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Poultry Science May 2024Avian influenza, particularly the H9N2 subtype, presents significant challenges to poultry health, underscoring the need for effective antiviral interventions. This...
Avian influenza, particularly the H9N2 subtype, presents significant challenges to poultry health, underscoring the need for effective antiviral interventions. This study explores the antiviral capabilities of Belamcanda extract, a traditional Chinese medicinal herb, against H9N2 Avian influenza virus (AIV) in specific pathogen-free (SPF) chicks. Through a comprehensive approach, we evaluated the impact of the extract on cytokine modulation and crucial immunological signaling pathways, essential for understanding the host-virus interaction. Our findings demonstrate that Belamcanda extract significantly modulates the expression of key inflammatory cytokines, including tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1), interleukin-2 (IL-2), and interleukin-6 (IL-6), which are pivotal to the host's response to H9N2 AIV infection. Western blot analysis further revealed that the extract markedly reduces the expression of critical immune signaling molecules such as toll-like receptor 3 (TLR3), TIR-domain-containing adapter-inducing interferon-β (TRIF), and nuclear factor kappa B (NF-κB). These insights into the mechanisms by which Belamcanda extract influences host immune responses and hinders viral replication highlight its potential as an innovative antiviral agent for poultry health management. The study advances our comprehension of natural compounds' antiviral mechanisms and lays the groundwork for developing strategies to manage viral infections in poultry. The demonstrated ability of Belamcanda extract to modulate immune responses and inhibit viral replication establishes it as a promising candidate for future antiviral therapy development, especially in light of the need for effective treatments against evolving influenza virus strains and the critical demand for enhanced poultry health management strategies.
PubMed: 38851182
DOI: 10.1016/j.psj.2024.103885 -
Emerging Infectious Diseases Jul 2024During March and April 2024, we studied dairy cattle specimens from a single farm in Texas, USA, using multiple molecular, cell culture, and next-generation sequencing...
During March and April 2024, we studied dairy cattle specimens from a single farm in Texas, USA, using multiple molecular, cell culture, and next-generation sequencing pathogen detection techniques. Here, we report evidence that highly pathogenic avian influenza A(H5N1) virus strains of clade 2.3.4.4b were the sole cause of this epizootic.
Topics: Animals; Texas; Cattle; Influenza A Virus, H5N1 Subtype; Cattle Diseases; Phylogeny; Influenza in Birds; Dairying; Female
PubMed: 38848249
DOI: 10.3201/eid3007.240717 -
Emerging Microbes & Infections Dec 2024Since 2007, h9.4.2.5 has emerged as the most predominant branch of H9N2 avian influenza viruses (AIVs) that affects the majority of the global poultry population. The...
Since 2007, h9.4.2.5 has emerged as the most predominant branch of H9N2 avian influenza viruses (AIVs) that affects the majority of the global poultry population. The spread of this viral branch in vaccinated chicken flocks has not been considerably curbed despite numerous efforts. The evolutionary fitness of h9.4.2.5-branched AIVs must consequently be taken into consideration. The glycosylation modifications of hemagglutinin (HA) play a pivotal role in regulating the balance between receptor affinity and immune evasion for influenza viruses. Sequence alignment showed that five major HA glycosylation patterns have evolved over time in h9.4.2.5-branched AIVs. Here, we compared the adaptive phenotypes of five virus mutants with different HA glycosylation patterns. According to the results, the mutant with 6 N-linked glycans displayed the best acid and thermal stability and a better capacity for multiplication, although having a relatively lower receptor affinity than 7 glycans. The antigenic profile between the five mutants revealed a distinct antigenic distance, indicating that variations in glycosylation level have an impact on antigenic drift. These findings suggest that changes in the number of glycans on HA can not only modulate the receptor affinity and antigenicity of H9N2 AIVs, but also affect their stability and multiplication. These adaptive phenotypes may underlie the biological basis for the dominant strain switchover of h9.4.2.5-branched AIVs. Overall, our study provides a systematic insight into how changes in HA glycosylation patterns regulate the evolutionary fitness and epidemiological dominance drift of h9.4.2.5-branched H9N2 AIVs, which will be of great benefit for the glycosylation-dependent vaccine design.
Topics: Glycosylation; Influenza A Virus, H9N2 Subtype; Animals; Hemagglutinin Glycoproteins, Influenza Virus; Influenza in Birds; Chickens; Mutation; Polysaccharides; Virus Replication; Madin Darby Canine Kidney Cells; Poultry Diseases
PubMed: 38847071
DOI: 10.1080/22221751.2024.2364736 -
Frontiers in Veterinary Science 2024Avian coccidiosis, a parasitic disease prevalent in poultry, is caused by species and leads to significant economic losses. The use of attenuated live oocyst vaccines...
Avian coccidiosis, a parasitic disease prevalent in poultry, is caused by species and leads to significant economic losses. The use of attenuated live oocyst vaccines has been adopted as an alternative to the use of anticoccidial drugs. However, the accurate detection and differentiation of vaccine strains from virulent ones remain challenging. Therefore, this study presents a novel TaqMan polymerase chain reaction (PCR) detection method that offers enhanced sensitivity, specificity, and reproducibility compared with traditional PCR techniques. Through whole-genome resequencing and bioinformatics analysis, we identified a molecular marker gene, Em_marker6, with a unique 21-base pair deletion specific to the attenuated vaccine strain. Optimized primers and probes targeting this marker enabled rapid quantification cycle value achievement and high fluorescence intensity. The standard curve's slope of -3.540 and correlation coefficient of 0.9971 confirmed precise quantification capabilities. The TaqMan PCR method detected as few as 30 plasmid DNA copies and 50 oocysts per reaction, outperforming traditional PCR techniques by an order of magnitude. No cross-reactivity was observed with other wide-type strains or common intestinal pathogens, ensuring the exclusive detection of the EMPY vaccine strain. Weekly testing over 3 weeks demonstrated minimal variability, indicating robust consistency in the method's application. Testing on 61 clinical samples revealed a 57.38% positivity rate for species and 13.11% for the vaccine strain. The Em_marker6 gene exhibited genetic stability across multiple generations, confirming the detection method's robust stability for the attenuated vaccine strain. This study significantly advances the field of avian coccidiosis research and control by providing a valuable tool for monitoring vaccine purity and preventing inadvertent infections in vaccinated flocks, aligning with global efforts to curb antibiotic use in animal feed.
PubMed: 38840634
DOI: 10.3389/fvets.2024.1397166 -
Emerging Microbes & Infections Dec 2024Recently, an outbreak of highly pathogenic avian influenza A (H5N1), which carries the clade 2.3.4.4b hemagglutinin (HA) gene and has been prevalent among North American...
Recently, an outbreak of highly pathogenic avian influenza A (H5N1), which carries the clade 2.3.4.4b hemagglutinin (HA) gene and has been prevalent among North American bird populations since the winter of 2021, was reported in dairy cows in the United States. As of 24 May 2024, the virus has affected 63 dairy herds across nine states and has resulted in two human infections. The virus causes unusual symptoms in dairy cows, including an unexpected drop in milk production, and thick colostrum-like milk. Notably, The US Food and Drug Administration reported that around 20% of tested retail milk samples contained H5N1 viruses, with a higher percentage of positive results from regions with infected cattle herds. Data are scant regarding how effectively pasteurization inactivates the H5N1 virus in milk. Therefore, in this study, we evaluated the thermal stability of the H5 clade 2.3.4.4b viruses, along with one human H3N2 virus and other influenza subtype viruses, including H1, H3, H7, H9, and H10 subtype viruses. We also assessed the effectiveness of pasteurization in inactivating these viruses. We found that the avian H3 virus exhibits the highest thermal stability, whereas the H5N1 viruses that belong to clade 2.3.4.4b display moderate thermal stability. Importantly, our data provide direct evidence that the standard pasteurization methods used by dairy companies are effective in inactivating all tested subtypes of influenza viruses in raw milk. Our findings indicate that thermally pasteurized milk products do not pose a safety risk to consumers.
Topics: Animals; Pasteurization; Milk; Cattle; Influenza A Virus, H5N1 Subtype; Humans; Influenza in Birds; Virus Inactivation; United States; Influenza, Human; Influenza A virus; Female
PubMed: 38832658
DOI: 10.1080/22221751.2024.2364732 -
One Health (Amsterdam, Netherlands) Jun 2024Wildlife disease surveillance, particularly for pathogens with zoonotic potential such as Highly Pathogenic Avian Influenza Virus (HPAIV), is critical to facilitate...
Wildlife disease surveillance, particularly for pathogens with zoonotic potential such as Highly Pathogenic Avian Influenza Virus (HPAIV), is critical to facilitate situational awareness, inform risk, and guide communication and response efforts within a One Health framework. This study evaluates the intensity of avian influenza virus (AIV) surveillance in Ontario's wild bird population following the 2021 H5N1 incursion into Canada. Analyzing 2562 samples collected between November 1, 2021, and October 31, 2022, in Ontario, Canada, we identify spatial variations in surveillance intensity relative to human population density, poultry facility density, and wild mallard abundance. Using the spatial scan statistic, we pinpoint areas where public engagement, collaborations with Indigenous and non-Indigenous hunter/harvesters, and working with poultry producers, could augment Ontario's AIV wild bird surveillance program. Enhanced surveillance at these human-domestic animal-wildlife interfaces is a crucial element of a One Health approach to AIV surveillance. Ongoing assessment of our wild bird surveillance programs is essential for strategic planning and will allow us to refine approaches and generate results that continue to support the program's overarching objective of safeguarding the health of people, animals, and ecosystems.
PubMed: 38832079
DOI: 10.1016/j.onehlt.2024.100760 -
The Journal of Infection Jun 2024
PubMed: 38830409
DOI: 10.1016/j.jinf.2024.106193 -
PloS One 2024The rapid spread of highly pathogenic avian influenza (HPAI) A (H5N1) viruses in Southeast Asia in 2004 prompted the New Zealand Ministry for Primary Industries to...
The rapid spread of highly pathogenic avian influenza (HPAI) A (H5N1) viruses in Southeast Asia in 2004 prompted the New Zealand Ministry for Primary Industries to expand its avian influenza surveillance in wild birds. A total of 18,693 birds were sampled between 2004 and 2020, including migratory shorebirds (in 2004-2009), other coastal species (in 2009-2010), and resident waterfowl (in 2004-2020). No avian influenza viruses (AIVs) were isolated from cloacal or oropharyngeal samples from migratory shorebirds or resident coastal species. Two samples from red knots (Calidris canutus) tested positive by influenza A RT-qPCR, but virus could not be isolated and no further characterization could be undertaken. In contrast, 6179 samples from 15,740 mallards (Anas platyrhynchos) tested positive by influenza A RT-qPCR. Of these, 344 were positive for H5 and 51 for H7. All H5 and H7 viruses detected were of low pathogenicity confirmed by a lack of multiple basic amino acids at the hemagglutinin (HA) cleavage site. Twenty H5 viruses (six different neuraminidase [NA] subtypes) and 10 H7 viruses (two different NA subtypes) were propagated and characterized genetically. From H5- or H7-negative samples that tested positive by influenza A RT-qPCR, 326 AIVs were isolated, representing 41 HA/NA combinations. The most frequently isolated subtypes were H4N6, H3N8, H3N2, and H10N3. Multivariable logistic regression analysis of the relations between the location and year of sampling, and presence of AIV in individual waterfowl showed that the AIV risk at a given location varied from year to year. The H5 and H7 isolates both formed monophyletic HA groups. The H5 viruses were most closely related to North American lineages, whereas the H7 viruses formed a sister cluster relationship with wild bird viruses of the Eurasian and Australian lineages. Bayesian analysis indicates that the H5 and H7 viruses have circulated in resident mallards in New Zealand for some time. Correspondingly, we found limited evidence of influenza viruses in the major migratory bird populations visiting New Zealand. Findings suggest a low probability of introduction of HPAI viruses via long-distance bird migration and a unique epidemiology of AIV in New Zealand.
Topics: Animals; New Zealand; Influenza in Birds; Animals, Wild; Birds; Phylogeny; Influenza A virus; Hemagglutinin Glycoproteins, Influenza Virus; Genome, Viral; Ducks
PubMed: 38829903
DOI: 10.1371/journal.pone.0303756 -
Emerging Microbes & Infections Dec 2024Europe has suffered unprecedented epizootics of high pathogenicity avian influenza (HPAI) clade 2.3.4.4b H5N1 since Autumn 2021. As well as impacting upon commercial and...
Europe has suffered unprecedented epizootics of high pathogenicity avian influenza (HPAI) clade 2.3.4.4b H5N1 since Autumn 2021. As well as impacting upon commercial and wild avian species, the virus has also infected mammalian species more than ever observed previously. Mammalian species involved in spill over events have primarily been scavenging terrestrial carnivores and farmed mammalian species although marine mammals have also been affected. Alongside reports of detections of mammalian species found dead through different surveillance schemes, several mass mortality events have been reported in farmed and wild animals. In November 2022, an unusual mortality event was reported in captive bush dogs () with clade 2.3.4.4b H5N1 HPAIV of avian origin being the causative agent. The event involved an enclosure of 15 bush dogs, 10 of which succumbed during a nine-day period with some dogs exhibiting neurological disease. Ingestion of infected meat is proposed as the most likely infection route.
Topics: Animals; Influenza A Virus, H5N1 Subtype; United Kingdom; Animals, Wild; Orthomyxoviridae Infections; Canidae; Influenza in Birds
PubMed: 38828793
DOI: 10.1080/22221751.2024.2361792 -
Archives of Razi Institute Dec 2023Influenza viruses can multiply in quails and be transmitted to other animal species. As vaccination reduces virus shedding in chickens, the effect of the killed H9N2...
Influenza viruses can multiply in quails and be transmitted to other animal species. As vaccination reduces virus shedding in chickens, the effect of the killed H9N2 avian influenza virus (AIV) on tissue distribution and virus shedding was evaluated in quails. One hundred 20-day-old quails were divided into six equal groups, kept in separate pens, and fed ad libitum. Before vaccination, blood samples were randomly collected from the wing veins. Four groups were vaccinated with the inactivated H9N2 Razi Institute vaccine at 21 days subcutaneously at the back of neck. Three weeks later, two groups were re-vaccinated. Two weeks later, at the age of 56 days, three groups were challenged with 100 μL of allantoic fluid containing 10 EID H9N2 through the oculonasal route. Blood samples were collected from quails at 42, 56, 63, and 70 days from each group to determine AIV antibodies by the hemagglutination inhibition test. Three quails were randomly selected and euthanized from each group on days 1, 3, and 6 post-inoculation (PI). Tissue samples were collected, and the RT-PCR test was performed. No clinical signs or gross lesions existed in any of the groups during the experiment. However, the virus was detected in different tissues on the first, third, and sixth days after the challenge in unvaccinated challenged birds. Virus detection was significantly more frequent in the quails vaccinated once and challenged than in the twice-vaccinated challenged group (≤0.05). On the third day of PI, the virus was detected in some organs of the challenged groups. On the sixth day of PI, the virus was detected only in the lungs of two unvaccinated and once-vaccinated challenged birds. It was concluded that the vaccination of quails against AIV H9 is necessary to protect them from clinical signs, as well as respiratory tract and intestine replication. Two-time vaccination significantly protects the respiratory and intestine tracts, compared to one-time vaccination (≤0.05).
Topics: Animals; Influenza A Virus, H9N2 Subtype; Influenza in Birds; Influenza Vaccines; Coturnix; Vaccination; Virus Shedding; Vaccines, Inactivated; Poultry Diseases; Antibodies, Viral
PubMed: 38828164
DOI: 10.32592/ARI.2023.78.6.1746