1,721,026 research outputs found
Vaccine Interaction and Protection against Virulent Avian Metapneumovirus (aMPV) Challenge after Combined Administration of Newcastle Disease and aMPV Live Vaccines to Day-Old Turkeys
Full text linkNewcastle disease virus (NDV) and avian metapneumovirus (aMPV) are among the most impactful pathogens affecting the turkey industry. Since turkeys are routinely immunized against both diseases, the hatchery administration of the combined respective live vaccines would offer remarkable practical advantages. However, the compatibility of NDV and aMPV vaccines has not yet been experimentally demonstrated in this species. To address this issue, an aMPV subtype B live vaccine was administered to day-old poults either alone or in combination with one of two different ND vaccines. The birds were then challenged with a virulent aMPV subtype B strain, clinical signs were recorded and aMPV and NDV vaccine replication and humoral immune response were assessed. All results supported the absence of any interference hampering protection against aMPV, with no significant differences in terms of clinical scoring. In addition, the mean aMPV vaccine viral titers and antibody titers measured in the dual vaccinated groups were comparable or even higher than in the group vaccinated solely against aMPV. Lastly, based on the NDV viral and antibody titers, the combined aMPV and NDV vaccination does not seem to interfere with protection against NDV, although further studies involving an actual ND challenge will be necessary to fully demonstrate this hypothesis
Identificazioni di marker molecolari per la differenziazione di un vaccino IBV genotipo QX
No full textIBV genotype QX causes suf cient disease in Europe for several commercial com- panies to have started developing live attenuated vaccines. Here, one of those vac- cines (L1148) was fully consensus sequenced alongside its progenitor eld strain (1148-A) to determine vaccines markers, thereby enabling detection on farms. Twenty eight single nucleotide substitutions were associated with the 1148-A atten- uation, of which any combination can identify vaccine L1148 in the eld. Sixteen substitutions resulted in amino acid coding changes of which half were in spike. One change in the 1b gene altered the normally highly conserved nal 5 nucleotides of the transcription regulatory sequence of the S gene, common to all IBV QX genes. No mutations can currently be associated with the attenuation process. Field vac- cination strategies would greatly bene t by such comparative sequence data being mandatorily submitted to regulators prior to vaccine release following a successful registration process
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Detection and differentiation of Avian Metapneumovirus by Real Time Rt-PCR
No full textDirect diagnosis of avian Metapneumovirus (AMPV) infections rely on molecular techniques more than on virus isolation due to the fastidious nature of the virus. Six real-time reverse transcription PCR (RRT-PCR) protocols for the detection and differentiation of AMPV subtype A and B were developed in N (two tests), F, SH (two tests) and G genes. Five assays used SYBR Green I as detection system, and one molecular beacon probes. Specificity was evaluated using various AMPV strains, Newcastle disease, Infectious laryngotracheitis and Infectious bronchitis viruses. All tests were able to detect AMPVs and failed to detect non-AMPV viruses, and five out of six of them were also able to discriminate between AMPV A and B subtypes. Sensitivity was determined using serial dilutions of RNA from AMPV of both subtypes. The best results in terms of specificity and sensitivity was given by the RRT-PCR protocol designed in the SH gene
Impiego di metapneumovirus aviare come possibile vaccino vivo ricombinante per l’espressione di proteine immunogene del Coronavirus della Bronchite infettiva
No full textThe study investigates the ability of subtype A Avian metapneumovirus (AMPV) to accept foreign genes and be used as a vector for delivery of Infectious bronchitis virus (IBV) QX genes to chickens. Initially the GFP gene was added to AMPV at all gene junctions in conjunction with the development of cassetted full length DNA AMPV copies. After 3 recombinant viruses had been recovered by reverse genetics, GFP positions supporting gene expression while maintaining virus viability in vitro, were determined. Subsequently, either S1 or nucleocapsid (N) genes of IBV were positioned between AMPV M and F genes, while later a recombinant was prepared by inserting S1 and N at AMPV MF and GL junctions respectively. Immunofluorescent antibody staining showed that all recombinants expressed the inserted IBV genes in vitro and furthermore, all recombinant viruses were found to be highly stable during serial passage. Eyedrop inoculation of chickens with some AMPV-IBV recombinants at one-day-old induced protection against virulent IBV QX challenge 3 weeks later, as assessed by greater motility of tracheal cilia from chickens receiving the recombinants. Nonetheless evidence of AMPV/IBV seroconversion, or major recombinant tracheal replication, were largely absent
Evidenze sperimentali della resistenza del Piccione (Columba Livia) all’infezione da Metapneumovirus aviare e della sua irrilevanza nella trasmissione dell’infezione al tacchino
No full textAvian metapneumovirus (AMPV) causes an upper respiratory tract infection in turkeys leading to turkey rhinotracheitis. In other avian species, including chickens, it is also involved in the etiology of multifactorial diseases such as swollen head syndrome. Sensitivity of wild birds to AMPV and their role in maintaining and spreading the virus to poultry is still a matter of debate. Recently the sensitivity of pigeons to AMPV of subtype A or B has been claimed, based on very limited PCR detections from wild or experimentally infected birds. In order to have conclusive evidence regarding the sensitivity of pigeons to AMPV of subtype B and its role in spreading the virus to turkeys, two experimental trials were planned in secure isolation conditions. In trial 1 two isolators were modified to host turkeys and pigeons in the same environment, separated only by a net. Drinkers were shared between groups. Pigeons were infected with AMPV and housed in one isolator with naïve turkeys. Similarly turkeys were infected and housed with naïve pigeons. Additional turkeys and pigeons were kept in different isolators as uninfected controls. Post-infection clinical signs, virus shedding and immune response were assessed for three weeks. In trial 2, commercial two-weeks old turkeys were divided in two groups and housed in two different isolators. Birds in isolator A were challenged as previously described. Four days post-infection, 7 weeks old naïve pigeons were introduced in the isolator A and kept with the infected turkeys for 24 hours, then removed, sprayed with 0,5 % of Wirkon S® solution. After 10 minutes, pigeons were rinsed with water, dried, and introduced in the isolator B, where 10 naïve turkeys were housed. Clinical sign were monitored for 10 days. Pigeons were found refractory to AMPV experimental infection and neither able to spread the virus to naïve turkeys. Our paper shows that pigeons are highly unlikely to play any relevant role in the environmental spread of subtype B AMPV. Pigeons are not biological vector or reservoir species for AMPV subtype B
Combined administration of Newcastle Disease and Avian Metapneumovirus live vaccine to one-day-old turkeys: vaccine interaction and protection against virulent AMPV
No full textThe combined administration of Newcastle Disease (ND) and Avian metapneumovirus (AMPV) live vaccines in turkey hatcheries is advantageous, but compatibility has not yet been experimentally demonstrated. To investigate any possible interference between the two vaccines, AMPV subtype B live vaccine was given to one-day-old turkeys either alone or in combination with two different ND vaccines of the B1 and VG/GA strains. AMPV and NDV post vaccination shedding and humoral immune response were assessed. Results showed that, following single or combined vaccinations, both AMPV and/or ND vaccine virus were detected in the respiratory tract of all of the birds in all the groups. In addition, birds were protected from virulent AMPV virus challenge and differences in clinical signs between groups vaccinated with AMPV vaccine alone or in combination with ND vaccine were not statistically significant
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Dati epidemiologici sulla circolazione in Italia del nuovo genotipo IBDV ITA
No full textSignifi cant economic losses can affect the poultry industry due to the consequences of immunosuppression induced by viral infections. This study reports the results of a survey, conducted in 2012-2014 on 59 farms located in Northern and Central Italy, aimed to investigate the diffusion of the new genotipe ITA of infectious bursal disease virus (IBDV) recently detected in Italy. All fl ocks, out of one, were vaccinated for IBD. Seventeen longitudinal studies and 42 “one off” sampling performed during routine diagnostic activity for IBD, were performed. Samples of the Bursa of Fabricius were collected for virus detection by a RT-PCR protocol designed in the hypervariable region of the VP2, from 10 birds per fl ock, at different time of life.
The RT-PCR products were sequenced and the sequences aligned with the available database logged omologous sequences. The IBDV strain ITA was the most detected genotype, being found in 31 out of 59 farms. The actual pathogenicity of the IBDV ITA strain, as well as the degree of protection offered by common vaccination schedules, will be further investigated
- …
