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In this study, we develop a reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay for rapid and easy detection of goose astroviruses (GAstVs) in clinical samples. The specific LAMP primer sets were designed targeting the ORF2 gene of GAstV. The conditions of LAMP amplification were optimized in terms of reaction time and temperature. The optimal conditions are 60 min in a 60 °C water bath. No cross-reactivity was noted with fowl adenovirus serotype 4 (FAdV-4), duck tembusu virus (DTMUV), goose parvovirus (GPV), avian infectious bronchitis virus (IBV), or chicken anemia virus (CAV). The proposed RT-LAMP method was compared with conventional RT polymerase chain reaction (RT-PCR) and with nested RT-PCR. The results showed that the sensitivity of the proposed method was comparable to that of nested RT-PCR and tenfold higher than that of the conventional RT-PCR. Clinical samples (N = 129) of the liver and kidney from sick geese collected from six commercial goose farms were tested. The positive rate was 39.5% (51/129), 38.8% (50/129), and 34.9% (45/129) using RT-LAMP, nested RT-PCR and conventional RT-PCR, respectively. The developed RT-LAMP diagnostic method is not only simple, rapid, and highly specific, but also portable for use on the field. It may be used in epidemiological investigation to detect GAstVs.

Orf, also called contagious ecthyma or contagious pustular dermatitis, is a significant zoonotic disease that primarily affects goat and sheep globally. Currently, the infection by orf virus (ORFV) has been observed in different host species worldwide, including China. Here, a suspected outbreak of orf infection in a goat farm in Anhui Province in 2018 was investigated. Through PCR, electron microscopy, and cell culture techniques, we confirmed that the outbreak was caused by ORFV. Consequently, the orf virus strain was named the AH/LA/2018 strain. The amplified and sequenced ORFV011 (B2L) and ORFV059 (F1L) genes were used to construct phylogenetic trees to elucidate the genetic characteristics of the ORFV and the molecular epidemiology of orf. The present study is the first systematic evolution analysis of the ORFV strain isolated in Anhui Province. The results of this study will be helpful to better understand the characteristics of ORFV, to help prevent and control the transmission of ORFV at an early stage in China.

Duck short beak and dwarf syndrome (SBDS) is a viral infectious disease caused by novel duck parvovirus (NDPV). It has brought serious economic losses to the Chinese duck industry in recent years. Currently, there exists no effective vaccine against this disease. In this study, we developed an inactivated virus vaccine based on NDPV-DS15 for SBDS. Immune efficacy was evaluated in 112 ducks, which were randomly divided into vaccination, challenge control, vaccination-challenge, and blank control groups (n = 28 each). Clinical characteristics, antibodies, viral excretion, viremia, and pathological changes were monitored and analyzed. No morbidity or death was observed in the immunized ducks, which showed normal weight and good mental state. High levels of serum antibodies (OD450 nm: ~0.63) were detected in ducks immunized with inactivated vaccine at 7 days post-vaccination (dpv), and the amount of virus neutralizing antibodies increased from 1:23 to 1:28.5 from 7 dpv to 42 dpv. The anal swab, serum, and tissue viral load tests showed that vaccination could significantly inhibit the replication of NDPV in immunized ducks. Moreover, NDPV could not be isolated from the spleens of immunized or vaccination-challenged ducks. Our results show that the developed inactivated NDPV vaccine, administered in an oil emulsion adjuvant, possesses good immunogenicity and represents a potentially powerful tool for SBDS prevention and control.

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Background: Vesicular stomatitis (VS) is an acute, highly contagious and economically important zoonotic disease caused by the vesicular stomatitis virus (VSV). There is a need for effective and safe stable recombinant vaccine for the control of the disease. The human type 5 replication-defective adenovirus expression vector is a good way to construct recombinant vaccines.Results: Three recombinant adenoviruses (rAd) were successfully constructed that expressed the VSV Indiana serotype glycoprotein (VSV-IN-G), VSV New Jersey serotype glycoprotein (VSV-NJ-G), and the G fusion protein (both serotypes of G [VSV-IN-G-NJ-G]) with potentiality to induce protective immunity. G proteins were successfully expressed with good immunogenicity. The rAds could induce the production of VSV antibodies in mice, and VSV neutralizing antibodies in goats, respectively. The neutralizing antibody titers could reach 1:32 in mice and 1:64 in goats. The rAds induced strong lymphocyte proliferation in mice and goats, which was significantly higher compared to the negative control groups. Conclusions: The three rAds constructed in the study expressed VSV-G proteins and induced both humoral and cellular immune responses in mice and goats. These results lay the foundation for further studies on the use of rAds in vaccines expressing VSV-G.