RESUMEN
Duck-derived lactic acid bacteria (DDL) are a crucial beneficial bacterium in the intestines, contributing significantly to the health of ducks. However, the mechanism by which these DDL improves the growth performance and meat quality of Muscovy duck is not clear. In this study, A total of 800 male Muscovy ducks, initially weighing 50.15 ± 5.37 g, were randomly allocated into 4 groups, each with 4 replicates, consisting of 50 ducks per replicate. The control group consumed deep well water, while the experimental groups were given water supplemented with 1%, 3%, and 5% DDL (1.59×108 CFU/mL). The study duration was 70 d. The results revealed that Muscovy ducks drinks with the DDL significant reduced the feed conversion ratio (FCR) (P < 0.05) and increased the sweetness and richness of duck meat, among which the 5% drinking group has the most significant difference. Further study finding, the DDL significantly increased the height of villi, the ratio of villi height/crypt depth (V/C) on jejunum and colon, and the ratio of acidic mucus, neutral mucus, and glycogen to tissue area in both the duodenum and ileum of Muscovy ducks, and significantly decreased the tunel positive cells. Moreover, DDL significantly enhanced the abundance of genus beneficial bacterium (Bacillus, lentilactobacillus, Bacterodies, Lactobacillus) on duodenum and ileum. Additionally, drink with the DDL elevated the level of IgG in blood and the immune indices of the thymus and the fabricius bursa (P<0.05). Meanwhile, the meat composition analysis demonstrated that Muscovy duck drinks with the DDL raised the level of the saturated fatty acid rate(C12:0), and polyunsaturated fatty acid (C18:2 n-6 and C20:5 n-3,), and the monounsaturated (C18:1 n-7, and C18:1 n-9). Furthermore, correlation analysis finding that the growth performance of Muscovy ducks was positively correlated with the height of villi, the ratio of villi height/crypt depth (V/C), the abundance of genus beneficial bacterium. And the meat quality of Muscovy ducks has positively correlated with genus beneficial bacterium in intestinal, glutamic acid, saturated fatty acid rate and polyunsaturated fatty acid. This finding suggest DDL is an effective strategy to improve the growth performance and meat quality of Muscovy ducks by gut histomorphology and intestinal microflora.
RESUMEN
Dietary absorption and digestion are influenced by the microbiota, morphology, and digestive enzymes of intestines, and fermentation is a popular and effective technique to enhance animal rearing growth performance. This study aims to explore the pivotal role of Muscovy duck probiotics fermented feedstuff (FF) in altering the growth performance by reshaping gut morphology, microorganisms and metabolism. The findings showed that FF considerably raised the levels of fatty acids (FA) and small peptides (7-19AA) in the diet. Further feeding trial data reveals that FF greatly increased the Muscovy duck average daily gain (ADG) but had no effect on their daily feed intake (DFI), and the FCR significantly dropped (P < 0.05). Additionally, it was evident that FF improved the integrity of the intestinal mucosa in Muscovy duck by increasing villus height, villus height-to-crypt depth ratio, and lowering crypt depth. Then, in comparison to the control group (NC), there was a significant increase in the gene expression of the mucosal tight junction proteins Occludin, Claudin-1, and Zo-1 in the intestine of Muscovy duck. Additionally, there was higher expression of the mucosal transport channels SGLT-1, PepT1, AQP2, AQP3, and AQP10 in the similarly colon site, jejunum, and duodenum. Furthermore, in AB-PAS/PAS-stained duodenum, jejunum, ileum, and similarly colon site, FF markedly increased relative mucus output and goblet cells while decreasing epithelial cell apoptosis. Following 16S sequencing data indicated that the intestinal microbiota was altered and the diversity and richness of gut microbes was greatly enhanced by FF. Particularly, the boost of core probiotics, such as Rothia of duodenum, Limosilactobacillus and Lentilactobacillus of jejunum, Lactococcus and Rothia of ileum, Ligilactobacillus and Entocuccus of similarly colon site, Gallibacterium of caecum. And reduced potentially pathogenic bacteria (Campylobacter, Prevotellaceae, Clostridia-vadinBB60, and Oscillospira). Nontargeted metabolomics assay for intestinal content confirmed an increased organic acids (oxidanesulfonic acid, cholic acid, gallic acid, coumaric acid, pipecollc acid, 13s-hydroxyoctadecadienoic acid) and glycosides metabolites (5-hydroxydantrolene, 3-hydroxyguanfacine glucuronide, acetylleucine, astragalin, xanthosine, taxiphylin, sinapine, denudatine, penylalanyl-tyrosine and phenylalanyl-valine). These findings demonstrated that FF, a viable option to improve Muscovy duck growth performance through reconstructed intestinal morphology, microorganisms, and metabolism, subsequently promoted the gut health and increased diet digestion and absorption. The study that is being presented offers scientific proof that FF might be a useful strategy for improving Muscovy duck growth performance.
Asunto(s)
Alimentación Animal , Dieta , Patos , Microbioma Gastrointestinal , Probióticos , Animales , Patos/crecimiento & desarrollo , Microbioma Gastrointestinal/efectos de los fármacos , Dieta/veterinaria , Alimentación Animal/análisis , Probióticos/administración & dosificación , Probióticos/farmacología , Fermentación , Distribución AleatoriaRESUMEN
A multiplex polymerase chain reaction (PCR) method was developed to detect and distinguish goose parvovirus (GPV), waterfowl reovirus (WRV), and goose astrovirus (GAstV). Three pairs of primers were designed based on conserved regions in the genomic sequences of these enteric viruses and were used to specifically amplify targeted fragments of 493 bp from the viral protein 3 (VP3) gene of GPV, 300 bp from the sigma A-encoding gene of WRV, and 156 bp from the capsid protein-encoding gene of GAstV. The results showed that the primers can specifically amplify target fragments, without any cross-amplification with other viruses, indicating that the method had good specificity. A sensitivity test showed that the detection limit of the multiplex PCR method was 1 × 103 viral copies. A total of 102 field samples from Muscovy ducks with clinically suspected diseases were evaluated using the newly developed multiplex PCR method. The ratio of positive samples to total samples for GPV, WRV, and GAstV was 73.53% (75/102) for multiplex PCR and was 73.53% (75/102) for routine PCR. Seventy-five positive samples were detected by both methods, for a coincidence ratio of 100%. This multiplex PCR method can simultaneously detect GPV, WRV, and GAstV, which are associated with viral enteritis, thereby providing a specific, sensitive, efficient, and accurate new tool for clinical diagnosis and laboratory epidemiological investigations.
Asunto(s)
Infecciones por Parvoviridae , Parvovirus , Enfermedades de las Aves de Corral , Virus ARN , Reoviridae , Animales , Patos , Reacción en Cadena de la Polimerasa Multiplex/métodos , Infecciones por Parvoviridae/diagnóstico , Infecciones por Parvoviridae/veterinaria , Enfermedades de las Aves de Corral/diagnóstico , Reoviridae/genética , Virus ARN/genética , Anticuerpos Antivirales , Gansos , Parvovirus/genéticaRESUMEN
Riemerella anatipestifer (RA) is an important pathogen of waterfowl, with multiple serotypes and a lack of cross-protection between each serotype, which leads to the continued widespread in the world and causing significant economic losses to the duck industry. Thus, prevention and inhibition of RA infection are of great concern. Previous research has established that Lactobacillus plantarum supernatant (LPS) can prevents the pathogenic bacteria infection. However, LPS whether inhibits RA and underlying mechanisms have not yet been clarified. In this study, we investigated the direct and indirect effects of LPS-ZG7 against RA infection in Muscovy ducks. The results demonstrated that LPS-ZG7 prevented RA growth in the presence of pH-neutralized, and the inhibition was relatively stable and unaffected by heat, acid-base and ultraviolet light (UV). Following flow cytometry data found that LPS-ZG7 increased RA membrane permeability and leakage of intracellular molecules. And scanning electron microscopy revealed LPS-ZG7 damaged the RA membrane integrity and leading to RA death. Furthermore, quantitative real time polymerase chain reaction (qPCR) analysis represented that LPS-ZG7 upregulated mucosal tight junction proteins occludin, claudin-1, and Zo-1 in Muscovy ducks, and increasing mucosal transport channels SGLT-1, PepT1, AQP2, AQP3, and AQP10 in duodenum, jejunum, and colon, then decreased the intestinal permeability and intestinal barrier disruption which were caused from RA. From the data, it is apparent that LPS-ZG7 enhanced intestinal mucosal integrity by rising villus height, villus height-to-crypt depth ratio and lower crypt depth. LPS-ZG7 significantly decreased intestinal epithelia cells apoptosis caused by RA invasion, and enhanced intestinal permeability and contribute to barrier dysfunction, ultimately improving intestinal health of host, indirectly leading to reduce diarrhea rate and mortality caused by RA. Overall, this study strengthens the idea that LPS-ZG7 directly inhibited the RA growth by increased RA membrane permeability and damaged the RA membrane integrity, and then indirectly enhanced intestinal mucosal integrity, improved intestinal health of host and mediated intestinal antimicrobial defense.
Asunto(s)
Antiinfecciosos , Infecciones por Flavobacteriaceae , Lactobacillus plantarum , Enfermedades de las Aves de Corral , Riemerella , Animales , Patos/microbiología , Lipopolisacáridos , Acuaporina 2 , Pollos , Infecciones por Flavobacteriaceae/microbiología , Infecciones por Flavobacteriaceae/veterinaria , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/microbiologíaRESUMEN
Duckling short beak and dwarfism syndrome virus (SBDSV), an emerging goose parvovirus, has caused short beak and dwarfism syndrome (SBDS) in Chinese duck flocks since 2015. Presently, there is no commercial vaccine against SBDS. In the present study, a virus-like particle (VLP)-based candidate vaccine was developed against this disease. A baculovirus expression system was used to express the SBDSV VP2 protein in Sf9 cells. Immunofluorescence assay, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting were used to confirm protein expression. Furthermore, transmission electron microscopy was used to observe the formation of VLPs. VLPs were formulated into an oil-adjuvanted maternal vaccine to evaluate humoral responses in breeding ducks via latex particle agglutination inhibition assay (LPAI) and microneutralization assay. The offspring were challenged with SBDSV to test the protective efficacy. A single dose of SBDSV was able to induce the high level of LPAI antibodies in ducks, with LPAI and neutralization peak titres of 4.9 ± 1.20 log2 and 7.1 ± 1.20 log2, respectively, at 4 weeks post-vaccination (wpv). The average LPAI titre of yolk antibodies in duck eggs receiving 2 doses (first and boost doses) of the vaccine was 5.3 ± 1.09 log2 at 4 weeks post-boost. The protective efficacy of the maternal vaccine was 87.5%-100%. These results indicate that SBDSV VLPs can be a promising vaccine candidate for controlling SBDS.
Asunto(s)
Enanismo , Infecciones por Parvoviridae , Enfermedades de las Aves de Corral , Animales , Anticuerpos Antivirales , Pico , Patos , Enanismo/veterinaria , Óvulo , Infecciones por Parvoviridae/veterinaria , Enfermedades de las Aves de Corral/prevención & controlRESUMEN
A new disease designated as Pale liver disease (PLD) has been circulating in Chinese Muscovy duck flocks since 2014, which is characterized by fatigue, diarrhoea, sudden death and acute hepatitis with pale and haemorrhagic liver. In this study, the etiological agents of PLD were isolated, causing a significant cytopathic effect (CPE) by cell rounding. Virus particles were observed by transmission electron microscopic (TEM) observation. The same disease was reproduced by experimental infection with the isolate BG61. The whole genomes of isolates were 43,842 nt in length with a GC content of 47.11%, similar to French Muscovy duck adenovirus strain GR with a GC content of 46.08%. The isolates shared 99.71-99.95% and 93.31-93.33% identity with Chinese Muscovy duck adenovirus isolates and GR strain, respectively. The DNA polymerase gene of all Muscovy duck adenovirus strains formed a separate genetic lineage with 99.55-100% amino acid sequence identity. All Chinese Muscovy duck adenovirus isolates contained two fibre genes. In contrast, only one fibre gene was found in GR, the only representative strain in species Duck aviadenovirus B. Anti-DAdV-2 serum antibodies had a weak neutralizing activity against Chinese Muscovy duck adenovirus isolates. The phylogenetic trees of the complete genome, hexon and fibre proteins revealed that all Muscovy duck adenovirus strains formed a major genetic lineage consisting of two clades. Thus, both GR and Chinese Muscovy duck adenovirus strains were proposed to be included in the same species of Duck aviadenovirus B belonging to the genus Aviadenovirus. The species Duck aviadenovirus B included two serotypes or genotypes, such as GR, which represents the strain of serotype 1 or genotype 1 (DAdV B1) and Chinese Muscovy duck adenovirus strains, which belong to serotype 2 or genotype 2 (DAdV B2).
Asunto(s)
Infecciones por Adenoviridae , Aviadenovirus , Hepatitis , Enfermedades de las Aves de Corral , Infecciones por Adenoviridae/epidemiología , Infecciones por Adenoviridae/veterinaria , Animales , China/epidemiología , Patos , Filogenia , Enfermedades de las Aves de Corral/epidemiologíaRESUMEN
The complete sequence of a reovirus, strain NP03 associated with necrotic focus formation in the liver and spleen of Muscovy ducklings in Fujian Province, China in 2009, was determined and compared with sequences of other waterfowl and chicken-origin avian reoviruses (ARVs). Sequencing of the complete genomes of strain NP03 showed that they consisted of 23,418 bp and were divided into 10 segments, ranging from 1191 bp (S4) to 3959 bp (L1) in length, and all segments contained conserved sequences in the 5' non-coding region (GCUUUU) and 3' non-coding region (UCAUC). Pairwise sequence comparisons demonstrated that NP03 strain showed the highest similarity with novel waterfowl origin reoviruses (WRVs). The genome analysis revealed that the S1 segment of novel WRV is a tricistronic gene, encoding the overlapping open reading frames (ORFs) for p10, p18, and σC, similar to the ARV S1 gene, but distinct from classical WRV S4 genome segment, which contained two overlapping ORFs encoding p10 and σC. Phylogenetic analyses of the nucleotide sequences of all 10 segments revealed that NP03 strain was clustered together with other novel WRVs and were distinct from classical WRVs and chicken-origin ARVs. The analyses also showed possible intra-segmental reassortment events in the segments encoding λA, λB, µB, µNS, σA, and σNS between novel and classical WRVs. Potential recombination events detection in segment L1 suggests that NP03 strain may be recombinants of novel WRVs. Based on our genetic analyses, multiple reassortment events, intra-segmental recombination, and accumulation of point mutations have possibly contributed to the emergence of this novel genotype of WRV, identified in China.
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Enfermedades de las Aves/virología , Orthoreovirus Aviar/clasificación , Infecciones por Reoviridae/veterinaria , Secuenciación Completa del Genoma/métodos , Animales , China , Patos , Tamaño del Genoma , Genoma Viral , Hígado/virología , Sistemas de Lectura Abierta , Orthoreovirus Aviar/genética , Orthoreovirus Aviar/aislamiento & purificación , Filogenia , Análisis de Secuencia de ARN , Bazo/virologíaRESUMEN
Muscovy duck reovirus (MDRV) is highly pathogenic to young Muscovy ducklings. Although MDRV infection results in ducklings' acute watery diarrhea, the effect of MDRV infection on the composition of host's intestinal microbiota remains poorly understood. This study was conducted to investigate the impacts of MDRV on the composition of Muscovy ducklings' intestinal bacterial community. Three-day-old Muscovy ducklings were inoculated with either the virulent MDRV strain MW9710 or sterile Hank's solution, respectively. The cecal microbiota was analyzed between control and mock MDRV-infected ducklings using Illumina MiSeq sequencing at 6 dpi and 17 dpi, respectively. The results indicated that MDRV infection damaged the intestinal mucosa. In addition, MDRV infection caused severe perturbations of gut microbiota by decreasing microbial richness, altering the abundance of certain genera of the gut microbiota at 6 dpi. Specifically, the relative abundance of short chain fatty acids-producing bacteria (including Shuttleworthia, Streptococcus, and Ruminococcus) was reduced in MDRV-infected ducklings than those of control group, whereas, with an enrichment of Enterobacteriaceae (including Plesiomonas, Escherichia_Shigella and Proteus). Furthermore, microbiota analysis showed that the gut microbiota dysbiosis caused by MDRV infection was basically recovered at 17 dpi. Collectively, this study demonstrated that the gut microbiota of Muscovy ducklings were altered due to MDRV infection, mainly featuring as a net loss of beneficial bacteria and a compensatory proliferation of pathogenic bacteria, which may lead to severe pathology to the intestinal mucosa, and ultimately acute diarrhea. These results will provide insights into the pathology of MDRV infection.
Asunto(s)
Microbioma Gastrointestinal , Mucosa Intestinal/patología , Mucosa Intestinal/virología , Orthoreovirus Aviar/patogenicidad , Enfermedades de las Aves de Corral/virología , Infecciones por Reoviridae/veterinaria , Factores de Edad , Animales , Patos/virología , Disbiosis , Mucosa Intestinal/microbiología , Infecciones por Reoviridae/complicacionesRESUMEN
Duckling short beak and dwarfism syndrome virus (SBDSV), a newly identified goose parvovirus, causes devastating disease in domestic waterfowl and considerable economic losses to Chinese waterfowl industry. The molecular pathogenesis of SBDSV infection, nature and dynamics of host immune responses against SBDSV infection remained elusive. In this study, we systematically explored the relative mRNA expression profiles of major innate immune-related genes in SBDSV infected duck embryo fibroblasts. We found that SBDSV infection effectively activated host innate immune responses and resulted in significant up-regulation of IFN-ß and several vital IFN-stimulated genes (ISGs). These up-regulation responses were mainly attributed to viral genomic DNA and dsRNA replication intermediates. Importantly, the expression of cGAS was significantly induced, whereas the expression of other DNA receptors including DDX41, STING, ZBP1, LSM14A and LRRFIP1 have no significant change. Furthermore, SBDSV infection also activates the up-regulation of TLR3 and inhibited the expression of TLR2 and TLR4; however, no effect was observed on the expression of TLR1, TLR5, TLR7, TLR15 and TLR21. Intriguingly, SBDSV infection significantly up-regulated the expression of RNA sensors such as MDA5 and LGP2, and resulted in a delayed but significant up-regulation of RIG-I gene. Taken together, these data indicate that host multiple sensors including DNA sensor (cGAS) and RNA sensors (TLR3, MDA5 and LGP2) are involved in recognizing a variety of different pathogen associated molecular patterns (PAMPs) including viral genomic ssDNA and dsRNA replication intermediates, which trigger an effective antiviral innate immune response.
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Enfermedades de las Aves/inmunología , Enfermedades de las Aves/virología , Interacciones Huésped-Patógeno/inmunología , Inmunidad Innata , Infecciones por Parvoviridae/veterinaria , Parvovirus/inmunología , Animales , Biomarcadores , Enfermedades de las Aves/metabolismo , Línea Celular , Células Cultivadas , ADN Viral/inmunología , Factores Reguladores del Interferón/metabolismo , ARN Viral/inmunología , Receptores de Reconocimiento de Patrones/metabolismo , Replicación ViralRESUMEN
Novel duck reovirus (NDRV) is pathogenic to young ducks, which is characterized by hemorrhagic spots and necrotic foci of the livers and necrotic foci of spleens. However, the effect of NDRV infection on the composition of the host's intestinal microbiota remains poorly understood. In this study, three-day-old Muscovy ducklings were inoculated with either the virulent NDRV strain NP03 or sterile Hank's solution. Through Illumina MiSeq sequencing, the whole cecal microbiota of healthy and NDRV infected ducklings was examined. The results showed that the gut microbiota was mainly dominated by Firmicutes, Proteobacteria and Bacteroidestes in both healthy and NDRV infected ducks. NDRV infection altered the relative abundance of bacteria. Specifically, families Ruminococcaceae and Lachnospiraceae were remarkably reduced, whereas Escherichia_Shigella belonging to family Enterobacteriaceae was significantly increased. Collectively, NDRV infection in Muscovy ducks resulted in a shift of the gut microbiota, including a net loss of probiotic bacteria with a compensatory expansion of pathogenic bacteria. These results provide new insights into the potential pathogenic mechanisms of NDRV.
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Disbiosis/microbiología , Microbioma Gastrointestinal , Interacciones Microbianas , Enfermedades de las Aves de Corral/microbiología , Infecciones por Reoviridae/veterinaria , Animales , Patos , Microbioma Gastrointestinal/genética , Hígado , Enfermedades de las Aves de Corral/virología , Probióticos , Reoviridae , Infecciones por Reoviridae/virología , BazoRESUMEN
Muscovy duck-origin goose parvovirus (MDGPV) is a causative agent of MDGPV-associated Derzsy's disease. To evalute the role of the cis-acting element E-box (CACATG) deletion on MDGPV eplication, an infectious plasmid clone p-PTΔE287, having one E-box deletion at nucleotide (nt) 287 of the left inverted terminal repeat sequence (L-ITR), was constructed by overlap extension PCR deleting the 287CACATG292 motif from the plasmid pMDGPVPT containing the full-length genome of the virulent MDGPV strain PT. The p-PTΔE287 plasmid was transfected into 9-day-old non-immune Muscovy duck embryos via the yolk sac, resulting in successful rescue of the deletion mutant virus r-PTΔE287. Compared with its parental virus PT, the virulence and the replication ability of r-PTΔE287 were reduced. In addition, we examined the ability of r-PTΔE287 to manipulate cell cycle progression. The results showed that r-PTΔE287 replication results in G0/G1 phase accumulation of infected duck embryo liver mesenchymal stem cells (BMSCs) and that this accumulation is caused by the prevention of cell cycle entry from G0/G1 phase into S phase. Taken together, introducing 287CACATG292 element deletion into MDGPV PT genomic DNA that induced rescued mutant virus (r-PTΔE287) cell cycle arrest function at the G0/G1 phase, which might inhibit MDGPV replication and virus progeny production. This study laid the foundation for further understanding of the relationship between E-box deletion in the L-ITR and MDGPV virulence.
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Puntos de Control del Ciclo Celular/genética , Enfermedades Transmisibles/genética , Parvovirinae/genética , Enfermedades de las Aves de Corral/genética , Animales , Enfermedades Transmisibles/virología , Patos/genética , Patos/virología , Embrión no Mamífero/virología , Gansos/genética , Gansos/virología , Genoma Viral/genética , Hígado/virología , Células Madre Mesenquimatosas/virología , Parvovirinae/patogenicidad , Plásmidos/genética , Enfermedades de las Aves de Corral/virología , Fase de Descanso del Ciclo Celular/genética , Fase S/genética , Eliminación de SecuenciaRESUMEN
The Muscovy duck reovirus (MDRV) is a highly pathogenic virus that causes substantial economic losses in the Muscovy duck industry. While MDRV poses a significant threat to Muscovy ducklings, no vaccine candidates are available to date to alleviate MDRV infection throughout the world. The present study presents efforts toward establishing an attenuated vaccine for MDRV. For this purpose, a live attenuated vaccine strain named CA was obtained via alternate propagation of the MDRV isolate MW9710 in both Muscovy duck embryo fibroblasts (MDEFs) and chicken embryo fibroblasts (CEFs) for 90 passages. The CA strain achieved an adaptive growth capacity in CEFs with a viral titer that ranged between 105.0-105.5 TCID50/100⯵L and lost its pathogenicity in 1-day-old Muscovy ducklings. Compared to the parent strain MW9710, the CA strain has 42 scattered amino acid substitutions, most of which are located in the λB, λC, µB, σB, and σC protein. The CA strain maintained its attenuation and showed no gene mutation or virulence reversion after back propagation into 1-day-old ducklings for five rounds. The minimum protective dose was calculated to be 300 TCID50 of the CA strain. Furthermore, a single dose of CA vaccine protected immunized ducklings against lethal challenge by the virulent MDRV strain MW9710 and significantly decreased viral loads. In summary, the CA strain exhibited striking genetic stability, excellent safety, and effective immunogenicity. This CA strain of MDRV is a promising vaccine candidate for the prevention and control of MDRV infection.
Asunto(s)
Orthoreovirus Aviar/inmunología , Enfermedades de las Aves de Corral/prevención & control , Infecciones por Reoviridae/veterinaria , Vacunas Virales/inmunología , Animales , Pollos/inmunología , Patos/inmunología , Fibroblastos/virología , Inmunogenicidad Vacunal , Orthoreovirus Aviar/genética , Enfermedades de las Aves de Corral/inmunología , Infecciones por Reoviridae/prevención & control , Vacunas Atenuadas/administración & dosificación , Vacunas Atenuadas/inmunología , Carga ViralRESUMEN
To obtain a deletion mutant of Muscovy duck-origin goose parvovirus (MDGPV) and to analyze its biological characteristics, the pMDGPVPT plasmid, which contains a full-length DNA infectious clone of the MDGPV PT strain, was used in this study as the template. The E-box at nt 315 of the left inverted terminal repeat sequence (L-ITR) was deleted by overlap extension PCR to obtain the infectious recombinant plasmid p-PTΔE315. The p-PTΔE315 plasmid was transfected into 9-day-old non-immune Muscovy duck embryos via the yolk sac and the rescued deletion mutant virus r-PTΔE315 was generated. Experiments to demonstrate the novel deletion mutant virus' biological characteristics showed that r-PTΔE315 can cause typical lesions after infection of Muscovy duck embryos. Compared with its parent strain PT, the virulence of r-PTΔE315 and its proliferation ability in Muscovy duck embryos were attenuated, but its ability to replicate in MDEF cells was enhanced. This study laid the foundation for further understanding of the relationship between E-box deletion in the L-ITR and MDGPV virulence.
Asunto(s)
Patos/virología , Elementos E-Box/genética , Gansos/virología , Técnicas Genéticas , Parvovirus/genética , Eliminación de Secuencia , Animales , Secuencia de Bases , Células ClonalesRESUMEN
Short beak and dwarfism syndrome virus (SBDSV) is a newly emerging distinct duck-origin goose parvovirus that belongs to the genus Dependovirus. Our previous studies have found that SBDSV was highly pathogenic to Cherry Valley ducklings and mule ducklings. However, little is known about its pathogenicity to other waterfowls. In the present study, the pathogenicity of SBDSV was evaluated in domesticated waterfowl including Muscovy ducklings, Sheldrake ducklings and domestic goslings. All experimentally infected birds exhibited remarkable growth retardation, anorexia and diarrhea similar to naturally infected birds. Interestingly, atrophic beaks and protruded tongues were not observed in all infection groups. At necropsies, no diagnostic pathological lesions were observed. Viral antigens existed in most organ tissues such as heart, liver, spleen, kidney, pancreas and intestine. All ducks in Muscovy duckling and Sheldrake duckling infected groups and 70% goslings in infected groups were seropositive for goose parvovirus (GPV) antibodies at 21dpi with the average titers as 28.4, 26.9, 24.0, respectively. Muscovy ducklings were more prominent in viral load and weight loss with a higher GPV antibodies titer than Sheldrake ducklings and goslings. Taken together, SBDSV exhibits a wide range of pathogenicity to main domesticated waterfowl with variable symptoms and cause considerable economic losses in China.
Asunto(s)
Enfermedades de las Aves/virología , Patos/virología , Parvovirinae/patogenicidad , Animales , Anseriformes , Enfermedades de las Aves/epidemiología , Parvovirinae/aislamiento & purificación , Carga Viral , VirulenciaAsunto(s)
Enanismo/veterinaria , Infecciones por Parvoviridae/diagnóstico , Polimorfismo de Longitud del Fragmento de Restricción , Enfermedades de las Aves de Corral/virología , Animales , Secuencia de Bases , Pico/anatomía & histología , ADN Viral/genética , Patos , Enanismo/diagnóstico , Enanismo/virología , Infecciones por Parvoviridae/veterinaria , Infecciones por Parvoviridae/virología , Parvovirinae/genética , Parvovirinae/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Enfermedades de las Aves de Corral/diagnóstico , Sensibilidad y EspecificidadRESUMEN
Many mule duck and Cherry Valley duck flocks in different duck-producing regions of China have shown signs of an apparently new disease designated "short beak and dwarfism syndrome" (SBDS) since 2015. The disease is characterized by dyspraxia, weight loss, a protruding tongue, and high morbidity and low mortality rates. In order to characterize the etiological agent, a virus designated SBDSV M15 was isolated from allantoic fluid of dead embryos following serial passage in duck embryos. This virus causes a cytopathic effect in duck embryo fibroblast (DEF) cells. Using monoclonal antibody diagnostic assays, the SBDSV M15 isolate was positive for the antigen of goose parvovirus but not Muscovy duck parvovirus. A 348-bp (2604-2951) VP1gene fragment was amplified, and its sequence indicated that the virus was most closely related to a Hungarian GPV strain that was also isolated from mule ducks with SBDS disease. A similar disease was reproduced by inoculating birds with SBDSV M15. Together, these data indicate that SBDSV M15 is a GPV-related parvovirus causing SBDS disease and that it is divergent from classical GPV isolates.
Asunto(s)
Pico/patología , Patos , Enanismo/veterinaria , Transmisión Vertical de Enfermedad Infecciosa , Parvovirus/clasificación , Enfermedades de las Aves de Corral/virología , Animales , China/epidemiología , Enanismo/virología , Pruebas de Fijación de Látex , Microscopía Acústica , Parvovirus/genética , Parvovirus/patogenicidad , Parvovirus/ultraestructura , Filogenia , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/patología , Pruebas Serológicas/veterinariaAsunto(s)
Pico/anomalías , Enanismo , Infecciones por Parvoviridae , Parvovirinae , Animales , China , Patos/virología , Enanismo/veterinaria , Enanismo/virología , Infecciones por Parvoviridae/genética , Infecciones por Parvoviridae/mortalidad , Infecciones por Parvoviridae/veterinaria , Infecciones por Parvoviridae/virología , Parvovirinae/clasificación , Parvovirinae/genética , Parvovirinae/patogenicidad , FilogeniaRESUMEN
To determine the origin and evolution of goose parvovirus (GPV) and Muscovy duck parvovirus (MDPV) in the Mainland of China, phylogenetic and recombination analyses in the present study were performed on 32 complete VP1 gene sequences from China and other countries. Based on the phylogenetic analysis of the VP1 gene, GPV strains studied here from Mainland China (PRC) could be divided into three genotypes, namely PRC-I, PRC-II and PRC-III. Genotype PRC-I is indigenous to Mainland China. Only one GPV strain from Northeast China was of Genotype PRC-II and was thought to be imported from Europe. Genotype PRC-III, which was the most isolated genotype during 1999-2012, is related to GPVs in Taiwan and has been the predominant pathogen responsible for recent Derzy's disease outbreaks in Mainland China. Current vaccine strains used in Mainland China belong to Genotype PRC-I that is evolutionary distant from Genotypes PRC-II and PRC-III. In comparison, MDPV strains herein from Mainland China are clustered in a single group which is closely related to Taiwanese MDPV strains, and the full-length sequences of the VP1 gene of China MDPVs are phylogenetic closely related to the VP1 sequence of a Hungarian MDPV strain. Moreover, We also found that homologous recombination within VP1 gene plays a role in generating genetic diversity in GPV evolution. The GPV GDFSh from Guangdong Province appears to be the evolutionary product of a recombination event between parental GPV strains GD and B, while the major parent B proved to be a reference strain for virulent European GPVs. Our findings provide valuable information on waterfowl parvoviral evolution in Mainland China.
Asunto(s)
Proteínas de la Cápside/genética , Variación Genética , Parvovirus/clasificación , Parvovirus/genética , China , Genotipo , Humanos , Filogenia , Filogeografía , Recombinación Genética , Análisis de Secuencia de ADNRESUMEN
To investigate the possible role of recombination in the evolution of Muscovy duck parvovirus (MDPV) and goose parvovirus (GPV) in Taiwan, we analyzed a potentially significant recombination event that occurred only in GPV by comparing thirteen complete sequences of the capsid gene VP2 of GPV and MDPV. The recombination event occurred between GPV strain 06-0239 as the minor parent and strains 99-0808 as the major parent, which resulted in the GPV recombinant V325/TW03. GPV V325/TW03 is likely to represent a new genotype among the Taiwanese GPV strains. This represents the first evidence that intergenotype recombination within the VP2 gene cluster contributes to the genetic diversity of the VP2 genes of Taiwanese GPV field strains.