Search Results (112)

Background: Infectious bronchitis virus (IBV) is a gammacoronavirus that causes a highly contagious disease in chickens and seriously endangers the poultry industry. The GI-19 is a predominant lineage. However, no effective commercially available vaccines against this virus are available. Methods: In this present study, the CHO eukaryotic and the E.coli prokaryotic expression system were used to express S1-SpyTag and AP205-SpyCatcher, respectively. Subsequently, the purified S1-SpyTag and AP205-SpyCatcher were coupled to form the nanoparticles AP205-S1 (nAP205-S1) in PBS buffer at 4 °C for 48 h. S1-SpyTag and nAP205-S1 were formulated into vaccines with white oil adjuvant and employed to immunize 1-day-old SPF chickens for the comparative evaluation of their immune efficacy. Results: The nAP205-S1 vaccine in chickens induced robust IBV-specific humoral and cellular immune responses in vivo. Importantly, the humoral and cellular immune responses elicited by the nAP205-S1 vaccine were more robust than those induced by the IBV S1-SpyTag vaccine at both the same dose and double the dose, with a notably significant difference observed in the cellular immune response. Furthermore, experimental data revealed that chicken flocks vaccinated with nAP205-S1 achieved 100% group protection following a challenge, exhibiting a potent protective immune response and effectively inhibiting viral shedding. Conclusions: These results reveal the potential of developing a novel nanoparticle vaccine with broadly protective immunity against GI-19 IBV. Full article

Infectious bursal disease (IBD) is a viral disease that most commonly affects young chickens and destroys lymphocytes, leading to immunosuppression. The field study aimed to investigate the effect of three different vaccines administered in ovo against IBD and spray against Newcastle disease (ND) on serological response tested for IBD and ND and histopathological analysis of the bursa of Fabricius (BF) and quantitative B lymphocytes in BF in broiler chickens. The study was conducted on a farm of four hen houses with 30,000 chicks in each building. Three different vaccination programs were used in the poultry hatchery, and one hen house IV was not vaccinated. All three groups were vaccinated at 18 days and 9 h in ovo during egg transfer against IBD at a dose of 0.05 mL/embryo, group I vector vaccine (strain vHVT013-69), group II immunocomplex vaccine (strain Winterfield 2512), group III immunocomplex vaccine (strain M.B, 0.05). Then, after hatching, the chicks were vaccinated in a spray (groups I, II, and III) against NDV (strain VG/GA, 20 mL/100 birds) and infectious bronchitis (IBV) in a spray (strain H-120, serotype Mass, and strain CR88121, serotype 793B) at a dose of 20 mL/100 chicks. On days 1, 21, 31, and 41, blood was collected for serological tests to determine the antibody titer against IBD, which was performed using two tests (IDEXX and ID-Vet) and against ND. During the necropsy of birds on days 21 and 31, the bursae of Fabricius were collected from five chickens for histopathological evaluation of BF and quantitative B lymphocyte counts; a total of 40 bursae were analyzed (10 per group). The vaccination program applied significantly (p < 0.05) affected the immune response expressed as a geometric mean titer (GMT) in the serum of the examined chickens against IBDV on days 21, 31, and 41. Differences were also demonstrated in the mass and level of BF damage and the number of B lymphocytes. No significant differences were demonstrated in the GMT in the serum of the examined chickens against NDV depending on the vaccination program applied. Full article

Infectious bronchitis virus (IBV) and low-pathogenic avian influenza virus (LPAIV) H9N2 are commonly identified in poultry, individually or in association with other pathogens. This study monitored 183 broiler farms affected by respiratory diseases across seven regions of Morocco from January 2021 to December 2023. Among these farms, 87.98% were vaccinated against IBV, while 57.92% were against AI H9N2. Abnormally high mortality rates were observed in 44.26% of the farms, with 24.69% of cases attributed to IBV, 50.62% to LPAI H9N2, and 13.58% due to coinfection with both IBV and H9N2. RT-PCR analysis of tissue samples and cloacal and tracheal swabs collected from 183 broiler farms revealed that 33.33% were positive for IBV and 34.97% for H9N2. Coinfection by IBV and H9N2 was detected in 12.57% of cases, peaking at 17% in 2022. Co-infected flocks exhibited severe clinical signs and lesions, such as reduced food consumption, diarrhea, and renal issues. The predominant lesions were in the respiratory tract, affecting 91.26% of infected broilers. Additionally, among the 183 flocks, 50 farms that tested positive for IBV infection were randomly selected from the seven regions of Morocco for further investigation of other respiratory pathogens, including Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS), and infectious laryngotracheitis (ILT), using real-time RT-PCR. Detection rates for these pathogens were 26% for MG, 30% for MS, 4% for ILTv (vaccine strain), and 18% for ILTw (wild strain). Detection rates for single, dual, triple, and quadruple infections were 34%, 42%, 18%, and 4%, respectively. The most common dual and triple coinfections were IBV + H9N2 (14%) and IBV + MG + MS (10%). Phylogenetic analysis of the S gene identified two main IBV genotypes, namely, 793B and D181, with the latter being a strain circulating for the first time in Moroccan poultry. This underscores the urgent need to establish surveillance systems to track pathogen circulation and implement strategies to control virus spread, ensuring the protection of animals and public health. Full article

Infectious bronchitis virus (IBV) is a coronavirus first isolated in the 1930s infecting chickens. IBV causes great economic losses to the global poultry industry, as it affects egg production and causes mortality by leaving the host susceptible to secondary bacterial infections. Even though vaccines are available, they are poorly cross-protective against new variants of the virus, which are always on the cusp of emerging. Effective antiviral therapies, or possibly the production of transgenic animals immune to IBV infection, are therefore sorely needed. As the papain-like protease (PLpro) of IBV has deubiquitinating activity besides its crucial ability to cleave the viral polyprotein, we have applied a novel strategy of selecting ubiquitin variants (UbVs) from a phage-displayed library that have high affinity to this viral protease. These UbVs were found to inhibit the deubiquitinating activity of PLpro and consequently obstruct the virus’s ability to evade the innate immune response in the host cell. By obstructing the proteolytic activity of PLpro, these UbVs were seemingly able to inhibit viral infection as assessed using immunofluorescence microscopy. Whilst virus infection was detected in around 5% of UbV-expressing cells, the virus was present in around 30–40% of GFP (control)-expressing cells. This suggests that the expression of UbVs indeed seems to inhibit IBV infection, making UbVs a potentially potent and innovative antiviral strategy in the quest for control of IBV infections. Full article

Background: Live attenuated and inactivated virus vaccines are commonly used against infectious bronchitis virus (IBV) in chickens, but they have limitations such as mutation risks and short efficacy. This study explores cationic bovine serum albumin (BSA) polyamine nanoparticles (NPs) for delivering IBV spike protein mRNA, aiming to develop a safer and more effective vaccine. Methods: A BSA-based nanoparticle system was designed with positive surface charges and characterized using dynamic light scattering (DLS), Zetasizer, and transmission electron microscopy (TEM). Its cytotoxicity, cellular uptake, and ability to deliver IBV spike protein mRNA were evaluated in macrophage-like chicken cell lines (HD11), followed by immunogenicity studies in SPF chickens to assess immune responses. Results: The study demonstrated successful binding and transfection efficiency of the in vitro transcription (IVT)-mRNA complexed with the NPs, which was enhanced with chloroquine. Immunogenicity studies in SPF chickens showed a significant increase in antibody titers in chickens vaccinated with the mRNA vaccine compared to the PBS control, indicating an effective immune response against the IBV S protein. Furthermore, the neutralization index doubled after a higher-dose mRNA booster with chloroquine, and PBMCs from immunized chickens exhibited a threefold higher stimulation index than the PBS control. Conclusions: BSA-based NPs effectively deliver IBV spike protein mRNA, enhancing immune responses and offering a promising strategy for a safer, more effective IBV vaccine. Full article

Infectious bronchitis virus (IBV) is a chicken pathogen present in commercial poultry farms worldwide. It is classified within the species Avian coronavirus, genus Gammacoronavirus. As with other members of the family Coronaviridae, it has a single positive-sense RNA genome with 27.6 Kb and presents viral particles with a typical crown-like aspect due to the spike (S) transmembrane glycoprotein. IBV has a remarkable capacity for genetic recombination and mutation, resulting in many genotypes and antigenic variants over evolutionary time. Currently, it is classified into nine genetic types (GI to GIX) and 41 (1 to 41) lineages disseminated worldwide. In South America, IBV was first identified in early commercial poultry production ventures in Brazil in the 1950s. Since then, this virus has been frequently detected in commercial South American poultry farms, being classified into serotypes in the first decades and genotypes more recently. IBVs of the Massachusetts (Mass) serotype were initially detected and vaccine strains of this serotype were used extensively on commercial poultry farms. Other serotypes/genotypes were identified later, with almost all of them classified in the current genetic type I (GI). In addition, five GI lineages (GI-1, -11, -13, -16, and -23) have been associated with the main infectious bronchitis outbreaks in the continent, with some variations in the occurrence according to the countries and the period of time. Molecular epidemiological surveillance of IBV genetic types and lineages is necessary to anticipate potential outbreaks, revealing patterns of viral evolution and dissemination, as well as to guide the selection of appropriate vaccine strains and immunization programs. Full article

Background: Influenza remains a global health challenge, causing significant morbidity and mortality. This study explores the epidemiology of influenza A (IAV) and B (IBV) during the 2021–2023 winter seasons within a targeted Jordanian subpopulation to inform public health strategies. Methods: Nasopharyngeal swabs from patients with acute respiratory tract infections (ARTIs) in three major Jordanian cities were analyzed. RT-PCR was utilized to detect common respiratory pathogens, and specific primers identified IAV (H1N1) pdm09, H3N2, and IBV subtypes. Statistical analyses examined influenza subtype frequencies and their association with demographics and coinfection patterns. Results: IAV, IBV, and ICV were detected in 9.4%, 13.5%, and 5.5% of cases, respectively. Predominant strains were IAV (H1N1) pdm09 (55.8%), H3N2 (30.2%), and IBV Victoria lineage (98.4%). Coinfections with IAV frequently involved Bordetella spp., Staphylococcus aureus, and IBV, while IBV also showed coinfections with Haemophilus influenzae type B and IAV. Conclusions: The predominance of IAV (H1N1) pdm09 and IBV Victoria lineage highlights the need for strain-specific vaccination. Frequent coinfections underscore the importance of comprehensive diagnostics. Local public health strategies should focus on increasing vaccine coverage and preventive education, especially for adults and urban populations. Full article

Avian infectious bronchitis is caused by the avian infectious bronchitis virus (IBV), which poses a significant threat to the poultry industry and public health. The S1 protein of IBV plays a crucial role in the process of the virus invading host cells. To investigate the significant antigenic targets within the S1 protein, in this study, the truncated S1 sequence of the IBV M41 strain was cloned with approximately 660 bp and expressed. After purification and renaturation, the recombinant S1 protein was immunized into BALB/c mice. Then, following fusion with lymphocytes and SP2/0 cells, the indirect ELISA and Western blotting techniques were employed to screen hybridoma cell lines secreting monoclonal antibodies (mAbs) targeting the S1 protein. Antigenic epitopes of the mAbs were identified using truncated S1 fragments and peptide scanning. The results indicated that three hybridoma cell lines stably secreting S1 protein-specific mAbs (2A10, 4E9, and 5E12) were screened. The heavy chains of the three mAbs were IgG1, and all three mAbs contained kappa light chains. The identified minimal B-cell epitopes were ¹³²RVSAMK¹³⁷ and ¹⁴²FYNLTV¹⁴⁷. Homology analysis showed these both epitopes were conserved across IBV subtypes and located on the S1 protein surface. The conserved β-sheet epitope ¹³²RVSAMK¹³⁷ and the surface-exposed, flexible loop epitope ¹⁴²FYNLTV¹⁴⁷ serve as ideal targets for broad-spectrum diagnostics and early infection detection, respectively. These epitopes provide unique structural advantages for antibody binding, enabling the design of multivalent epitope vaccines or the development of immunomodulatory drugs. They offer novel biomaterials and targets for antibody-based drug development and rapid detection methods for avian infectious bronchitis virus (IBV), holding significant potential for the prevention and control of IBV. Full article

Infectious bronchitis virus (IBV) poses a significant threat to poultry worldwide, necessitating robust surveillance and vaccination strategies. This study aimed to conduct IBV surveillance in Brazil, assess potential vaccine viral escapes, and evaluate vaccine persistence in vaccinated broilers. A total of 1000 tracheal swabs from 100 flocks across six states were analyzed using RT-PCR. The results showed that 91% of the flocks tested positive for IBV. The detected strains included GI-1, GI-11, and GI-23. Notably, 90% of batches received vaccines containing either GI-1 or GI-11 lineages. The study revealed vaccine persistence in 67 samples between days 16 and 32 post-vaccination. In contrast, unvaccinated batches had a high prevalence of IBV GI-11 strains (70%). These findings highlight widespread IBV circulation in Brazil with persistent viral presence in vaccinated birds and wild viruses in unvaccinated ones. Collectively, the data reveal a widespread presence of IBV in Brazil, characterized by prolonged viral persistence in vaccinated animals and the occurrence of wild viruses in both unvaccinated birds and those vaccinated against specific strains. It can be concluded from this study that there was a widespread occurrence of IBV in Brazil, providing long viral persistence in vaccinated animals, as well as the occurrence of wild virus in unvaccinated birds or birds vaccinated against individual strains. Full article

Despite annual vaccines, Influenza B viruses (IBVs) continue to cause severe infections and have a significant impact and burden on the healthcare system. Improving IBV vaccine effectiveness is a key focus, with various strategies under investigation. In this research, we used a computational design to select wildtype sequences for a multivalent viral-vectored vaccine (rAd-Tri-Vic) targeting the Victoria-like (Vic) hemagglutinin (HA) protein. In mouse models, the vaccine induced strong antibody and T cell responses, providing complete protection against both lineage-specific and cross-lineage (Yamagata-like) lethal challenges. The immune responses remained robust for up to six months, which demonstrated sustained protection. These results highlight the potential of HA-targeted multivalent vaccines to enhance the IBV efficacy and address protection against antigenically diverse IBV strains. Full article

Background: During the COVID-19 pandemic, we continuously monitored the epidemiology of influenza virus among pediatric patients from January 2021 to December 2023 in Hainan Island, China. Methods: In this study, we collected 54,974 nasopharyngeal swab samples for influenza A Virus (IAV) testing and 53,151 samples for influenza B Virus (IBV) testing from pediatric outpatients. Additionally, we also collected 19,687 nasopharyngeal swab samples from pediatric inpatients for IAV and IBV testing. Outpatient samples were screened for influenza viruses (IVs) infection by the colloidal gold method. Targeted Next-Generation Sequencing (tNGS) was used to detect influenza virus infections in inpatients. Influenza virus types were identified by analyzing the HA/NA partial regions. Results: The findings revealed a significant decrease in the infection rate of IBV over the specified period, while the infection rate of IAV exhibited a rising trend. Additionally, B/Victoria lineage was the dominant epidemic strain in 2021, while the epidemic strains in 2022 and 2023 underwent a dynamic transformation from A/H3N2 to A/H1N1. Phylogenetic analysis revealed close relationships among the circulating strains. Nonetheless, because the sample size is limited, additional research is required. Conclusions: Our findings suggest that the predominant types of influenza viruses in the pediatric population are undergoing dynamic changes, influenced by the implementation and relaxation of non-pharmaceutical intervention measures. These findings highlight the need for adaptive influenza vaccination and containment strategies, particularly in tropical regions like Hainan, where climate and public health policies significantly impact viral transmission patterns. The insights gained from this study could inform more effective public health strategies in similar regions to mitigate the impact of influenza outbreaks in the future. Full article

Background/Objectives: Despite decades of extensive vaccinations against avian infectious bronchitis virus (IBV) infection, outbreaks caused by constantly emerging variants due to genome recombination between different viral strains, including vaccine strains, occur annually worldwide. The development of novel vaccines with favorable safety and effectiveness is required but is hindered by a limited understanding of vaccination against IBV. Methods: Here, we performed a comprehensive analysis of the in vivo dynamics of peripheral blood mononuclear cells (PBMCs) in specific pathogen-free chickens inoculated with the widely used live attenuated IBV vaccine strain H120 at single-cell level, using high-throughput single-cell transcriptome sequencing (scRNA-seq). Results: High-quality sequencing dataset for four scRNA-seq data containing the transcriptomes of 29,846 individual chicken PBMCs were obtained, defining 22 populations and 7 cell types based on distinct molecular signatures and known markers. Further integrative analysis constructed the time series dynamic cell transition and immune response landscapes within the two weeks post-prime vaccination against IBV. Enhanced crosstalk between antigen-presenting cells and T lymphocytes was revealed as early as four days post-vaccination. The specific immune cell populations and their comprehensive cellular and molecular networks involved in the initiation phase of antiviral adaptive immune responses were elucidated in details. Conclusions: Our study provides a comprehensive view of the dynamic initiation of immune responses in chickens against IBV infection at the cellular and molecular levels, which provides theoretical support and potential solutions for the future rational design of safe and effective vaccines, the augmentation of the efficacy of current vaccines, and the optimization of immune programs. Full article

Background: Polypeptide vaccines have the potential to improve immune responses by targeting conserved and weakly immunogenic regions in antigens. This study aimed to identify and evaluate the efficacy of a novel influenza universal vaccine candidate consisting of multiple polypeptides derived from highly conserved regions of influenza virus proteins hemagglutinin (HA), neuraminidase (NA), and matrix protein 2 (M2). Methods: Immunoinformatics tools were used to screen conserved epitopes from different influenza virus subtypes (H1N1, H3N2, H5N1, H7N9, H9N2, and IBV). A polypeptide vaccine, P125-H, was constructed by linking multiple epitopes using Ii-Key technology. The immunogenicity of P125-H was assessed in mice using MF59-adjuvanted P125-H via intraperitoneal injection. Hemagglutination inhibition (HI) and neutralizing antibody responses were measured, along with IFN-γ levels in spleen lymphocytes. Protective efficacy was evaluated using viral challenge with lethal doses of H1N1 and H7N9. Results: Mice immunized with P125-H generated high levels of HI and neutralizing antibodies against multiple influenza strains. IFN-γ production was significantly elevated in spleen lymphocytes upon stimulation with the vaccine. P125-H protected mice from influenza infection, reducing weight loss and the viral load in the lungs, mitigating lung pathology, and decreasing mortality. Conclusions: The P125-H vaccine induced broad cross-protection against multiple influenza strains and elicited robust immune responses. It demonstrates strong potential as a candidate for a universal influenza vaccine. Full article

Background/Objectives: Infectious bronchitis (IB) is a highly infectious avian disease caused by the infectious bronchitis virus (IBV). The disease causes lesions mainly in the respiratory, reproductive, and renal systems and has a significant economic impact on the poultry industry worldwide. Methods: We discovered two unique IBV isolates (T-62: PP737794.1 and CL-61: PP783617.1) circulating in Canada and molecularly characterized them. Results: The phylogenetic analysis revealed that the IBV isolates belong to genotype I and fall between lineages 25 and 7. Further analysis of the T-62 IBV isolate indicated that it is a potential recombinant of the Iowa state isolate (IA1162/2020-MW) and that the CL-61 strain of the IBV is also a recombinant IBV with the Connecticut (Conn) vaccine strain as its major parent. The S1 glycoprotein of the CL-61 and T-62 strains of the IBV had 85.7% and 73.2% amino acid (aa) identities respectively compared to the Conn vaccine strain. There were 67 and 129 aa substitutions among the S1 glycoprotein of the CL-61 and T-62 strains of the IBV compared to the Conn vaccine, respectively. Importantly, two and nineteen of these aa variations were in hypervariable regions 1 (HVR1) and HVR3. Finally, the two IBV isolates possessed a higher affinity for the sialic acid ligand compared to the DMV/1639 and Mass/SES IBV strains. Conclusions: Genetic recombination in the IBV results in the continual emergence of new variants, posing challenges for the poultry industry. As indicated by our analyses, live attenuated vaccine strains play a role in the genetic recombination of the IBV, resulting in the emergence of variants. Full article

Infectious Bronchitis Virus (IBV) is a major threat to the poultry industry worldwide, causing significant economic losses. While the virus’s genetic structure is well understood, the specific strains circulating in Bolivia have remained uncharacterized until now. This study aimed to identify and characterize new IBV strains in Bolivia. Tissue samples from broilers exhibiting clinical signs of Infectious Bronchitis were screened to detect IBV using real-time RT-PCR (RT-qPCR). Positive samples with low cycle threshold (Ct) values were selected for sequencing the full S1 gene. Of the 12 samples analyzed, 10 were determined to be positive for IBV. However, only four samples yielded sufficient genetic material for sequencing and subsequent phylogenetic analysis. The results revealed the presence of GI-1 and GI-23 lineages, both belonging to genotype I (GI). The GI-1 lineage showed >99% sequence identity to the H120 and Massachusetts vaccine strains, suggesting a close relationship. In contrast, the GI-23 lineage clustered with other IBV strains, showing a distinct subclade that is genetically distant from Brazilian strains. No evidence of recombination was found. Furthermore, amino acid substitution analysis identified specific mutations in the S1 subunit, particularly in the hypervariable regions 1, 2, and 3. These mutations could potentially alter the virus’s antigenicity, leading to reduced vaccine efficacy. The findings of this study highlight the importance of continued and broad genomic surveillance of circulating IBV strains and the need to improve vaccination strategies in Bolivia. Full article