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Catelli E. - One of the best experts on this subject based on the ideXlab platform.
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Infezione sperimentale con Metapneumovirus aviare e Mycoplasma synoviae in polli da carne: risultati preliminari
2016Co-Authors: Moronato, Maria Luisa, Cecchinato Mattia, Catelli E., Franzo Giovanni, Gobbo Federica, Mainenti M., Catania S., Martini MarcoAbstract:Avian Metapneumovirus is a respiratory pathogen causing the Turkey Rhinotracheitis (TRT). It is associated to the Swollen Head Syndrome in broilers, but its role as primary respiratory pathogen in this host is nowadays not completely defined. Mycoplasma synpviae is a respiratory bacterial pathogen whose importance increased in the last few years. The greater relevance of aMPV and MS in the poultry sector and the lack of experimental studies regarding their co-infection in broilers led to this infection model for the reproduction of clinical respiratory disease. The preliminary results evidenced by the clinical and laboratory investigations suggests the possible synergic interaction between aMPV and MS
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Rapid detection of subtype B Avian Metapneumoviruses using RT-PCR restriction endonuclease digestion indicates field circulation of vaccine derived viruses in older turkeys
'Informa UK Limited', 2014Co-Authors: Lupini C., Cecchinato Mattia, Pesente P., Rossi G., Naylor C. J., Giovanardi D., Catelli E.Abstract:Live vaccines predominantly control Avian Metapneumovirus (AMPV) infection in the poultry industry but vaccine virus can be found for extended periods after application. The most frequently used AMPV vaccine in Italy, VCO3 subtype B, was shown to contain a unique Tru9I restriction endonuclease (RE) site within the amplicon resulting from of a commonly used AMPV diagnostic RT-nested PCR. Analysis of European and database logged subtype B AMPV sequences confirmed the sequence only occurred in the VC03 vaccine. A subsequent RT-PCR-RE study of field samples, collected from turkeys between 2007 and 2012, detected subtype B vaccine derived strains in twelve of ninety tested samples, collected from birds below 12 weeks of age
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AN UPDATE ON THE EPIDEMIOLOGY OF Avian Metapneumovirus IN ITALY
2014Co-Authors: Cecchinato Mattia, Lupini C., Franzo Giovanni, Martini Marco, Naylor C. J., Drigo Michele, Laconi A., Morandini E., Catelli E.Abstract:A molecular survey on Avian Metapneumovirus (aMPV) diffusion was performed from 2011 to 2013 in 122 turkey and 48 broiler farms, located in a densely populated poultry area of Northern Italy. Turkeys were all vaccinated at 1 day of age in the hatchery. aMPV was detected using RTnested PCR or qRT-PCR; both tests are able to detect and differentiate aMPV subtypes A and B. All samples but one resulted positive for aMPV subtype B confirming the high prevalence of this subtype in Italy. The majority of aMPV detections were of field origin, circulating mainly in 9 to 12-week-old turkeys and 5 to 7 week-old broilers, showing respiratory signs. The reasons for vaccine failure could be due to field virus changes occurred in key antigenic regions, which allow virus replication and disease in well-vaccinated birds. Strains of vaccine origin were detected in turkeys with a high prevalence during the first few weeks after vaccination with aMPV live vaccines. This confirmed the pattern previously seen where vaccine viruses were shown to persist on farm for 4-5 weeks. Uniquely in this study, vaccine derived strains were detected in older turkeys of up to 84 days of age. Moreover, sequence analysis of F and G protein genes of selected strains was performed
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First evidence of Avian Metapneumovirus subtype A infection in turkeys in Egypt.
'Springer Science and Business Media LLC', 2014Co-Authors: Aa ,abdel Azeem, Lupini C., Catelli E., Franzo Giovanni, Martini Marco, Drigo Michele, Dalle Zotte Antonella, Cecchinato MattiaAbstract:Although Avian Metapneumovirus (aMPV) infection has been reported in most regions of the world, to date, only subtype B has been detected in Egypt. At the end of November 2013, dry oropharyngeal swabs were collected during an outbreak of respiratory diseases in a free-range, multi-age turkey dealer farm in Northern Upper Egypt. The clinical signs that appeared when turkeys were 3 weeks-old were characterized by ocular and nasal discharge and swelling of sinuses. aMPV of subtype A was detected by real-time reverse transcription-polymerase chain reaction. In order to confirm the results and obtain more information on the molecular characteristics of the virus, F and G protein genes were partially sequenced and compared with previously published sequences deposited in GenBank by using BLAST. Subtype of the strain was confirmed by sequencing of partial F and G protein genes. The highest percentages of identity were observed when G sequence of the Egyptian strain was compared with the sequence of an aMPV-A isolated in Nigeria (96.4 %) and when the F sequence was compared with strains isolated respectively in Italy and in UK (97.1 %). Moreover, the alignment of the sequences with commercial subtype A vaccine or vaccine-derived strains showed differences in the Egyptian strain that indicate its probable field origin. The detection of aMPV in the investigated turkey flock highlights some relevant epidemiological issues regarding the role that multi-age farms and dealers may play in perpetuating aMPV infection within and among farms. To our knowledge, this is the first report of aMPV subtype A in Egypt
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A sensitive, reproducible, and economic real-time reverse transcription PCR detecting Avian Metapneumovirus subtypes A and B
'American Association of Avian Pathologists (AAAP)', 2014Co-Authors: Franzo G, Lupini C., Catelli E., Laconi A., Drigo M, Martini M, Bonci M, Naylor C.j., Cecchinato M.Abstract:Use of real-time PCR is increasing in the diagnosis of infectious disease due to its sensitivity, specificity, and speed of detection. These characteristics make it particularly suited for the diagnosis of viral infections, like Avian Metapneumovirus (AMPV), for which effective control benefits from continuously updated knowledge of the epidemiological situation. Other real-time reverse transcription (RT)-PCRs have been published based on highly specific fluorescent dye-labeled probes, but they have high initial cost, complex validation, and a marked susceptibility to the genetic variability of their target sequence. With this in mind, we developed and validated a SYBR Green I-based quantitative RT-PCR for the detection of the two most prevalent AMPV subtypes (i.e., subtypes A and B). The assay demonstrated an analytical sensitivity comparable with that of a previously published real-time RT-PCR and the ability to detect RNA equivalent to approximately 0.5 infectious doses for both A and B subtypes. The high efficiency and linearity between viral titer and crossing point displayed for both subtypes make it suited for viral quantification. Optimization of reaction conditions and the implementation of melting curve analysis guaranteed the high specificity of the assay. The stable melting temperature difference between the two subtypes indicated the possibility of subtyping through melting temperature analysis. These characteristics make our assay a sensitive, specific, and rapid tool, enabling contemporaneous detection, quantification, and discrimination of AMPV subtype A and B
Elena Catelli - One of the best experts on this subject based on the ideXlab platform.
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Avian Metapneumovirus subtype B around Europe: a phylodynamic reconstruction
Veterinary Research, 2020Co-Authors: Giovanni Franzo, Claudia Maria Tucciarone, Caterina Lupini, Elena Catelli, Matteo Legnardi, Giulia Mescolini, Giulia Quaglia, Mattia CecchinatoAbstract:AbstractAvian 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 phylodynamic and biostatistical approaches to reconstruct the viral spreading over time and the role of different hosts on its evolution. After aMPV-B introduction, approximatively in 1985 in France, the infection spread was relatively quick, involving the Western and Mediterranean Europe until the end of the 1990s, and then spreading westwards at the beginning of the new millennium, in parallel with an increase of viral population size. In the following period, a wider mixing among aMPV-B strains detected in eastern and western countries could be observed. Most of the within-country genetic heterogeneity was ascribable to single or few introduction events, followed by local circulation. This, combined with the high evolutionary rate herein demonstrated, led to the establishment of genetically and phenotypically different clusters among countries, which could affect the efficacy of natural or vaccine-induced immunity and should be accounted for when planning control measure implementation. On the contrary, while a significant strain exchange was proven among turkey, guinea fowl and chicken, no evidence of differential selective pressures or specific amino-acid mutations was observed, suggesting that no host adaptation is occurring.
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Longitudinal field studies of Avian Metapneumovirus and Turkey Hemorrhagic Enteritis Virus in turkeys suffering from colibacillosis associated mortality
Veterinary Research Communications, 2014Co-Authors: Davide Giovanardi, Caterina Lupini, Patrizia Pesente, Giulia Rossi, Giovanni Ortali, Elena CatelliAbstract:The aim of this study was to evaluate if the exposure to Avian Metapneumovirus (aMPV) and/or to Turkey hemorrhagic enteritis virus (THEV) was significant for the induction of episodes of colibacillosis in aMPV and THEV vaccinated turkeys. Colibacillosis-associated mortality was recorded and longitudinal virological studies performed in three consecutive turkey flocks reared in the same farm. aMPV and THEV diagnostic swabs and blood samples were made once a week up to 14 weeks of age. Swabs were processed by molecular techniques for viruses detection and antibody titres were evaluated. Field subtype B aMPVs were detected in all flocks at different ages of life always associated with respiratory signs and increase of colibacillosis-associated mortality. THEV has been consistently detected in all flocks since the 9th week of age. Vaccination with a single dose of the THEV commercial inactivated vaccine available in Italy seems does not protect the birds from the infection. Sequence comparison of the hexon protein of one of the THEV strains detected, and strains isolated worldwide, revealed high similarity between them. These results are consistent with the notion that the hexon protein, being the major antigenic component of the virus, is highly conserved between the strains. Results showed that field aMPV infection is directly correlated to colibacillosis-associated mortality. Less clear appears the role of THEV because the endemicity of aMPV makes difficult to evaluate its role in predisposing colibacillosis in absence of aMPV. It would be interesting to further investigate this issue through experimental trials in secure isolation conditions.
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Reversion to virulence of a subtype B Avian Metapneumovirus vaccine: Is it time for regulators to require availability of vaccine progenitors?
'Elsevier BV', 2014Co-Authors: Cecchinato Mattia, Caterina Lupini, Elena Catelli, Enrico Ricchizzi, S. Prosperi, J. C. NaylorAbstract:Empirically derived live Avian Metapneumovirus (AMPV) vaccines developed during the late 80s and early 90s have generally performed well in controlling turkey rhinotracheitis. Nonetheless, unstable attenuation was previously demonstrated in an AMPV subtype A vaccine. Until now this had not been investigated in subtype B vaccines due to lack of any similar availability of a vaccine progenitor or its sequence. The publication of the full genome sequence for the VCO3 vaccine progenitor facilitated a conclusive investigation of two AMPVs isolated from poults on a farm which had been vaccinated with VCO3 derived vaccine. Full genome sequencing of the isolates and their comparison to sequences of the vaccine and its progenitor, confirmed their vaccine origin. After determining the absence of extraneous infectious agents, one of these virus isolates was inoculated into 1-day-old turkeys in disease secure isolators and shown to cause disease with a severity similar to that caused by virulent field virus. This suggests that instability in live AMPV vaccines may be generalized and highlights the need for availability of vaccine progenitor sequences for the field assessment of all live viral vaccines
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Vaccines interaction and protection against virulent Avian Metapneumovirus (AMPV) challenge after combined administration of Newcastle disease and AMPV live vaccines to one-day old turkeys
Lierz M. Heffels-Redmann U. Enderlein D., 2014Co-Authors: Elena Catelli, Cecchinato Mattia, V. Listorti, S., Mu 1oz O. Pogoreltseva, C. Terregino, V. Felice, Caterina LupiniAbstract:The combined administration of Newcastle Disease (ND) and Avian Metapneumovirus (AMPV) live vaccines to one-day-old turkeys in the hatchery is advantageous, but compatibility has not yet been experimentally demonstrated. To investigate this issue, AMPV subtype B live vaccine strain VCO3 was given to one-day old turkeys either alone or in combination with ND vaccine strain B1 or strain VG/GA, in secure isolation conditions. Post-vaccination viral shedding and humoral immune response were assessed. Furthermore birds were challenged with a virulent AMPV and the protection from clinical signs was evaluated. Results showed that concurrent live vaccination with AMPV and NDV (either strain B1 or VG/GA) of 1-day-old turkeys confers good protection after AMPV challenge and causes a synergic effect in AMPV antibody response, probably due to higher AMPV vaccine replication when it is given in combination with ND vaccines. Further studies are required to show if protection after NDV challenge is affected by ND and AMPV combined vaccination
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LONGITUDINAL FIELD STUDIES OF Avian Metapneumovirus AND TURKEY HEMORRHAGIC ENTERITIS VIRUS IN TURKEYS SUFFERING FROM COLIBACILLOSIS-ASSOCIATED MORTALITY
place:Giessen, 2014Co-Authors: Giovanardi D., Pesente P., Lupini C., Rossi G., Elena CatelliAbstract:This study evaluated if, in field conditions, the infection with Avian Metapneumovirus (AMPV) and/or Turkey Hemorrhagic Enteritis Virus (THEV) was significant for the induction of episodes of colibacillosis in AMPV and THEV vaccinated turkeys. Colibacillosis-associated mortality was recorded and longitudinal virological studies performed in three consecutive turkey flocks reared in the same farm. AMPV and THEV diagnostic swabs and blood samples were made once a week up to 14 weeks of age. Swabs were processed by molecular techniques, and antibody titres were evaluated by ELISA. When AMPV of subtype B was detected, samples were subjected to a restriction endonuclease digestion protocol to discriminate between field and vaccine strains. Field strains were detected in all flocks at different ages of life, always associated with respiratory signs and increase of colibacillosis-associated mortality. THEV has been consistently detected in all flocks since the 9th week of age. Vaccination with a single dose of the THEV commercial inactivated vaccine available in Italy seems do not protect the birds from the infection. Sequence comparison of the hexon protein of one of the THEV strains detected, and strains isolated worldwide, revealed high similarity between them. These results are consistent with the notion that the hexon protein, being the major antigenic component of the virus, is highly conserved between the strains. Results showed that field AMPV infection is correlated to colibacillosis-associated mortality. Less clear appears the role of THEV because the endemicity of AMPV makes difficult to evaluate its role in predisposing colibacillosis in absence of AMPV
Cecchinato Mattia - One of the best experts on this subject based on the ideXlab platform.
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Two similar commercial live attenuated AMPV vaccines prepared by random passage of the identical field isolate, have unrelated sequences
'Elsevier BV', 2019Co-Authors: Laconi Andrea, Cecchinato Mattia, Catelli Elena, Naylor, Clive JAbstract:Since late \u201880 s Avian Metapneumovirus subtype A causes sufficient disease in Europe for commercial companies to have started developing live attenuated vaccines. Here, two of those vaccines were fully consensus sequenced alongside their progenitor field strain (#8544). Sequences comparison shows that the attenuation of field strain #8544 was associated with no common substitutions between the two derived vaccines. This finding suggests that the attenuation of field viruses via serial passage on cell cultures or tissues is the result of a random process, rather than a mechanism aiming to achieve a specific sequence. Furthermore, field vaccination strategies would greatly benefit by the unambiguous vaccine markers identified in this study, enabling a prompt and confident vaccines detection
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Avian Metapneumovirus circulation in Italian broiler farms
'Oxford University Press (OUP)', 2018Co-Authors: Tucciarone, Claudia Maria, Catelli Elena, Franzo Giovanni, Lupini Caterina, Alejo, Carolina Torres, Listorti Valeria, Mescolini Giulia, Martini Marco, Cecchinato MattiaAbstract: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 tract swabs were collected and processed by A and B subtype-specific multiplex real-time reverse transcription PCR (RT-PCR). Samples were also screened for infectious bronchitis virus (IBV) by generic RT-PCR and sequencing. Productive data and respiratory signs were detailed where possible. The high prevalence of aMPV was confirmed in broilers older than 26 d and also attested in IBV-negative farms. All aMPV detections belonged to subtype B. Italian strain genetic variability was evaluated by the partial attachment (G) gene sequencing of selected strains and compared with contemporary turkey strains and previously published aMPV references, revealing no host specificity and the progressive evolution of this virus in Italy
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First Report of Avian Metapneumovirus Subtype B Field Strain in a Romanian Broiler Flock during an Outbreak of Respiratory Disease
'American Association of Avian Pathologists (AAAP)', 2017Co-Authors: Franzo Giovanni, Tucciarone, Claudia Maria, Enache Mirel, Bejan Violeta, Ramon Gema, Koutoulis, Konstantinos C., Cecchinato MattiaAbstract: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 reported for the first time. The phylogenetic analysis based on the partial G gene sequence demonstrates the close relationship of the Romanian virus with a group of recently emerged Italian field strains for which vaccine-induced protection was experimentally proven to be partial. These preliminary results allow us to hypothesize the spreading of vaccine-escaping aMPV subtype B strains through Europe and, consequently, dictate the carrying out of a more systematic survey to confirm this theory and enforce adequate countermeasures
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Real-time PCR data express the different distribution of Avian Metapneumovirus and Mycoplasma synoviae in broiler chickens experimentally infected with one or both pathogens. Preliminary results.
2017Co-Authors: Gobbo Federica, Cecchinato Mattia, Franzo Giovanni, Moronato, Maria Luisa, Martini MarcoAbstract:Mycoplasma synoviae (MS) is an Avian bacterial pathogen whose importance has grown considerably in the last years in many European countries (1). MS infection is related to respiratory disease, synovitis and EAA (2). As for many other pathogens, the severity of the respiratory disease can be enhanced by the co-infection with other viral or bacterial pathogens. Although the increased relevance of Metapneumovirus (aMPV) as a cause of respiratory disease in broilers in the field, less is known regarding its co-infection with Mycoplasma spp. in chickens and especially with MS. The aim of the present study was to experimentally reproduce the infection between aMPV and MS in commercial broiler chickens. The possible synergistic relationship between the two pathogens was evaluated through the analysis of the real-time PCR (aMPV and MS) results. For the experimental study, 160 1-day-old chicks were randomly divided in 4 groups (A, B, C and E) and housed in Montair\uae isolators. Group A (positive AMPV control) was inoculated via the oculo-nasal route with Avian Metapneumovirus, group C received, via the same route, Mycoplasma synoviae and group B was infected with both pathogens (oculo-nasal administration). Group E acted as negative control. Group A and B received aMPV at day 15 of age and 3 days later (18-days old) group B and C were infected with MS. The experimental design was chosen in order to reproduce as much as possible the natural infection. At different times after the aMPV infection 5 animals/each group were randomly selected for post mortem evaluations, swabs were collected from respiratory and systemic tissues and submitted to real time aMPV PCR (3) and real time MS PCR (4). During the trial, which lasted until day 35 of age of the animals, serological and tissue specimens were collected for further investigations (data not shown). The infections were successfully reproduced and chickens showed clinical respiratory signs. There were no significant differences between the A (aMPV) and B (aMPV+MS) group in the total number of aMPV positive PCR, but the trend in A and B during the time was different, actually, in the B group the outcome of positive aMPV PCR was delayed and lengthen during the trial and the nasal turbinates were positive for the whole length of it. The B group (aMPV+MS) showed a higher number of positive PCR for MS, either in the respiratory tract (especially in nasal turbinates, trachea and lungs) or in systemic tissues, such as spleen, cloaca, kidney, and brain, expressing a wider dissemination of Mycoplasma synoviae in the animals. The preliminary data regarding the real time PCR results suggests the possible mutual/additive relationship between the two pathogens in broiler chickens, which seems to be related to a wider and a prolonged presence of MS and aMPV in the host
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First Identification and Molecular Characterization of Avian Metapneumovirus Subtype B from Chickens in Greece
'American Association of Avian Pathologists (AAAP)', 2017Co-Authors: Tucciarone, Claudia Maria, Franzo Giovanni, Andreopoulou Marianna, Prentza Zoi, Chaligiannis Ilias, Cecchinato MattiaAbstract: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 epidemiologic analysis. With these premises, the present work aims to report the first detection and molecular characterization of aMPV subtype B field strains from unvaccinated chickens in Greece. The Greek strains appear to be phylogenetically related among each other and with other recent Mediterranean strains while being distant from the currently applied vaccines, thus stressing once more the necessity to evaluate aMPV diffusion and evolution
Lupini C. - One of the best experts on this subject based on the ideXlab platform.
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What is new on molecular characteristics of Avian Metapneumovirus strains circulating in Europe?
'Wiley', 2020Co-Authors: Mescolini G., Lupini C., Cecchinato M., Franzo G, Quaglia G., Legnardi M., Tucciarone C., Blanco A., Biarnes M.Abstract:In the present study, one hundred and sixteen partial G gene sequences of Avian Metapneumovirus (aMPV) subtype B, obtained during routine diagnostics in different European Countries in the last few years (2014\u20132019), were analysed by sequence and phylogenetic analyses in order to draw an updated picture of the molecular characteristics of circulating strains. Nucleotide sequences were compared with other sequences of European and non-European aMPV-Bs collected prior to that period or retrieved from GenBank. Phylogenetic relationships among the aMPV-B strains, reconstructed using the maximum likelihood method implemented in MEGA X, demonstrated that aMPV-B has evolved in Europe from its first appearance, frequently displaying a clear relation with the geographic area of detection. The 40% of aMPV-B viruses analysed were classified as vaccine-derived strains, being phylogenetically related, and showing high nucleotide identity with live commercial vaccine strains licensed in Europe. The remaining 60% were classified as field strains since they clustered separately and showed a low nucleotide identity with vaccines and vaccine-derived strains. The phylogenetic tree showed that the virus has continued to evolve from its first appearance in the \u201980s since more recently detected strains belonged to clades phylogenetically distant from the older strains. Unlike vaccine-derived strains, field strains tended to cluster according to their geographic origin and irrespective of the host species where the viruses had been detected. In conclusion, the molecular characterization of aMPV-B and the differentiation between vaccines and field strains through G gene sequence analysis can be a useful tool towards correct diagnosis and should be routinely applied in order to better address the control strategies
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Rapid detection of subtype B Avian Metapneumoviruses using RT-PCR restriction endonuclease digestion indicates field circulation of vaccine derived viruses in older turkeys
'Informa UK Limited', 2014Co-Authors: Lupini C., Cecchinato Mattia, Pesente P., Rossi G., Naylor C. J., Giovanardi D., Catelli E.Abstract:Live vaccines predominantly control Avian Metapneumovirus (AMPV) infection in the poultry industry but vaccine virus can be found for extended periods after application. The most frequently used AMPV vaccine in Italy, VCO3 subtype B, was shown to contain a unique Tru9I restriction endonuclease (RE) site within the amplicon resulting from of a commonly used AMPV diagnostic RT-nested PCR. Analysis of European and database logged subtype B AMPV sequences confirmed the sequence only occurred in the VC03 vaccine. A subsequent RT-PCR-RE study of field samples, collected from turkeys between 2007 and 2012, detected subtype B vaccine derived strains in twelve of ninety tested samples, collected from birds below 12 weeks of age
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AN UPDATE ON THE EPIDEMIOLOGY OF Avian Metapneumovirus IN ITALY
2014Co-Authors: Cecchinato Mattia, Lupini C., Franzo Giovanni, Martini Marco, Naylor C. J., Drigo Michele, Laconi A., Morandini E., Catelli E.Abstract:A molecular survey on Avian Metapneumovirus (aMPV) diffusion was performed from 2011 to 2013 in 122 turkey and 48 broiler farms, located in a densely populated poultry area of Northern Italy. Turkeys were all vaccinated at 1 day of age in the hatchery. aMPV was detected using RTnested PCR or qRT-PCR; both tests are able to detect and differentiate aMPV subtypes A and B. All samples but one resulted positive for aMPV subtype B confirming the high prevalence of this subtype in Italy. The majority of aMPV detections were of field origin, circulating mainly in 9 to 12-week-old turkeys and 5 to 7 week-old broilers, showing respiratory signs. The reasons for vaccine failure could be due to field virus changes occurred in key antigenic regions, which allow virus replication and disease in well-vaccinated birds. Strains of vaccine origin were detected in turkeys with a high prevalence during the first few weeks after vaccination with aMPV live vaccines. This confirmed the pattern previously seen where vaccine viruses were shown to persist on farm for 4-5 weeks. Uniquely in this study, vaccine derived strains were detected in older turkeys of up to 84 days of age. Moreover, sequence analysis of F and G protein genes of selected strains was performed
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LONGITUDINAL FIELD STUDIES OF Avian Metapneumovirus AND TURKEY HEMORRHAGIC ENTERITIS VIRUS IN TURKEYS SUFFERING FROM COLIBACILLOSIS-ASSOCIATED MORTALITY
place:Giessen, 2014Co-Authors: Giovanardi D., Pesente P., Lupini C., Rossi G., Elena CatelliAbstract:This study evaluated if, in field conditions, the infection with Avian Metapneumovirus (AMPV) and/or Turkey Hemorrhagic Enteritis Virus (THEV) was significant for the induction of episodes of colibacillosis in AMPV and THEV vaccinated turkeys. Colibacillosis-associated mortality was recorded and longitudinal virological studies performed in three consecutive turkey flocks reared in the same farm. AMPV and THEV diagnostic swabs and blood samples were made once a week up to 14 weeks of age. Swabs were processed by molecular techniques, and antibody titres were evaluated by ELISA. When AMPV of subtype B was detected, samples were subjected to a restriction endonuclease digestion protocol to discriminate between field and vaccine strains. Field strains were detected in all flocks at different ages of life, always associated with respiratory signs and increase of colibacillosis-associated mortality. THEV has been consistently detected in all flocks since the 9th week of age. Vaccination with a single dose of the THEV commercial inactivated vaccine available in Italy seems do not protect the birds from the infection. Sequence comparison of the hexon protein of one of the THEV strains detected, and strains isolated worldwide, revealed high similarity between them. These results are consistent with the notion that the hexon protein, being the major antigenic component of the virus, is highly conserved between the strains. Results showed that field AMPV infection is correlated to colibacillosis-associated mortality. Less clear appears the role of THEV because the endemicity of AMPV makes difficult to evaluate its role in predisposing colibacillosis in absence of AMPV
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First evidence of Avian Metapneumovirus subtype A infection in turkeys in Egypt.
'Springer Science and Business Media LLC', 2014Co-Authors: Aa ,abdel Azeem, Lupini C., Catelli E., Franzo Giovanni, Martini Marco, Drigo Michele, Dalle Zotte Antonella, Cecchinato MattiaAbstract:Although Avian Metapneumovirus (aMPV) infection has been reported in most regions of the world, to date, only subtype B has been detected in Egypt. At the end of November 2013, dry oropharyngeal swabs were collected during an outbreak of respiratory diseases in a free-range, multi-age turkey dealer farm in Northern Upper Egypt. The clinical signs that appeared when turkeys were 3 weeks-old were characterized by ocular and nasal discharge and swelling of sinuses. aMPV of subtype A was detected by real-time reverse transcription-polymerase chain reaction. In order to confirm the results and obtain more information on the molecular characteristics of the virus, F and G protein genes were partially sequenced and compared with previously published sequences deposited in GenBank by using BLAST. Subtype of the strain was confirmed by sequencing of partial F and G protein genes. The highest percentages of identity were observed when G sequence of the Egyptian strain was compared with the sequence of an aMPV-A isolated in Nigeria (96.4 %) and when the F sequence was compared with strains isolated respectively in Italy and in UK (97.1 %). Moreover, the alignment of the sequences with commercial subtype A vaccine or vaccine-derived strains showed differences in the Egyptian strain that indicate its probable field origin. The detection of aMPV in the investigated turkey flock highlights some relevant epidemiological issues regarding the role that multi-age farms and dealers may play in perpetuating aMPV infection within and among farms. To our knowledge, this is the first report of aMPV subtype A in Egypt
Cw Arns - One of the best experts on this subject based on the ideXlab platform.
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Production of monoclonal antibodies for Avian Metapneumovirus (SHS-BR-121) isolated in Brazil
Fundação APINCO de Ciência e Tecnologia Avícolas, 2015Co-Authors: Lt Coswig, Stach-machado Dr, Cw ArnsAbstract:Avian Metapneumovirus (aMPV), also called Turkey Rhinotracheitis Virus (TRTV), is an upper respiratory tract infection of turkeys, chickens and other Avian species. Five monoclonal antibodies (MAbs) were created against the Brazilian isolate (SHS-BR-121) of aMPV, MAbs 1A5B8; 1C1C4; 2C2E9 and 2A4C3 of IgG1 and MAb 1C1F8 of IgG2a. Four Mabs (1A5B8; 1C1C4; 2C2E9 and 2A4C3) showed neutralizing activity and three (1A5B8; 1C1C4 and 2A4C3) inhibited cellular fusion in vitro. These MAbs were used to investigate antigenic relationship among three strains (SHS-BR-121, STG 854/88 and TRT 1439/91) of aMPV subtypes A and B using cross-neutralization test. The results confirm that the monoclonal antibodies described can be used as a valuable tool in the epizootiological and serological studies, and also for the specific diagnosis of the subtypes in the infection for Avian Metapneumovirus
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Production of monoclonal antibodies for Avian Metapneumovirus (SHS-BR-121) isolated in Brazil
Fundação APINCO de Ciência e Tecnologia Avícolas, 2015Co-Authors: Lt Coswig, Stach-machado Dr, Cw ArnsAbstract:Avian Metapneumovirus (aMPV), also called Turkey Rhinotracheitis Virus (TRTV), is an upper respiratory tract infection of turkeys, chickens and other Avian species. Five monoclonal antibodies (MAbs) were created against the Brazilian isolate (SHS-BR-121) of aMPV, MAbs 1A5B8; 1C1C4; 2C2E9 and 2A4C3 of IgG1 and MAb 1C1F8 of IgG2a. Four Mabs (1A5B8; 1C1C4; 2C2E9 and 2A4C3) showed neutralizing activity and three (1A5B8; 1C1C4 and 2A4C3) inhibited cellular fusion in vitro. These MAbs were used to investigate antigenic relationship among three strains (SHS-BR-121, STG 854/88 and TRT 1439/91) of aMPV subtypes A and B using cross-neutralization test. The results confirm that the monoclonal antibodies described can be used as a valuable tool in the epizootiological and serological studies, and also for the specific diagnosis of the subtypes in the infection for Avian Metapneumovirus.255258Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
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Inhibition of Avian Metapneumovirus (AMPV) replication by RNA interference targeting nucleoprotein gene (N) in cultured cells
'Elsevier BV', 2015Co-Authors: Hl Ferreira, Spilki Fr, Rs ,de Almeida, Santos Mmab, Cw ArnsAbstract:Avian Metapneumovirus (AMPV) is the primary causative agent of severe rhinotracheitis in turkeys. It is associated with swollen head syndrome in chickens and is the source of significant economic losses to animal food production. In this study, we designed specific short interfering RNA (siRNA) targeting the AMPV nucleoprotein (N) and fusion (F) genes. Three days post-virus infection, virus titration, real time RT-PCR, and RT-PCR assays were performed to verify the effect of siRNA in AMPV replication. A marked decrease in virus titers from transfected CER cells treated with siRNA/N was observed. Also, the production of N, F, and G mRNAs in AMPV was decreased. Results indicate that N-specific siRNA can inhibit virus replication. In future studies, a combination of siRNAs targeting the RNA polymerase complex may be used as a tool to study AMPV replication and/or antiviral therapy. (c) 2006 Elsevier B.V. All rights reserved.741778
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Propagation of Avian Metapneumovirus subtypes A and B using chicken embryo related and other cell systems
'Elsevier BV', 2015Co-Authors: Lt Coswig, Hl Ferreira, Mb ,dos Santos, Hm Hafez, Cw ArnsAbstract:Primary isolation of Avian Metapneumovirus (aMPV) is carried out using tracheal organ culture (TOC) or chicken embryonated eggs with subsequent adaptation in chicken embryo fibroblasts (CEF) or Vero cultures. This study was conducted to evaluate six different cell lines and two Avian culture systems for the propagation of aMPV subtypes A and B. The chicken embryo related (CER) cells were used successfully for primary isolation. In addition to Vero and baby hamster kidney (BHK-21) cells, CER cells were also shown to be the most appropriate for propagation of aMPV considering high titres. Propagation of A and B subtypes in CEF and TOC remained efficient after the primary isolation and several passages of viruses in the CER cell line. The growth curves were created using CER, Vero and BHK-21 cell lines. Compared with growth, both yielded higher titres in CER cells during the first 30 h after infection, but no significant difference was observed in the results obtained from CER and Vero cells. This data show that CER cells are adequate for aMPV subtypes A and B propagation, giving similar results to Vero cells. (C) 2010 Elsevier B.V. All rights reserved.16711
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Comparative evaluation of conventional RT-PCR and real-time RT-PCR (RRT-PCR) for detection of Avian Metapneumovirus subtype A
Univ Federal Santa Maria, 2015Co-Authors: Hl Ferreira, Rs ,de Almeida, Spilki Fr, Dos Santos Mmab, Cw ArnsAbstract:Avian Metapneumovirus (AMPV) belongs to Metapneumovirus genus of Paramyxoviridae family. Virus isolation, serology, and detection of genomic RNA are used as diagnostic methods for AMPV. The aim of the present study was to compare the detection of six subgroup A AMPV isolates (AMPV/A) viral RNA by using different conventional and real time RT-PCR methods. Two new RT-PCR tests and two real time RT-PCR tests, both detecting fusion (F) gene and nucleocapsid (N) gene were compared with an established test for the attachment (G) gene. All the RT-PCR tested assays were able to detect the AMPV/A. The lower detection limits were observed using the N-, F-based RRT-PCR and F-based conventional RT-PCR (10(0.3) to 10(1) TCID(50) mL(-1)). The present study suggests that the conventional F-based RT-PCR presented similar detection limit when compared to N-and F-based RRT-PCR and they can be successfully used for AMPV/A detection
