parrot breeding facility. based on divergence from known strains, this sequence represents a new subgroup of avian metapneumovirus. | 2019 | 31000555 |
| development of a recombinant nucleocapsid based indirect elisa for the detection of antibodies to avian metapneumovirus subtypes, a, b, and c. | nucleocapsid (n) protein is the most highly expressed of all avian metapneumovirus (ampv) viral proteins and stimulates a substantial immune response in infected animals. codon optimized recombinant n (rec-n) protein from ampv subtypes a, b, and c were expressed using the baculoviral expression system in trichoplusia ni (tni) insect cells. a mixture of purified rec-n antigens from each subtype was used as a coating antigen and was evaluated in indirect elisa (ielisa) to assess antibody response ... | 2020 | 33227621 |