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1.
Virus Genes ; 60(1): 32-43, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38184501

RESUMO

Fifty-seven Gallid alphaherpesvirus 2 (GaHV-2) isolates, collected during a 30-year period (1990-2019) from commercial poultry flocks affected by Marek's disease (MD), were molecularly characterised. The GaHV-2 meq gene was amplified and sequenced to evaluate the virus virulence, based on the number of PPPPs within the proline-rich repeats (PRRs) of its transactivation domain. The present illustration of virus virulence evaluation on a large scale of field virus isolates by molecular analysis exemplifies the practical benefit and usefulness of the molecular marker in commercial GaVH-2 isolates. The alternative assay of GaVH-2 virulence pathotyping is the classical Gold Standard ADOL method, which is difficult and impossible to employ on a large scale using the Specific Pathogen Free (SPF) chicks of the ADOL strains kept in isolators for two months. The phylogenetic analysis performed in the present study showed that the meq gene amino acid sequences of the 57 Israeli strains divide into 16 phylogenetic branches. The virulence evaluation was performed in comparison with 36 GaHV-2 prototype strains, previously characterised by the in vivo Gold Standard ADOL assay. The results obtained revealed that the GaHV-2 strains circulating in Israel have evolved into a higher virulence potential during the years, as the four-proline stretches number in the meq gene decreased over the investigated period, typically of very virulent virus prototypes. The present study supports the meq gene molecular markers for the assessment of field GaVH-2 strains virulence.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek , Proteínas Oncogênicas Virais , Doenças das Aves Domésticas , Animais , Aves Domésticas , Israel , Virulência/genética , Filogenia , Proteínas Oncogênicas Virais/genética , Herpesvirus Galináceo 2/genética , Galinhas , Prolina/genética
2.
Vet Res Commun ; 47(4): 2307-2313, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37289400

RESUMO

Haemorrhagic enteritis is an economically significant disease reported in the majority of the countries where turkeys are raised intensively; it is caused by Turkey adenovirus 3 (TAdV-3). The aim of this study was to analyse and compare the ORF1 gene 3' region from turkey haemorrhagic enteritis virus (THEV) vaccine-like and field strains in order to develop a molecular diagnostic method to differentiate the strains from each other. Eighty samples were analysed by sequencing and phylogenetic analyses using a new set of polymerase chain reaction (PCR) primers targeting a genomic region spanning the partial ORF1, hyd and partial IVa2 gene sequences. A commercial live vaccine was also included in the analysis. The results showed that 56 of the 80 sequences obtained in this study showed ≥99.8% nucleotide identity with the homologous vaccine strain sequence. Three non-synonymous mutations - ntA1274G (aaI425V), ntA1420C (aaQ473H) and ntG1485A (aaR495Q) - were detected in the THEV field strains but not in the vaccine strain. Phylogenetic analysis confirmed the clustering of the field and vaccine-like strains in different phylogenetic branches. In conclusion, the method employed in this study could be a useful tool towards making a correct diagnosis. The data could contribute to the knowledge of field distribution of THEV strains and increase the limited existing information available on native isolates around the world.


Assuntos
Enterite , Doenças das Aves Domésticas , Siadenovirus , Vacinas , Animais , Siadenovirus/genética , Filogenia , Enterite/veterinária , Perus
3.
Vet Ital ; 58(1): 117-124, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36398672

RESUMO

The present study investigates an outbreak of classical Marek's disease (MD) in backyard Cochin chickens reared for hobby in Italy. Examined chickens showed spastic paralysis of the legs and at necropsy, enlargement and discoloration of the peripheral nerves and plexuses that matched microscopic A­ and B­ type MD lesions. Molecular analysis of the meq gene of the detected Gallid alphaherpesvirus 2 (GaHV­2) strain, showed typical markers of low virulence and the strain shared the entire meq gene sequence with strains circulating in Italian backyard chickens. Furthermore, the haplotype B19 of the major histocompatibility complex (MHC) was defined in the affected chickens, showing that the birds possessed a genetic profile of high susceptibility to MD, allowing the appearance of a classical nervous clinical form after infection with an apparently low pathogenicity GaHV­2 strain. Trade of live ornamental purebred chickens occurs frequently between hobby farmers and biosecurity practices, such as quarantine periods, should be applied to avoid the introduction of infected animals. Veterinarians should raise awareness of this issue and promote the use of vaccines against MD.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek , Doenças das Aves Domésticas , Animais , Doença de Marek/epidemiologia , Galinhas , Herpesvirus Galináceo 2/genética , Virulência/genética
4.
Front Vet Sci ; 9: 873163, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35812862

RESUMO

Marek's disease, an economically important disease of chickens caused by virulent serotype 1 strains of the Mardivirus Marek's disease virus (MDV-1), is effectively controlled in the field by live attenuated vaccine viruses including herpesvirus of turkeys (HVT)-both conventional HVT (strain FC126) and, in recent years, recombinant HVT viruses carrying foreign genes from other avian viruses to protect against both Marek's disease and other avian viral diseases. Testing to monitor and confirm successful vaccination is important, but any such test must differentiate HVT from MDV-1 and MDV-2, as vaccination does not prevent infection with these serotypes. End-point and real-time PCR tests are widely used to detect and differentiate HVT, MDV-1 and MDV-2 but require expensive specialist laboratory equipment and trained operators. Here, we developed and validated two tube-based loop-mediated isothermal amplification tests coupled with detection by lateral flow device readout (LAMP-LFD): an HVT-specific test to detect both conventional and recombinant HVT strains, and a second test using novel LAMP primers to specifically detect the Vaxxitek® recombinant HVT. Specificity was confirmed using DNA extracted from virus-infected cultured cells, and limit of detection was determined using plasmid DNA carrying either the HVT or Vaxxitek® genome. The LAMP-LFD tests accurately detected all HVT vaccines, or Vaxxitek® only, in crude DNA as well as purified DNA extracted from field samples of organs, feathers, or poultry house dust that were confirmed positive for HVT by real-time PCR. These LAMP-LFD tests have potential for specific, rapid, simple, and inexpensive detection of HVT vaccines in the field.

5.
Avian Pathol ; 51(3): 283-290, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35261311

RESUMO

Avian metapneumovirus (aMPV) economically affects the global poultry industry causing respiratory and reproductive disorders. Considering the paucity of data on aMPV occurrence in European free-ranging avifauna, a molecular survey was conducted on wild birds of 23 species belonging to the orders Anseriformes, Charadriiformes or Passeriformes, captured alive and sampled in Northeast Italy as part of the national avian influenza virus (AIV) surveillance activities. A total of 492 oropharyngeal swabs, collected from 2007-2010, all AIV-negative, were screened from aMPV by subtype-specific qRT-PCR. An aMPV-C strain, named aMPV/C/IT/Wigeon/758/07, was found in a wintering young Eurasian wigeon (Mareca penelope) sampled in November 2007. The matrix, fusion, and attachment glycoprotein genes of the detected strain were subsequently amplified by specific independent RT-PCRs, then sequenced, and compared in a phylogenetic framework with known aMPV homologous sequences retrieved from GenBank. Close genetic relationships were found between the aMPV/C/IT/Wigeon/758/07 strain and subtype C Eurasian lineage strains isolated in the late 1990s in French domestic ducks, suggesting epidemiological links. Eurasian wigeons are medium/long-range migrant dabbling ducks that move along the Black Sea/Mediterranean flyway; our finding might, therefore, be related to migratory bridges between countries. To our knowledge, this is the first molecular evidence of the occurrence of aMPV subtype C in Italy and backdates the aMPV-C circulation to 2007. Moreover, the results suggest the susceptibility of Eurasian wigeons to aMPV. Broader investigations are needed to assess the role of wild ducks and the significance of the wildfowl/poultry interface in aMPV-C epidemiology.RESEARCH HIGHLIGHTSWild birds live-captured in Italy were tested for aMPV detection and characterization.aMPV-C Eurasian lineage was found for the first time in a wintering Eurasian wigeon.Migratory birds could be involved in the aMPV epidemiology.


Assuntos
Vírus da Influenza A , Influenza Aviária , Metapneumovirus , Doenças das Aves Domésticas , Animais , Anticorpos Antivirais , Aves , Patos , Influenza Aviária/epidemiologia , Filogenia
6.
Animals (Basel) ; 13(1)2022 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-36611670

RESUMO

In recent years, the impact of respiratory disease resulting from Avian Metapneumovirus (aMPV) infection has been generally rising in the broiler industry in Europe. In this context, in order to investigate aMPV contribution to the clinical picture and the potential benefits of diversified vaccination strategies compared to nonvaccination policies, a longitudinal monitoring was performed, also evaluating Infectious Bronchitis Virus (IBV) presence. Broiler flocks located in Western France, where aMPV has already proven to be a health and productivity issue, were screened by RT-PCR on rhino-pharyngeal swabs, and the viruses were genetically characterized by sequence analysis. For a more comprehensive picture of aMPV molecular epidemiology and evolution in France, aMPV subtype B strains detected from 1985 to 1998 were sequenced and included in the analysis. The survey confirmed the detection of aMPV subtype B in commercial broiler flocks in France, together with a certain heterogeneity demonstrated by the circulation of more recent and historical French field strains. No IBV field strains were detected. The implementation and evaluation of different management choices and vaccine strategies suggests once again that immunization does not prevent infection but contributes greatly to the containment of the clinical manifestations.

7.
Animals (Basel) ; 11(4)2021 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-33801597

RESUMO

Chicken infectious anemia virus (CIAV) is a pathogen of chickens associated with immunosuppression and with a disease named chicken infectious anemia. The present survey reports an epidemiological study on CIAV distribution in Italian broiler, broiler breeder and backyard chicken flocks. Twenty-five strains were detected by a specifically developed nested PCR protocol, and molecularly characterized by partial VP1 gene or complete genome sequencing. Viral DNA amplification was successfully obtained from non-invasive samples such as feathers and environmental dust. Sequence and phylogenetic analysis showed the circulation of field or potentially vaccine-derived strains with heterogeneous sequences clustered into genogroups II, IIIa, and IIIb. Marker genome positions, reported to be correlated with CIAV virulence, were evaluated in field strains. In conclusion, this is the first survey focused on the molecular characteristics of Italian CIAVs, which have proved to be highly heterogeneous, implementing at the same time a distribution map of field viruses worldwide.

8.
Transbound Emerg Dis ; 68(3): 1314-1322, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32794302

RESUMO

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 (2014-2019), 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 '80s 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.


Assuntos
Galinhas , Glicoproteínas/genética , Metapneumovirus/genética , Infecções por Paramyxoviridae/veterinária , Doenças das Aves Domésticas/virologia , Perus , Proteínas Virais/genética , Animais , Europa (Continente) , Galliformes , Glicoproteínas/metabolismo , Metapneumovirus/classificação , Infecções por Paramyxoviridae/virologia , Filogenia , Proteínas Virais/metabolismo
9.
Parasit Vectors ; 13(1): 513, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33054854

RESUMO

BACKGROUND: The poultry red mite Dermanyssus gallinae (De Geer, 1778) is a major ectoparasite of poultry. Infestations are found in most laying hen farms in Europe, and breeder flocks have also been reported to be affected. Mite infestation has detrimental effects on animal welfare, it causes significant economic losses, and, additionally, D. gallinae is often considered as a vector for pathogens. Despite suspicion of a close relationship between the poultry red mite and Salmonella enterica enterica serovar Gallinarum biovar Gallinarum (serovar Gallinarum), the causative agent of fowl typhoid disease (FT), there has been no definitive proof of mite-mediated transmission. Therefore, an investigation was conducted to determine if D. gallinae-mediated transmission of serovar Gallinarum could be demonstrated among four different hen groups. METHODS: Two groups of 8 hens (A and B) were experimentally infected with serovar Gallinarum in two isolators. After 7 days, when birds showed signs of FT, about 25,000 mites were introduced. After 3 days, mites were harvested and used to infest two other hen groups of 8 (C and D), in two separate isolators. The health status of hens was constantly monitored; detection and quantification of serovar Gallinarum were performed by PCR and qPCR from mites and organs of dead hens. The maximum likelihood estimation of the infection rate and mite vectorial capacity were calculated. RESULTS: Clinical disease was observed in groups infected with serovar Gallinarum (A and B) and in hens of groups C and D infested with mites harvested from the isolators containing groups A and B. In all four groups, serovar Gallinarum was detected from liver, spleen, ovary, and cecum of hens, thus confirming the diagnosis of FT. Mite analysis demonstrated the presence of the pathogen, with an estimated infection rate ranging between 13.72 and 55.21 infected per thousand mites. Vectorial capacity was estimated to be 73.79. CONCLUSIONS: Mites harvested from birds infected with serovar Gallinarum were shown to carry the mite, and then to transfer serovar Gallinarum to isolated groups of pathogen-free birds that subsequently showed signs of FT. Mite vectorial capacity was high, demonstrating that D. gallinae should be considered an effective vector of FT.


Assuntos
Vetores Aracnídeos/microbiologia , Galinhas/parasitologia , Infestações por Ácaros/veterinária , Ácaros/microbiologia , Doenças das Aves Domésticas/parasitologia , Salmonella enterica/imunologia , Febre Tifoide/veterinária , Animais , Galinhas/microbiologia , Feminino , Infestações por Ácaros/parasitologia , Doenças das Aves Domésticas/microbiologia , Salmonella enterica/genética , Salmonella enterica/isolamento & purificação , Sorogrupo , Febre Tifoide/microbiologia
10.
Poult Sci ; 99(9): 4351-4359, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32867979

RESUMO

The vaccines currently available to control infectious bursal disease (IBD) include live-attenuated and inactivated vaccines, immune-complex vaccines, and vaccines consisting of viral constructs of herpesvirus of turkeys genetically engineered to express VP2 surface protein. To evaluate the impact of vaccines on the chicken immune system, 2 animal trials were performed in specific pathogen-free broiler chickens. In trial 1, birds were either vaccinated when they are one-day old with a dual recombinant herpes virus of turkey construct vaccine, expressing VP2 protein of (IBDV) and F protein of Newcastle disease virus, or an immune-complex IBDV vaccine or birds were not vaccinated. At 14, 28, and 35 D, the bursa of Fabricius was collected for bursa:body weight (B:BW) ratio calculation. In trial 2, birds were vaccinated when they were 1-day old according to the same protocol as trial 1, but at day 14, all groups also received a live infectious bronchitis (IB) vaccine. At 0, 7, 14, 21, and 28 days after IB vaccination, birds were tested by ELISA for IB serology and, soon after the last blood sampling, they were euthanized for collection of Harderian glands, trachea, and spleen and testing by flow cytometry for characterization of mononuclear cells. The immune-complex vaccine groups showed significantly lower B:BW ratio, lower IBV antibody titers, and higher mean percentage of CD8+ T cells in the spleen, trachea, and Harderian glands than those in the other experimental groups. The results of the in vivo trials coupled with a depth analysis of the repertoire of parameters involved in the immune response to IBD and IB vaccinations show one vaccine may influence the immune response of other vaccines included in the vaccination program.


Assuntos
Infecções por Birnaviridae/veterinária , Doenças das Aves Domésticas/imunologia , Vacinas Virais/imunologia , Animais , Infecções por Birnaviridae/imunologia , Bolsa de Fabricius/patologia , Galinhas , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/veterinária , Vírus da Bronquite Infecciosa/imunologia , Vírus da Doença Infecciosa da Bursa/imunologia , Vírus da Doença de Newcastle/imunologia , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/virologia , Organismos Livres de Patógenos Específicos , Vacinação/veterinária , Vacinas Atenuadas/imunologia
11.
Vet Res ; 51(1): 88, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32641149

RESUMO

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 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.


Assuntos
Galinhas , Metapneumovirus/classificação , Infecções por Paramyxoviridae/veterinária , Doenças das Aves Domésticas/virologia , Perus , Animais , Europa (Continente)/epidemiologia , Evolução Molecular , Infecções por Paramyxoviridae/classificação , Infecções por Paramyxoviridae/transmissão , Infecções por Paramyxoviridae/virologia , Doenças das Aves Domésticas/classificação , Doenças das Aves Domésticas/epidemiologia
12.
Poult Sci ; 99(2): 719-724, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32029157

RESUMO

Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) represent the most important avian Mycoplasma species in the poultry industry, causing considerable economic losses. In Italy, the presence of MG or MS has been investigated especially in commercial poultry farms. To our knowledge, no systematic investigations on MG or MS presence using highly specific diagnostic assays have been performed in backyard poultry. The aim of this study was to detect and molecularly characterize MG and MS strains in 11 backyard poultry flocks located in different regions of Italy. Tracheal swabs were collected and DNA was extracted. For MS, a PCR targeting a vlhA gene fragment was performed, and typing and subtyping was attempted. The presence of MG was investigated by a screening PCR, then MG typing by gene-targeted sequencing (GTS). All the amplicons were sequenced, then MG and MS dendrograms were constructed. All the flocks examined resulted Mycoplasma positive: 5 out of 11 (45.45%) were MG and MS positive, 3 (27.27%) were MG positive, and the remaining 3 (27.27%) were MS positive. The MS detections were assigned to types C, D, and F. All strains of type D belonged to subtype D1 and 2 unknown subtypes were identified. A MS sequence showed peculiar characteristics, which did not allow assignment to a known MS type or subtype. MG GTS analysis identified 6 MG strains belonging to 5 subclusters circulating in Italian backyards chicken flocks. The results of this study provide evidence of a risk for commercial poultry farms, especially in areas where backyard and commercial farms are close, suggesting the implementation of biosecurity measures.


Assuntos
Galinhas , Infecções por Mycoplasma/veterinária , Mycoplasma gallisepticum/isolamento & purificação , Mycoplasma synoviae/isolamento & purificação , Doenças das Aves Domésticas/microbiologia , Animais , Itália , Infecções por Mycoplasma/microbiologia , Reação em Cadeia da Polimerase/veterinária
13.
Transbound Emerg Dis ; 67(1): 98-107, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31411371

RESUMO

Marek's disease (MD) is a lymphoproliferative disease important to the poultry industry worldwide; it is caused by Gallid alphaherpesvirus 2 (GaHV-2). The virulence of GaHV-2 isolates has shifted over the years from mild to virulent, very virulent and very virulent +. Nowadays the disease is controlled by vaccination, but field strains of increased virulence are emerging worldwide. Economic losses due to MD are mostly associated with its acute form, characterized by visceral lymphomas. The present study aimed to molecularly classify a group of 13 GaHV-2 strains detected in vaccinated Italian commercial chicken flocks during acute MD outbreaks, and to scrutinize the ability of predicting GaHV-2 virulence, according to the meq gene sequence. The full-length meq genes were amplified, and the obtained amino acid (aa) sequences were analysed, focusing mainly on the number of stretches of four proline molecules (PPPP) within the transactivation domain. Phylogenetic analysis was carried out with the Maximum Likelihood method using the obtained aa sequences, and the sequences of Italian strains detected in backyard flocks and of selected strains retrieved from GenBank. All the analysed strains showed 100% sequence identity in the meq gene, which encodes a Meq protein of 339 aa. The Meq protein includes four PPPP motifs in the transactivation domain and an interruption of a PPPP motif due to a proline-to-serine substitution at position 218. These features are typically encountered in highly virulent isolates. Phylogenetic analysis revealed that the analysed strains belonged to a cluster that includes high-virulence GaHV-2 strains detected in Italian backyard flocks and a hypervirulent Polish strain. Our results support the hypothesis that the virulence of field isolates can be suggested by meq aa sequence analysis.


Assuntos
Galinhas/virologia , Herpesvirus Galináceo 2/classificação , Doença de Marek/virologia , Proteínas Oncogênicas Virais/genética , Doenças das Aves Domésticas/virologia , Sequência de Aminoácidos , Animais , Herpesvirus Galináceo 2/genética , Herpesvirus Galináceo 2/isolamento & purificação , Itália/epidemiologia , Doença de Marek/epidemiologia , Filogenia , Doenças das Aves Domésticas/epidemiologia , Análise de Sequência de Proteína/veterinária , Virulência/genética
14.
Transbound Emerg Dis ; 67(2): 1025-1031, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31715072

RESUMO

Recently, a new genotype of infectious bursal disease virus (IBDV), named ITA, was detected in IBD-vaccinated Italian broilers. Genome characterization revealed ITA to be a genetically different IBDV, belonging to genogroup 6 according to a recently proposed IBDV classification. The currently available clinical data do not allow any definition of the degree of pathogenicity of the ITA-IBDV isolates. In the present study, a pathogenicity trial was conducted by the oral inoculation of specific-pathogen-free (SPF) chickens. Birds were housed in poultry isolators and inoculated at 35 days of age with an ITA-IBDV isolate (35 birds) or a strain belonging to the G1a genogroup as a comparison (35 birds). Control birds (25 birds) were contextually mock-inoculated with sterile water. Birds were observed daily for clinical signs and at 0, 7, 14, 21 and 28 days post-inoculation (dpi) were bled for IBDV antibody detection. At 2, 4, 7, 14, 21 and 28 dpi, five birds from each of the inoculated groups, and three from the control group, were euthanized and subjected to a post-mortem examination; the bursa:body weight and thymus:body weight ratios were calculated. Microscopic lesions of the bursa and thymus were scored on the basis of lymphoid necrosis and/or depletion or cortex atrophy, respectively. Both viruses induced a subclinical course of disease, as neither clinical signs nor mortality were recorded during the study, even in the presence of typical IBDV gross and microscopic lesions. Bursal damage, measured by the bursa:body weight ratio, was more noticeable and precocious after ITA-IBDV inoculation. Histopathology scores of the bursa, indicative of rapid lymphoid depletion, confirmed the aggressiveness of the ITA-IBDV strain in this organ. This study showed that, although the ITA-IBDV strain tested causes infection with a subclinical course, it induces severe damage to lymphoid tissues. Therefore, its circulation in birds might be a threat for the poultry industry and may jeopardize the success of the production cycle.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Birnaviridae/veterinária , Vírus da Doença Infecciosa da Bursa/patogenicidade , Doenças das Aves Domésticas/virologia , Vacinação/veterinária , Animais , Infecções por Birnaviridae/virologia , Bolsa de Fabricius/patologia , Bolsa de Fabricius/virologia , Galinhas , Genótipo , Vírus da Doença Infecciosa da Bursa/genética , Vírus da Doença Infecciosa da Bursa/isolamento & purificação , Itália/epidemiologia , Tecido Linfoide/patologia , Tecido Linfoide/virologia , Organismos Livres de Patógenos Específicos , Virulência
15.
Avian Pathol ; 49(2): 202-207, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31702386

RESUMO

Marek's disease (MD) is a lymphoproliferative disease caused by Gallid alphaherpesvirus 2 (GaHV-2), which primarily affects chickens. However, the virus is also able to induce tumours in turkeys, albeit less frequently than in chickens. This study reports the molecular characterization of a GaHV-2 strain detected in a flock of Italian meat-type turkeys exhibiting visceral lymphomas. Sequencing and phylogenetic analysis of the meq gene revealed that the turkey GaHV-2 has molecular features of high virulence and genetic similarity with GaHV-2 strains recently detected in Italian commercial and backyard chickens. GaHV-2 is ubiquitous among chickens despite vaccination, and chicken-to-turkey transmission is hypothesized due to the presence of broilers in neighbouring pens.RESEARCH HIGHLIGHTS A GaHV-2 strain from Italian turkeys was molecularly characterized.The turkey strain presented molecular characteristics of high virulence in its meq gene.The turkey strain was closely related to previously detected chicken strains.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek/virologia , Neoplasias/veterinária , Perus , Animais , Regulação Viral da Expressão Gênica , Herpesvirus Galináceo 2/genética , Doença de Marek/patologia , Neoplasias/virologia , Proteínas Oncogênicas Virais/isolamento & purificação , Filogenia , Reação em Cadeia da Polimerase/veterinária , Doenças das Aves Domésticas/virologia
16.
Vet Microbiol ; 235: 136-142, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282371

RESUMO

Infectious Bursal Disease Virus (IBDV) of the ITA genotype (G6) was shown to have peculiar molecular characteristics and, despite a subclinical course, aggressiveness towards lymphoid tissues after experimental infection of specific-pathogen-free (SPF) chickens. The aim of the present study was to evaluate and compare with a Classical IBDV strain, ITA IBDV distribution and persistence in various tissues (bursa of Fabricious, spleen, thymus, bone marrow, caecal tonsils, Harderian gland, kidney, liver and proventriculus), its cloacal shedding and the involvement of gut TLR-3 in duodenum tissues. The 35-day-old SPF chickens were experimentally infected and sampled up to 28 days post infection (dpi) for IBDV detection and TLR-3 quantification by qRT-PCR. The ITA IBDV strain was detected in lymphoid and most non-lymphoid tissues up to the end of the trial, with higher loads compared to the Classical IBDV. Most of those differences were found during the first 2 weeks post-infection. Notably, bone marrow and caecal tonsils presented higher viral loads until 28 dpi, allowing to speculate that these organs may serve as non-bursal lymphoid tissues supporting virus replication. Differences in relative TLR-3 gene expression between ITA IBDV-infected birds and Classical-IBDV infected ones were observed at 4, 14 and 21 dpi, being initially higher in Classical group and later in ITA group. Our results provide new insights into IBDV pathogenesis showing that IBDV of ITA genotype leads to a high and persistent viral load in lymphoid tissues and to a delayed antiviral response.


Assuntos
Infecções por Birnaviridae/veterinária , Vírus da Doença Infecciosa da Bursa/genética , Tecido Linfoide/virologia , Doenças das Aves Domésticas/imunologia , Carga Viral , Animais , Infecções por Birnaviridae/imunologia , Medula Óssea/patologia , Medula Óssea/virologia , Galinhas , Ensaio de Imunoadsorção Enzimática , Genótipo , Vírus da Doença Infecciosa da Bursa/patogenicidade , Tonsila Palatina/virologia , Doenças das Aves Domésticas/virologia , Organismos Livres de Patógenos Específicos , Receptor 3 Toll-Like/genética , Replicação Viral
17.
Poult Sci ; 98(8): 3130-3137, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30850833

RESUMO

Marek's disease (MD) is an important lymphoproliferative disease of chickens, caused by Gallid alphaherpesvirus 2 (GaHV-2). Outbreaks are commonly reported in commercial flocks, but also in backyard chickens. Whereas the molecular characteristics of GaHV-2 strains from the commercial poultry sector have been reported, no recent data are available for the rural sector. To fill this gap, 19 GaHV-2 strains detected in 19 Italian backyard chicken flocks during suspected MD outbreaks were molecularly characterized through an analysis of the meq gene, the major GaHV-2 oncogene. The number of four consecutive prolines (PPPP) within the proline-rich repeats of the Meq transactivation domain, the proline content, and the presence of amino acid (aa) substitutions were determined. Phylogenetic analysis was performed using the Maximum Likelihood method. Sequence analysis revealed a heterogeneous population of GaHV-2 strains circulating in Italian backyard flocks. Seven strains, detected from birds affected by classical MD, showed a unique meq isoform of 418 aa with a very high number of PPPP motifs. Molecular and clinical features are suggestive of a low oncogenic potential of these strains. The remaining 12 strains, detected from flocks experiencing acute MD, transient paralysis, or sudden death, had shorter Meq protein isoforms (298 or 339 aa) with a lower number of PPPP motifs and point mutations interrupting PPPP. These features allow us to assert the high virulence of these strains. These findings reveal the circulation of low- and high-virulence GaHV-2 strains in the Italian rural sector.


Assuntos
Herpesvirus Galináceo 2/genética , Doença de Marek/virologia , Proteínas Oncogênicas Virais/genética , Animais , Galinhas , Surtos de Doenças/veterinária , Itália/epidemiologia , Doença de Marek/epidemiologia , Filogenia , Análise de Sequência de DNA/veterinária , Virulência/genética
18.
Poult Sci ; 97(2): 503-509, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29253264

RESUMO

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.


Assuntos
Galinhas , Metapneumovirus/fisiologia , Infecções por Paramyxoviridae/veterinária , Doenças das Aves Domésticas/epidemiologia , Perus , Animais , Itália/epidemiologia , Infecções por Paramyxoviridae/epidemiologia , Infecções por Paramyxoviridae/virologia , Doenças das Aves Domésticas/virologia , Prevalência
19.
Ital J Food Saf ; 6(1): 6228, 2017 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-28462204

RESUMO

The trade in live crustaceans implies keeping these animals alive after capture and/or farming until purchase by the final consumer. Regarding animal welfare, the European Union includes cephalopods in Directive 2010/63/EU on the protection of animals used for scientific purposes, but there are no further regulations on crustaceans in EU legislation. The present study analysed the provisions of Italian municipal regulations on animal welfare applicable to crustaceans. Only 62 of the 110 municipal websites of the provincial capitals reported a regulation safeguarding animal welfare. These regulations contain different rules on: aquaria characteristics (size, volume and shape); management of aquaria; maintenance (preservation and exposure) of live aquatic species; slaughtering and/or suppression of aquatic species and crustaceans; tying of crustacean claws; and crustacean cooking. The analysis on Italian municipal regulations on crustaceans' animal welfare showed that the provisions are vague, lacking uniformity and scientific guidelines.

20.
Ital J Food Saf ; 5(4): 6149, 2016 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-27995099

RESUMO

The aim of this study was to assess whether Döner kebabs sold in Italy comply with legal labelling requirements. A checklist of EU labelling requirements was drawn up and nine labels of Döner kebab marketed in the province of Modena were collected to evaluate the mandatory information laid down in article 9 of Regulation (EU) No 1169/2011 together with the mandatory requirements of Regulation (EC) 853/2004 for meat preparations. The study showed that different additives are commonly used in Döner kebabs, including E 621 (monosodium glutamate). This additive is not included among the ingredients authorized for the meat preparation food category. Eight frozen Döner kebab samples were taken and a visual assessment and a histologic examination were performed to verify potential changes in the meat's inner muscle fibre structure that could allow the product to be considered among meat preparations or meat products. The Döner kebab labels showed several systematically deficient regulatory requirements in both extrinsic defects (not related to food composition) and aspects concerning the protection of consumers' health. Histological examination showed that the tissue was moderately swollen, but the muscle fibre structure was intact. Kebab can be reasonably classified as a meat preparation thereby precluding the use monosodium glutamate (E 621) as an ingredient.

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