Histopathological and immunohistochemical diagnosis of infectious bursal disease in poultry birds

Abstract

Aim:The aim of the present study was to diagnose infectious bursal disease (IBD) using gross, histopathological, and immunopathological approaches and to compare efficacy of immunohistochemical techniques with conventional diagnostic techniques. Materials and Methods: A total of 33 samples were collected from the six different poultry farms from Ludhiana and the nearby districts. Upon gross analysis of the necropsied birds, the relevant tissue samples such as bursa, kidney, junction of proventriculus and gizzard, heart, and muscles were then processed for histopathological and immunohistochemical studies. Results: Varied macroscopic changes were noted in bursa, characterized as swollen, hemorrhages to atrophy in size. Nonetheless, hemorrhages over thigh muscles were rarely seen. Histologically, the bursa showed prominent fibrotic and atrophic changes. Rarefaction of bursal follicles with intermittent infiltration of lympho-mononuclear cells with chronic cystic changes was additional changes, considered to be paramount for IBD. Expression and localization of IBD specific viral antigens were noticed mainly intracellular to the rarefied areas of bursal follicle section(s), in conjunction to inner lining of the cystic cavities of affected follicles. In addition, the junction of proventriculus and gizzard, the heart muscle, respiratory ciliated epithelium, and proventriculus also revealed positive expression to IBD virus (IBDV) antigen. Advanced immunopathological techniques, i.e., immunofluorescence further testified the evidence of antigen as positive green signal within affected follicles. Further consideration to the reliability of various techniques employed, positive correlation (r=0.64623) was emerged out with conventional pathological scoring. Conclusion: It is concluded that the bursa acts as an organ of choice for demonstrating IBDV antigen for specific diagnosis of disease using immunohistochemistry (IHC), and IHC staining is a precise, specific, rapid, and reliable method to demonstrate the IBDV antigen in the altered tissues due to IBDV infection.

Outbreaks of Virulent Infectious Bursal Disease in Flocks of Battery Cage Brooding System of Commercial Chickens

“…The purpose of this investigation was to determine whether polidine or V-ox at 1 mL/L could significantly reduce typical IBD lesions in chicks infected with IBDV. However, the clinical manifestations and gross lesions observed in this study are similar to those reported previously [ 12 , 24 – 32 ] that chickens infected with IBDV exhibit anorexia, prostration, and white diarrhoea while grossly the BFs appear yellowish, hemorrhagic, and turgid with prominent striations, oedema, and caseous material found and varying degrees of hemorrhages in the thigh and breast muscles and at the junction between gizzard and proventriculus. The microscopic lesions seen in this study are similar to those reported [ 3 , 12 , 25 , 27 , 28 , 32 – 38 ] that found that bursae from IBDV exposed birds showed lymphoid depletion in the bursal follicles, interfollicular oedema, cellular debris in the medullary areas with necrosis, and/or eosinophilic cystic cavitations.…”

Gross, Histopathological, Histoenzymatic and Histochemical Studies on Infectious Bursal Disease in Broiler Chickens

“…The bursa was enlarged in all the groups, but however, if we compare among different groups, it was haemorrhagic with dark red discolouration in severely affected birds (probably infected with highly virulent strain) and in some group's bursa was found to be enlarged, filled with catarrhal exudate but not haemorrhagic. Singh et al (2015) and Morla et al (2016) reported similar changes in the birds affected with IBD. Now on comparing groups on the basis of different age groups, both morbidity and mortality was mostly observed in birds of 21-30 day age group.…”

“…In highly immune suppressed birds, this virus induces apoptosis in bursa of Fabricius, thereby resulting in depletion of B-cells (Withers et al, 2005). Depending on the bird age, two forms of this disease are seen in birds as acute and subclinical forms (immunosuppressive forms) (Singh et al, 2015). This disease is among the frequently observed lymphocytolytic diseases resulting in immunosuppression of birds (Zahid et al, 2016).…”

Chicken endothelial cells are highly responsive to viral innate immune stimuli and are susceptible to infections with various avian pathogens

“…By contrast, these cells were not permissive to a very virulent serotype 1 IBDV, which also does not replicate in chicken embryo fibroblasts. However, very virulent IBDV strains are known to induce oedema and haemorrhagic lesions in the bursa of infected chickens that are accompanied by a systemic coagulopathy syndrome involving ecchymotic haemorrhages in the muscle and mucosa of the proventriculus (Singh et al, 2015). Because very virulent IBDV are pable to efficiently infect macrophages, in addition to bursa B lymphocytes, one might speculate that an excessive innate immune response of infected macrophages could activate EC locally and/or throughout the body through pro-inflammatory cytokine the production, ultimately leading to perturbation of the coagulation pathway.…”