Search Results (9)

The novel goose parvovirus (NGPV) and the novel duck reovirus (NDRV) are pathogens that can substantially affect the growth and development of ducklings, causing considerable economic losses to duck farms. Therefore, a timely, rapid, accurate, and high-throughput diagnosis and identification of viral infections are critical for preventing the spread of epidemics. In this study, a TaqMan probe-based duplex one-step RT-qPCR was established for the simultaneous detection and qualitative and quantitative identification of the two viruses. It demonstrated greater sensitivity than conventional PCR, detecting as low as 2.42 copies/μL of NGPV genome and 70.1 copies/μL of NDRV genome. Additionally, it exhibited remarkable specificity, responding exclusively to the nucleic acids of target pathogens. It also demonstrated excellent reproducibility and availability, particularly in clinical settings, with a coinfection detection rate of 13.3%, contributing to the development of NGPV- and NDRV-testing technologies. Full article

The novel goose parvovirus (N-GPV), responsible for beak atrophy and dwarfism syndrome (BADS), has caused significant economic losses in China’s duck-raising industry. In this study, a highly virulent N-GPV strain NMG21 was serially passaged in duck embryo fibroblast cells (DEFs). The virus titers and virulence of selected passages were evaluated in 1-day-old ducklings. An increased virus titer was observed at the 5th passage (P5). Compared with the parent strain NMG21, the P35 (NMG21-35 strain) has a clear decrease in pathogenicity for ducklings, with less tissue damage. The NMG21-35 also exhibited relatively lower tissue replication rates and higher antibody levels. Collectively, the virulence of N-GPV strain NMG21 was reduced via serial passage in DEFs for 35 passages. Our research successfully prepared a N-GPV attenuated variant which might serve as a potential live vaccine candidate against N-GPV infection. Developing a live attenuated vaccine candidate against N-GPV infection in China is crucial for mitigating the economic impact of N-GPV on the duck industry. Full article

Goose parvovirus (GPV), duck enteritis virus (DEV), Muscovy duck parvovirus (MDPV), duck hepatitis A virus type 1 (DHAV-1), duck hepatitis A virus type 3 (DHAV-3), duck Tembusu virus (DTMUV), and novel duck reovirus (NDRV) are significant pathogens that spread extensively among waterfowl populations, causing economic losses for the waterfowl industry. In order to detect seven pathogens simultaneously, a visual gene chip for the detection of multiple waterfowl disease pathogens was developed in this study. The gene chip was capable of specifically amplifying GPV, DEV, MDPV, DHAV-1, –DHAV-3, DTMUV, and NDRV. The sensitivity results showed that the lowest detection limit of the gene chip was 1 copy/μL for single and mixed samples. The reproducibility and stability tests demonstrated that the gene chip developed in this experiment exhibited not only excellent reproducibility but also remarkable stability, remaining functional for a minimum of 180 days. Compared to qPCR methods, the results showed that the sensitivity of the gene chip was slightly better than that of the qPCR method in detecting both single and mixed pathogens of the seven viruses. In this study, a total of 210 clinical samples were detected by the gene chip and qPCR, respectively, and the results of the two methods had a concordance rate of 98.1~100%, with a kappa value of 0.952, indicating that the consistency of the two detection methods was good. Full article

The present study aims to better understand the nature of currently circulating GPV strains and their pathological impact on the immune system during natural outbreaks among different duck breeds in Egypt. For this purpose, 99 ducks (25 flocks) of different breeds, aged 14–75 days, were clinically examined, and 75 tissue pools from the thymus, bursa of Fabricius, and spleen were submitted for virus detection and identification. Clinical and postmortem findings were suggestive of GPV infection. Concerning the immune system organs, atrophy in the thymus (60.6%), bursa (45.5%), and spleen (38.3%) was the most common gross lesion. Microscopically, the pathological impact of the virus was exhibited by a necrotic thymic cortex with Hassall’s corpuscle disintegration, the disappearance of normal bursal histological morphology accompanied by atrophied follicles and lymphocytic depletion, and apoptosis of B-lymphocytes in lymphoid follicles of the spleen. Furthermore, immunohistochemical examination revealed positive signals of the parvovirus detected in thymic lymphocytes in the cortex, bursa-dependent lymphoid follicle of the medulla, and diffuse positive expression of viral antigens in the spleen. GPV was detected in ducks using polymerase chain reaction, with the highest percentage of positive detection in the bursa of Fabricius (76%). Next-generation sequencing and phylogenetic analysis revealed that the detected virus was a variant of GPV, globally named novel GPV (NGPV), and closely related to Chinese NGPV isolates. To our knowledge, the current study is pioneering to address the immunopathological impact of NGPV among naturally infected ducks confirmed with full genome sequencing and immunohistochemical identification worldwide. Full article

Novel goose parvovirus (NGPV), a genetic variant of goose parvovirus, has been spreading throughout China since 2015 and mainly infects ducklings with the symptoms of growth retardation, beak atrophy, and protruding tongue, leading to huge economic losses every year. A safe and effective vaccine is urgently needed to control NGPV infection. In this study, virus-like particles (VLPs) of NPGV were assembled and evaluated for their immunogenicity. The VP2 protein of NGPV was expressed in Spodoptera frugiperda insect cells using baculovirus as vector. The VP2 protein was efficiently expressed in the nucleus of insect cells, and the particles with a circular or hexagonal shape and a diameter of approximately 30 nm, similar to the NGPV virion, were observed using transmission electron microscopy (TEM). The purified particles were confirmed to be composed of VP2 using western blot and TEM, indicating that the VLPs of NGPV were successfully assembled. Furthermore, the immunogenicity of the VLPs of NGPV was evaluated in Cherry Valley ducks. The level of NGPV serum antibodies increased significantly at 1–4 weeks post-immunization. No clinical symptoms or deaths of ducks occurred in all groups after being challenged with NGPV at 4 weeks post-immunization. There was no viral shedding in the immunized group. However, viral shedding was detected at 3–7 days post-challenge in the non-immunized group. Moreover, VLPs can protect ducks from histopathological lesions caused by NGPV and significantly reduce viral load in tissue at 5 days post-challenge. Based on these findings, NGPV VLPs are promising candidates for vaccines against NGPV. Full article

In total, 130 tissue-pooled samples collected from ducks in some provinces/cities in north Vietnam were examined for waterfowl parvovirus genome identification. Twenty-six (20%) samples were positive for the parvovirus infection, based on polymerase chain reaction analysis. Of the 38 farms tested, 14 (36.84%) were positive for the waterfowl parvovirus genome. The rate of the parvovirus genome detection in ducks aged 2–4 weeks (37.04%) was significantly (p < 0.05) higher than that at ages <2 weeks (9.09%) and >4 weeks (16.30%). The positive rate on medium-scale farms (9.36%) was significantly (p < 0.05) lower than for small-scale (31.03%) and large-scale (29.73%) farms. The lengths of the four Vietnamese waterfowl parvovirus genomes identified were 4750 nucleotides. Among the four Vietnamese parvovirus genomes, nucleotide identities were from 99.29% to 99.87%. Phylogenetic analysis of the near-complete genomes indicated that the waterfowl circulating in northern Vietnam belonged to the novel goose parvovirus (NGPV) group. The Vietnamese NGPV group was closely related to the Chinese group. Recombination analysis suggested that the Vietnam/VNUA-26/2021 strain was generated by a recombination event. One positive selection site of the capsid protein was detected. Full article

Gosling plague (GP) is an acute and hemorrhagic infectious disease caused by goose parvovirus (GPV). The goose industry suffers significant economic losses as a result of GP, which is found to be widespread worldwide, with high rates of morbidity and mortality. Our group developed a novel technique for detecting GPV nanoparticle-assisted polymerase chain reaction (nanoPCR) and the characterization of its specificity and sensitivity. It was developed by using the traditional polymerase chain reaction (PCR) and nanoparticles. The findings of this study revealed that GPV nanoPCR products were 389 bp in length, and the lower limit of the nanoPCR assay was 4.68 × 10² copies/μL, whereas that of the conventional PCR assay was 4.68 × 10⁴ copies/μL. A total of 230 geese suspected of GPV were detected using nanoPCR, with a positive rate of 83.0% and a specificity of 73%, respectively. Overall, we present a hitherto undocumented method for identifying GPV by using nanoPCR to aid in the evaluation of subclinical illness. Full article

Short beak and dwarfism syndrome (SBDS), which was previously identified only in mule ducks, is now an emerging disease of Pekin ducks in China and Egypt. The disease is caused by the infection of ducks with a genetic variant of goose parvovirus—novel goose parvovirus (nGPV). In 2019, SBDS was observed for the first time in Poland in eight farms of Pekin ducks. Birds in the affected flock were found to show growth retardation and beak atrophy with tongue protrusions. Morbidity ranged between 15% and 40% (in one flock), while the mortality rate was 4–6%. Co-infection with duck circovirus, a known immunosuppressive agent, was observed in 85.7% of ducks. The complete coding regions of four isolates were sequenced and submitted to GenBank. The phylogenetic analysis revealed a close relationship of Polish viral sequences with the Chinese nGPV. Genomic sequence alignments showed 98.57–99.28% identity with the nGPV sequences obtained in China, and 96.42% identity with the classical GPV (cGPV; Derzsy’s disease). The rate of amino acid mutations in comparison to cGPV and Chinese nGPV was higher in the Rep protein than in the Vp1 protein. To our knowledge, this is the first report of nGPV infection in Pekin ducks in Poland and Europe. It should be emphasized that monitoring and sequencing of waterfowl parvoviruses is important for tracking the viral genetic changes that enable adaptation to new species of waterbirds. Full article

Derzsy’s disease causes disastrous losses in domestic waterfowl farms. A genetically variant strain of Muscovy duck parvovirus (MDPV) and goose parvovirus (GPV) was named novel goose parvovirus (NGPV), which causes characteristic syndrome in young ducklings. The syndrome was clinically characterized by deformity in beaks and retarded growth, called short beaks and dwarfism syndrome (SBDS). Ten mule and pekin duck farms were investigated for parvovirus in three Egyptian provinces. Despite low recorded mortality rate (20%), morbidity rate was high (70%), but the economic losses were remarkable as a result of retarded growth and low performance. Isolation of NGPV was successful on primary cell culture of embryonated duck liver cells with a clear cytopathic effect. Partial gene sequence of the VP1 gene showed high amino acids identity among isolated strains and close identity with Chinese strains of NGPV, and low identity with classic GPV and MDPV strains. To the best of our knowledge, this can be considered the first record of NGPV infections in Egypt. Full article