Infectious Bursal Disease Research Articles

Identification of the main genetic clusters of avian reoviruses from a global strain collection.

Avian reoviruses (ARV), an important pathogen of poultry, have received increasing interest lately due to their widespread occurrence, recognized genetic diversity, and association to defined disease conditions or being present as co-infecting agents. The efficient control measures require the characterization of the available virus strains. The present study describes an ARV collection comprising over 200 isolates from diagnostic samples collected over a decade from 34 countries worldwide. One hundred and thirty-six ARV isolates were characterized based on σC sequences. The samples represented not only arthritis/tenosynovitis and runting-stunting syndrome, but also respiratory symptoms, egg production problems, and undefined disease conditions accompanied with increased mortality, and were obtained from broiler, layer or breeder flocks. In 31 percent of the cases other viral or bacterial agents were demonstrated besides ARV. The most frequent co-infectious agent was infectious bronchitis virus followed by infectious bursal disease virus and adenoviruses. All isolates could be classified in one of the major genetic clusters, although we observed marked discrepancies in the genotyping systems currently in use, a finding that made genotype assignment challenging. Reovirus related clinical symptoms could not be unequivocally connected to any particular virus strains belonging to a specific genetic group, suggesting the lack of strict association between disease forms of ARV infection and the investigated genetic features of ARV strains. Also, large genetic differences were seen between field and vaccine strains. The presented findings reinforce the need to establish a uniform, widely accepted molecular classification scheme for ARV and further, highlight the need for ARV strain identification to support more efficient control measures.

Pathological and Molecular Study of Infectious Bursal Disease in Commercial Chicken

A total of 100 Poultry carcasses suspected for infectious bursal disease were collected from 20 poultry farms and conducted postmortem at the Department of Veterinary Pathology, NTR College of Veterinary science, Gannavaram ( Andra Pradesh , India) . Sick birds showed ruffled feathers, loss of appetite, whitish diarrhea and soiled vent. On postmortem examination, grossly bursa of Fabricius was swollen, enlarged with mucous exudate in lumen and haemorrhages were noticed on the mucosa. Paint brush haemorrhages were noticed on thigh muscles and at the junction of gizzard and proventriculus. Kidneys were swollen and ureters were filled with urate crystals. Histopathology of bursa of Fabricius revealed shrinkage of follicles, severe lymphoid depletion, necrosis, lymphocytolysis and cyst formation in follicles. Diagnosis of the disease was confirmed by targeting the VP2 gene of infectious bursal disease virus (IBDV) with a reverse transcriptase polymerase chain reaction which revealed an amplicon size of 743bp. Based on gross and histopathological lesions and molecular findings disease was confirmed as infectious bursal disease.

Green Synthesis of Silver Nanoparticles with Extract of Indian Ginseng and In Vitro Inhibitory Activity against Infectious Bursal Disease Virus

Infectious bursal disease virus (IBDV) is a serious poultry pathogen responsible for causing major economic losses to the poultry industry globally. The virus is closely related to several other important viral pathogens of fishes, crabs, and mollusks and evolutionarily related to important viral pathogens of humans. Previously, we demonstrated the inhibition of this virus by the extracts of roots of Withania somnifera Dunal, commonly known as Indian ginseng, both in vitro and in vivo. Furthermore, many studies reported the inhibition of diverse types of viruses by nanoparticles of silver. In the present study, we investigated the inhibitory effect of silver nanoparticles obtained by green synthesized with Indian ginseng extract against IBDV. Conditions for the synthesis of silver nanoparticles were optimized, and the nanoparticles thus obtained (WS AgNPs) were characterized physically. Thereafter, the maximum non-cytotoxic dose of these nanoparticles for treating chicken embryo fibroblasts (CEF) was determined. Treatment of IBDV-infected CEF with the WS AgNPs decreased the infective virus titer by >93%, intracellular viral load by >71%, and virus-induced cytopathy by >51%, demonstrating the strong inhibitory effect of the WS AgNPs against IBDV, and encouraging similar applications against related veterinary and human viruses.

Phosphorylation of VP1 Mediated by CDK1-Cyclin B1 Facilitates Infectious Bursal Disease Virus Replication.

Infectious bursal disease virus (IBDV) is a double-stranded RNA (dsRNA) virus belonging to the genus Avibirnavirus in the family Birnaviridae. It can cause serious failure of vaccination in young poultry birds with impaired immune systems. Post-translational modifications of the VP1 protein are essential for viral RNA transcription, genome replication, and viral multiplication. Little information is available so far regarding the exact mechanism of phosphorylation of IBDV VP1 and its significance in the viral life cycle. Here, we provide several lines of evidence that the cyclin-dependent kinase 1 (CDK1)-cyclin B1 complex phosphorylates VP1, which facilitates viral replication. We show that the CDK1-cyclin B1 specifically interacts with VP1 and phosphorylates VP1 on the serine 7 residue, located in the N-terminal 7SPAQ10 region, which follows the optimal phosphorylation motif of CDK1, p-S/T-P. Additionally, IBDV infection drives the cytoplasmic accumulation of CDK1-cyclin B1, which co-localizes with VP1, supporting the kinase activity of CDK1-cyclin B1. Treatment with CDK1 inhibitor RO3306 and knockdown of CDK1-cyclin B1 severely disrupts the polymerase activity of VP1, resulting in diminished viral replication. Moreover, the replication of S7A mutant recombinant IBDV was significantly decreased compared to that of wild-type (WT) IBDV. Thus, CDK1-cyclin B1 is a crucial enzyme which phosphorylates IBDV VP1 on serine 7, which is necessary both for the polymerase activity of VP1 and for viral replication. IMPORTANCE Infectious bursal disease virus still poses a great economic threat to the global poultry farming industry. Detailed information on the steps of viral genome replication is essential for the development of antiviral therapeutics. Phosphorylation is a common post-translational modification in several viral proteins. There is a lack of information regarding the significance of VP1 phosphorylation and its role in modulating the viral life cycle. In this study, we found that CDK1-cyclin B1 accumulates in the cytoplasm and phosphorylates VP1 on serine 7. The presence of a CDK1 inhibitor and the silencing of CDK1-cyclin B1 decrease IBDV replication. The mutation of VP1 serine 7 to alanine reduces VP1 polymerase activity, disrupting the viral life cycle, which suggests that this residue serves an essential function. Our study offers novel insights into the regulatory mechanism of VP1 phosphorylation.

An Infectious Bursal Disease Virus (IBDV) Reverse Genetics Rescue System and Neutralization Assay in Chicken B Cells

Infectious bursal disease virus (IBDV) is a major threat to the productivity of the poultry industry due to morbidity, mortality, and immunosuppression that exacerbates secondary infections and reduces the efficacy of vaccination programs. Field strains of IBDV have a preferred tropism for chicken B cells, the majority of which reside in the bursa of Fabricius (BF). IBDV adaptation to adherent cell culture is associated with mutations altering amino acids in the hypervariable region (HVR) of the capsid protein, which affects immunogenicity and virulence. Until recently, this has limited both the application of reverse genetics systems for engineering molecular clones, and the use of in vitro neutralization assays, to cell-culture-adapted strains of IBDV. Here, we describe the rescue of molecular clones of IBDV containing the HVR from diverse field strains, along with a neutralization assay to quantify antibody responses against the rescued viruses, both using chicken B cells. These methods are readily adaptable to any laboratory with molecular biology expertise and negate the need to obtain wild-type strains. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: A chicken B-cell rescue system for IBDV Basic Protocol 2: A chicken B-cell neutralization assay for IBDV.

A review of the Infectious Bursal Disease (IBD) in Iran

Infectious bursal disease (IBD) is one of the most important diseases in the poultry industry all over the world. It is a viral disease caused by a birnavirus, which weakens the immune system. The disease was observed for the first time in 1962 in the Gumboro area of ​​Delaware, USA. The first report of this disease in Iran dates back to 1994. Since then, various investigations have been conducted in Iran on the isolation and identification of IBDV isolates, cognitive immunological studies and vaccine testing and design, disease pathogenesis and pathology, and recently in the field of genetic engineering. The main procedure for IBD control is vaccination in productive and commercial herds. Therefore, studies related to vaccination and immunogenicity play an essential role in designing preventive measures against this disease. In this manuscript, a comprehensive review of the studies conducted in Iran on IBD has been discussed.

Efficacy of different live infectious bursal disease vaccines on antibodies to infectious bursal disease virus and Newcastle disease vaccine La Sota in ISA brown chicks

Aim: In this study, the efficacy of five commercial live infectious bursal disease (IBD) vaccines on antibody (Ab) decay and response to a very virulent IBD virus (vvIBDV) and Newcastle disease (ND) vaccine La Sota in ISA Brown chicks were assessed. Methods: Seven groups of chickens (A, B, C, D, E, F, and G) comprising 50 chicks each were used for the study. Groups A, B, C, D, and E were vaccinated with Bur-706, MB-Strain, B87-Strain, Bursa-B2K, and HIPRA live IBD vaccines, respectively, at 14 and 28 days of age (doa), and challenged with a vvIBDV at 35 doa. Groups F and G served as positive and negative controls, respectively. At 42 doa, all groups were vaccinated with ND vaccine La Sota. Blood was collected at 1, 7, 14, 21, 28, 35, 42, and 49 doa, and serum was harvested. The serum was analyzed for IBD virus (IBDV) Ab titres using enzyme-linked immunosorbent assay (ELISA) and ND Ab titres using a haemagglutination inhibition (HI) test. Results: Results revealed significantly (p < 0.05) higher ELISA IBDV Ab titres in groups A to E than in F from 21 to 49 doa, with the highest in group D. At 49 doa, there was significantly (p < 0.05) higher HI Ab titre in groups A to E than in F with the highest in group D. In conclusion, the live IBDV vaccines were immunogenic following vaccination. The vaccines decreased the decay of IBDV Ab and mitigated the decreased response to ND vaccine La Sota in the chicks following the vvIBDV challenge, with more effects induced by Bursa-B2K. Conclusion: The live vaccines (Bur-706, MB-Strain, B87-Strain, Bursa-B2K, and HIPRA) were immunogenic following vaccination.

Effects of two supplements on rate of infectious bursal disease virus antibody decay and response to a very virulent strain of the virus in pullet chicks

This study evaluated the effects of two supplements on the rate of infectious bursal disease virus (IBDV) antibody decay and response to a very virulent strain of the virus (vvIBDV) in pullet chicks. Two hundred ISA Brown 1-day-old chicks were divided into four groups (AD), each containing 50 birds. Chicks in group A were given supplement A, and B supplement B, from 1-day-old to 42 days of age, while C (positive control) and D (negative control) were not given any supplement. Groups A, B and C were challenged with vvIBDV at 28-days-old. Blood was collected from each bird, serum was obtained and analysed for antibodies against IBDV. The rate of antibody decay and response to vvIBDV were determined. There was significantly higher (p<0.05) antibody titre in chicks of groups A and B than in C and D at days 28, 35 and 42. The rate of antibody decay was lower in chicks of groups A (-57.7%) and B (-65.4%) than in C (-72.1%) and D (-74.2%) at 28-days-old. The antibody response rate was higher in groups A (+76.4%) and B (+71.1%) at 35-days-old. There was lower antibody decline rate in groups A (-22.4%) and B (-29.0%) compared to C (-38.6%) and D (-51.4%) at 42-days-old. These supplements decreased IBD antibody decay, enhanced antibody response to vvIBDV infection and decreased antibody decline by vvIBDV. Therefore, the use of these supplements in IBD outbreaks to enhance immune responses is recommended.

Selected aspects of infectious bursal disease – the current state of knowledge

Infectious bursal disease (IBD) is a highly infectious and contagious immunosuppressive viral disease of chickens with a worldwide economic significance to the poultry industry. Over fifty years have passed since the first confirmed occurrence of the disease, and the virus has spread all over world and evolved into multiple genetic, antigenic and pathotypic variants, becoming a serious threat to the poultry industry. The primary tool in IBD eradication is the maintenance of strict biosecurity in poultry farms and implementation of vaccination programmes which should take into account the current epidemiological knowledge about the IBDV strains circulating in the field. This review article presents the current state of knowledge about the infectious bursal disease virus (IBDV) with special regard to the molecular biology of the virus, immunological aspects, as well as current and future prevention strategies.

Supplements Administration during Infectious Bursal Disease Virus Infection in Poultry Evaluation of the Effects of Prebiotic Probiotic and Synbiotic on the Haematological Alterations in Commercial Pullets

The administration of supplements during viral infections in poultry is gaining more attention. This study evaluated the effects of supplements (prebiotic, probiotic and synbiotic) administration on haematological parameters of ISA Brown chicks inoculated with a very virulent infectious bursal disease (vvIBDV). Two hundred and fifty one-day-old chicks were assigned into five groups (A, B, C, D and E) of 50 chicks each. Groups A, B and C were administered molasses, Antox® and EN-FLORAX®, respectively daily via drinking water from 1 to 49 days of age (doa) while D and E were not administered any supplement. Groups A, B, C and D were inoculated with a vvIBDV at 28 doa while E was not inoculated. Blood was collected from all groups at 1, 28, 35, 42 and 49 doa, and processed for haematology using standard laboratory procedures. Results revealed significantly (P<0.05) higher packed cell volume (PCV), haemoglobin concentration, total red blood cells and thrombocyte count in groups A, B and C compared to group D at 35, 42 and 49 doa. Total white blood cells, heterophils and lymphocyte counts were significantly (P<0.05) higher in groups A, B and C than in group D at 35, 42 and 49 doa. The PCV between groups A, B, C and D differed significantly (P<0.05). The haematological changes induced by vvIBDV were mitigated by the supplements in this study. Therefore, molasses, Antox® and EN-FLORAX® could be administered to ameliorate haematological alterations due to vvIBDV infection in poultry.

Isolation and molecular characterization of infectious bursal disease virus circulating in western and central India.

Infectious bursal disease (IBD) caused substantial economic loss in central and western India during 2020 and 2021. The study was conducted to characterize IBD virus (IBDV) from field outbreaks. The study was conducted on 360 samples from 42 poultry flocks. The samples were subjected to histopathology and molecular detection, followed by phylogenetic typing of the partial VP2 gene. The mortality ranged from 15.25 to 60.18%. The necropsy showed hemorrhages on thigh muscles, mottled spleen, swelling of kidneys and bursae with hemorrhages, and cheesy exudate. Histopathology revealed extensive necrosis and depletion of follicular lymphoid cells within the cortex and medulla, along with widespread hemorrhages, edema, and cystic cavities in the bursa. The field isolates showed cytopathic effects in the seventh passage. The cytopathic effects included swelling, rounding, granulation of cytoplasm around the nucleus, fragmentation of the infected cells, and detachment. The reverse transcription-polymerase chain reaction amplified 664 bp partial VP2 gene. The phylogenetic analysis identified 19 field isolates as very virulent IBDVs (vvIBDVs) and three as classical strains. The results indicated that different vvIBDV strains are involved in disease outbreaks in central and western India.

Evaluation of Spirulina Platensis Efficacy Against Local Field Vvibdv Challenge in Broiler Chickens

The antiviral and immunostimulant effect of dietary supplementation of Spirulina platensis (SP) against Infectious bursal disease (IBD) was assessed as follows; 126 one-day-old cobb broiler chicks were randomly distributed into six groups (21 birds/group with three replicates, 7 birds each): negative control (non-vaccinated, and non-challenged ; NC), positive control (non-vaccinated, and challenged; PC), vaccinated control (vaccinated, and challenged; VC), Spirulina 0.1% (vaccinated, 0.1% SP-supplemented, and challenged; VSP-0.1), Spirulina 0.3% (vaccinated, 0.3% SP-supplemented, and challenged; VSP-0.3), and Spirulina 0.5% (vaccinated, 0.5% SP-supplemented, and challenged; VSP-0.5). The chicks in NC, PC, and VC groups were not supplemented with SP. All vaccinated groups, regardless SP supplementation, showed significant improvement of body weight gain (19% in 0.3% SP) and FCR during IBDv challenge (10 dpc) (P˂0.05). On the 10th dpc, IBD ELISA titer in SP-supplemented groups were decreased (P>0.05) than that of G3, suggesting an antiviral efficacy of SP. This antiviral activity was evident by the viral RNA load in the cloacal swabs as well. The viral shedding peak was on the 5th day pc which was significantly decreased on G4-6 (P˂0.05) in comparison to G2 and G3. Also, the bursal ratio was improved in SP supplemented groups comparable to G3. Moreover, in unchallenged broilers, the gene expression of INF-γ and IL-18 were upregulated while that of IL-10 was downregulated in spleen of SP-supplemented chicks. Finally, severe histopathological lesions of kidneys, bursa, thymus, and spleen were observed in G2 which moderately minimized in G3 and were more alleviated in SP-supplemented groups. Collectively, SP supplementation improved body weight gain and decreasing viral shedding with antiviral activity. The mechanisms of SP against IBDV challenge may include cell-mediated immunity promoting effect, antiviral activity, and/or anti-inflammatory effect that should be further studied

Infectious Bursal Disease: Distribution, Pathogenesis and Pathology

Infectious Bursal Disease: Distribution, Pathogenesis and Pathology

Infectious Bursal Disease (Gumboro) in Backyard Chicken in Jordan

Infectious Bursal Disease (Gumboro) in Backyard Chicken in Jordan

Detection and Phylogenetic Analysis of Infectious Bursal Disease Virus Based on both Genome Segments A and B Isolated from Backyard Poultry Punjab, Pakistan

Detection and Phylogenetic Analysis of Infectious Bursal Disease Virus Based on both Genome Segments A and B Isolated from Backyard Poultry Punjab, Pakistan

In-Vitro Identification of Infectious Bursal Disease Virus Isolates from Dakahlia Governorate, Egypt through the Period from 2017 to 2018

In-Vitro Identification of Infectious Bursal Disease Virus Isolates from Dakahlia Governorate, Egypt through the Period from 2017 to 2018

Probiotics in Industrial Poultry Farming

In the conditions of industrial production, the problem of growing poultry with increased resistance to various diseases is relevant because the birds are exposed to various stress conditions. Traditionally, disease prevention is carried out through the use of vaccines, chemical pharmaceuticals, and antibiotics. The global use of therapeutic drugs contributes to the emergence of resistant strains of microorganisms and a decrease in the effectiveness of treatment; some of them have an immunosuppressive effect. The article presents the results of research on the effect of the preparation "Lactobacillus plantarum, Enterococcus faecalis, and Propionibacterium freudenreichii ssp." on the immune status, growth rate, and safety of experimental stock in broiler chickens. Studies were carried out on 150 one-day-old Ross-308 broiler chicks that were divided into three groups of 50 birds. The control Group (G3) was fed a standard ration based on the phases of growth, while the experimental Groups (G1 and G2) were supplemented with probiotics at different doses in the feed. The experiment was designed to last for 41 days. In the 3rd week, the average live weights of G1 and G2 broiler chickens exceeded those of G3 by 5.5 and 4.1%, respectively. In the 6th week, G1 and G2 broiler chicks had average live weights that exceeded those of G3 by 7.7 and 7.4%, respectively. The survival rates of the flocks in G1 and G2 were 4 and 2% higher, respectively than in G3. The average titers for Newcastle Disease and infectious bronchitis viruses in G1 were 314.9 and 53.5% higher, respectively than in G3, while in G2 they were 3.7 and 21.8% lower, respectively. For infectious bursal disease, G1 and G2 exceeded the control group by 74.2 and 6.4%, respectively. The meat yield of G1 and G2 was higher at 17.2 and 9.1%, respectively, compared to G3. Probiotics have shown many beneficial properties, including the ability to improve immunity, gut structure, and gut barrier function in broilers. These factors can improve digestion and absorption, ultimately increasing the quality and safety of products.

Pathological and molecular studies of acute infectious bursal dis-ease in commercial chicken in Andhra Pradesh

Pathological and molecular studies of acute infectious bursal dis-ease in commercial chicken in Andhra Pradesh

Comparative use efficiency of the same type feed additives in the diet of replacement stock and laying hens of the parent herd

The use of two similar feed additives Sorbitox and Probitox in the diet of replacement stock and subsequently in the diet of laying hens, at a dose of 0.50 kg/t of feed allowed to increase the poultry survival rate at 18 weeks of age by 1.4% with the addition of Sorbitox and 6.4% - with Probitox, the group uniformity by 5.3 and 7.3%, respectively, in comparison with the control group. At the same time, the culling of birds in the experimental groups decreased due to endoenteritis and necrotic enteritidis, and the antibody titer to Gumboro disease increased in the blood. During the productive period of laying hens, the difference in the antibody titer was significantly higher, as was the livestock survival rate. The tested feed additives contributed to a better development of ovogenesis organs. As a result, the egg productivity of chickens with Sorbitox was higher than the control group by 6.5%, with Probitox – by 11.6%. The study of the egg incubation qualities showed that the young stock hatching rate from an average egg size in the group with Sorbitox was 6.9% higher than the control group, with Probitox – by 11.0%, and the hatchability of eggs was 1.1 and 1.6% higher than in the average one. In laying hens at the beginning and at the end of egg laying, the number of infertile small eggs decreased in the group with Sorbitox by 0.60%, with Probitox - by 1.0%, large eggs – by 1.23 and 2.45%, respectively. The chicken hatching rate from small and large eggs in poultry of the experimental groups exceeded the control by 2.9-5.9% at the beginning of egg laying, by 10.0-14.8% at its completion at the age of 56 weeks. The addition of Sorbitox in the diet of replacement stock allowed to reduce feed costs for growing one head of service pullet by 6.9%, with Probitox – by 12.6%, to increase the production profitability by 5.5 and 7.8%, and in laying hens of experimental groups, feed costs decreased by 4.4 and 10.0%, profitability increased by 2.0 and 5.3%, respectively.

Outbreak and management of Marek's disease in 16 weeks old pullets in Nigeria: a case report

Marek's disease (MD) remains a major concern to chicken farmers, especially because of its adverse effect on birds' growth, livability, and egg production. Veterinarians often consider the prognosis poor, especially when tumors are seen in organs like the liver, spleen, and lungs. This is a report of an outbreak of acute MD in commercial chickens. In the present study, carcasses of 16 weeks old Isa brown pullets were presented at the Veterinary Teaching Hospital, the University of Jos for investigation. They had been vaccinated at the hatchery against Marek's disease at day old. The disease was diagnosed as Marek's disease based on mortality pattern, necropsy findings, histological observations, and polymerase chain reaction analysis. Secondary bacterial infection was caused by Staphylococcus aureus, susceptible to gentamicin. The affected flock was revaccinated using Izovac® HVT Marek's vaccine. As a follow-up, a gentamicin-doxycycline-based oral preparation: Doxygen®, was administered for five consecutive days at 100g/200 litres of drinking water. A significant reduction in mortality was observed within two weeks of the commencement of treatment. Owing to the slow spreading/killing nature of Marek's disease (unlike Gumboro disease), its early detection and management via revaccination and treating secondary bacterial infection can significantly reduce losses.