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Pigeon paramyxovirus type 1 (PPMV-1) is a globally distributed, virulent member of the avian paramyxovirus type-1. The PPMV-1-associated disease poses a great threat to the pigeon industry. The innate immune response is crucial for antiviral infections and revealing the pathogenic mechanisms of PPMV-1. In this study, we evaluated the pathogenicity of a PPMV-1 strain LHLJ/110822 in one-month-old domestic pigeons, as well as the host immune responses in PPMV-1-infected pigeons. We observed typically clinical sign in infected pigeons by 3 dpi. The morbidity rate and the mortality in pigeons inoculated with the PPMV-1 strain were up to 100% and 30%, respectively. The virus could replicate in all of the examined tissues, namely trachea, lung, liver, spleen, and bursa of Fabricius. In addition, the infected pigeons had developed anti-PPMV-1 antibodies as early as 8 dpi; and the antibody level increased over the time in this study. The expression level of toll-like receptor (TLR) 2, TLR3 TLR15, IFN-γ, and IL-6 were significantly upregulated by the PPMV-1 infection in some tissues of pigeons. By contrast, PPMV-1 infection results in downregulation of IL-18 expression in most of investigated tissues except for bursa of Fabricius in this study. The current results confirmed that this virus could replicate in pigeons and induce host immune responses, then leading to produce serum antibody titers. Meanwhile, the PPMV-1 infection induces strong innate immune responses and intense inflammatory responses at early stage in pigeon which may associate with the viral pathogenesis., (Copyright © 2020. Published by Elsevier Inc.)

The industrialization of farming has had an enormous impact. To most, this impact is viewed solely in the context of productivity, but the denser living conditions and shorter rearing periods of industrial livestock farms provide pathogens with an ideal opportunity to spread and evolve. For example, the industrialization of poultry farms drove the Marek's disease virus (MDV) to evolve from a mild paralytic syndrome to a highly contagious, globally prevalent, deadly disease. Fortunately, the economic catastrophe that would occur from MDV evolution is prevented through the widespread use of live imperfect vaccines that limit disease symptoms, but fail to prevent transmission. Unfortunately, the continued rollout of such imperfect vaccines is steering MDV evolution towards even greater virulence, and the ability to evade vaccine protection. Thus, there is a need to investigate alternative economically viable control measures for their ability to inhibit MDV spread and evolution. In what follows we examine the economic viability of standard husbandry practices for their ability to inhibit the spread of both virulent MDV and very virulent MDV throughout an industrialized egg farm. To do this, we parameterize a MDV transmission model and calculate the loss in egg production due to MDV. We find that MDV strain and the cohort duration have the greatest influence on both disease burden and egg production. Additionally, our findings show that for long cohort durations, conventional cages result in the least per capita loss in egg production due to MDV infection, while Aviary systems perform best over shorter cohort durations. Finally, we find that the least per capita loss in egg production for flocks infected with the more virulent MDV strains occurs when cohort durations are sufficiently short. These results highlight the important decisions that managers will face when implementing new hen husbandry practices., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

High-pathogenicity avian influenza (HPAI) virus, low-pathogenicity avian influenza (LPAI) virus, virulent Newcastle disease virus (vNDV) and low-virulent Newcastle disease virus (lNDV) can be present on the eggshell surface, and HPAI viruses and vNDV can be present in the internal contents of chicken eggs laid by infected hens. With the increase in global trade, egg products could present potential biosecurity problems and affect international trade in liquid and dried egg products. Therefore, the generation of survival curves to determine decimal reduction times (D(T)-values) and change in heat resistance of the viruses (z(D)-value) within fat-free egg product could provide valuable information for development of risk reduction strategies. Thermal inactivation studies using A/chicken/Pennsylvania/1370/83 (H5N2) HPAI virus resulted in D(55)-, D(56)-, D(56.7)-, D(57)-, D(58)-, and D(59)-values of 18.6, 8.5, 3.6, 2.5, 0.4, and 0.4 min, respectively. The z(D)-value was 4.4 °C. LPAI virus A/chicken/New York/13142/94 (H7N2) had D(55)-, D(56.7)-, D(57)-, D(58)-, D(59)-, and D(60)-values of 2.9, 1.4, 0.8, 0.7, 0.7, and 0.5 min, respectively, and a z-value of 0.4 °C. vNDV avian paramyxoviruses of serotype 1 (AMPV-1)/chicken/California/212676/2002 had D(55)-, D(56)-, D(56.7)-, D(57)-, D(58)-, and D(59)-values of 12.4, 9.3, 6.2, 5, 3.7, and 1.7 min, respectively. The z(D)-value was 4.7 °C. lNDV AMPV-1/chicken/United States/B1/1948 had D(55)-, D(57)-, D(58)-, D(59)-, D(61)-, and D(63)-values of 5.3, 2.2, 1.1, 0.55, 0.19, and 0.17 min, respectively, and a z(D)-value of 1.0 °C. Use of these data in developing egg pasteurization standards for AI and NDV-infected countries should allow safer trade in liquid egg products., (Copyright ©, International Association for Food Protection)

Catechin derivatives with different alkyl chain length and aromatic ring substitutions at the 3-hydroxyl group were synthesized from epigallocatechin (EGC) and (+)-catechin (C) and their anti-influenza viral activity were evaluated in vitro and in ovo. Pronounced antiviral activity was observed for derivatives carrying moderate chain length (7-9 carbons) as compared to those with aromatic rings, whereas the 5'-hydroxyl group of the trihydroxy benzyl moiety did not significantly contribute to antiviral activity. The derivatives exerted inhibitory effects for all six influenza subtypes tested including three major types of currently circulating human influenza viruses (A/H1N1, A/H3N2 and B type), H2N2 and H9N2 avian influenza virus. The compounds strongly inhibited adsorption of the viruses on red blood cell (RBC). They also restricted the growth of avian influenza virus in ovo with minimum inhibition concentration (MIC) of 5-10 microM far exceeding the neuraminidase (NA) inhibitor oseltamivir or M2 proton channel inhibitor amantadine. The antiviral activity appears to be mediated by interaction with hemagglutinin (HA)/viral membrane rendering HA less fusogenic at the initial stage of infection. The broad spectrum activity against various subtypes of influenza viruses may complement the limitations of current antivirals and contribute for managing potentially emerging influenza pandemic. The structure-activity data of catechin derivatives may usefully guideline future research endeavors for applying green tea catechins as alternative anti-viral agents.

Detecting internal Salmonella Enteritidis (SE) contamination in eggs is essential for protecting public health. Pooling together > or = 10 eggs for sampling allows many eggs to be screened for contamination, but such pools must be incubated (usually at 25 to 37 degrees C) to permit small numbers of SE to multiply before further testing. The present study determined whether incubating egg contents pools at an elevated temperature (42 degrees C) could increase the rate of multiplication of a phage type 14b strain of SE sufficiently to support the detection of contamination by a rapid lateral flow immunodiffusion method within a single day. Pools of 10 eggs were contaminated with approximately 10 CFU of SE, supplemented with concentrated broth enrichment medium, and incubated at either 37 or 42 degrees C. Incubation of contaminated egg pools at 42 degrees C resulted in significantly higher SE levels after 6, 8, 10, and 12 h. However, incubation at 42 degrees C could only generate a mean log SE concentration of 4.21 CFU/ml within a single working day (8 h), inadequate to support efficient detection by most rapid assays. Detection of SE contamination in egg pools by a rapid lateral flow immunodiffusion test was not achieved at a high frequency until 12 h of incubation at 42 degrees C.

Infectious bursal disease (IBD) of chickens and hemorrhagic enteritis (HE) of turkeys are caused by infectious bursal disease virus (IBDV) and hemorrhagic enteritis virus (HEV), respectively. Both diseases have common features, including an acute stage followed by immunosuppression, resulting in lowered resistance to a variety of infectious agents and poor response to commonly used vaccines. The IBDV and HEV infections are widespread in commercial chicken and turkey flocks, respectively. The acute stage of the disease, the immunosuppression that follows, and the widespread distribution of both diseases, are major factors contributing to the economic significance of both diseases. The mechanism of immunosuppression for both infections has similarities, both affect lymphocytes and macrophages, and both are lymphocidal. In this report, an overview of both diseases with emphasis on some of the recent findings will be presented. There has been greater research activity on IBD than on HE, reflecting the relative economic importance of the species affected and the recent changes in the antigenic make up and pathogenicity of the IBDV.