ABSTRACT
Lack of availability of commercial antibodies against whole-cell antigen or an antigenic epitope of Avibacterium paragallinarum (Av. paragallinarum) has hindered the development of novel immunoassays for the diagnose infectious coryza (IC). In this study, we raised polyclonal antisera against Av. paragallinarum and evaluated its antigenic-specificity using enzyme linked immunosorbent assay (ELISA). We standardized antigen coating concentration(s), antibody detection limit, and optimal range of dilutions of primary antisera and secondary conjugated antibody. Our results show the development of antigen-specific antibody response in rabbits following repeated antigenic exposure with 0.5% formalinized antigen over a period of four weeks. Further, we showed its possible applicability in detection of pathogens in tissues by immunohistochemistry for confirmatory disease diagnosis and disease pathogenetic study.
ABSTRACT
AIM: Infectious porcine bronchopneumonia, caused by Pasteurella multocida, is a widespread disease of major economic significance. Thus, the aim of the present study was to diagnose swine Pasteurellosis using gross, histopathological, and immunopathological approaches in the swine population of Punjab and to compare the efficacy of immunohistochemical (IHC) techniques with conventional diagnostic techniques. MATERIALS AND METHODS: A total of 71 adult swine lung samples showing gross pneumonic changes were collected along with the associated lymph nodes to carry out the study. The collected samples were then processed for histopathological and IHC studies. RESULTS: Out of the total 71 lung samples, 26 samples were found to be suspected for Pasteurellosis as per the microscopic changes observed, and out of these 26 samples, 16 cases were confirmed to be positive for Pasteurellosis by IHC. Varied macroscopic changes noted in lungs were pneumonic patches with consolidation of many lobes, congestion, and focal hemorrhages. Main lesions associated with lymph nodes were its enlargement and hemorrhages. Histologically, the lung showed fibrinous and suppurative bronchopneumonia, multifocal suppuration, thickening of septa with fibrin combined with cellular infiltration and edema. The higher IHC expression of P. multocida was seen in the bronchial epithelium besides in alveolar and bronchial exudate. Moreover, on comparing the histopathological and IHC scores which were calculated on the basis of characteristic microscopic lesions and number of antigen positive cells, respectively, a significant positive correlation (r=0.4234) was found. CONCLUSION: It was concluded that swine population of Punjab is having P. multocida infection. The gross and histopathological lesions can be helpful in the preliminary diagnosis of Pasteurellosis but needs to be supplemented by other immunodiagnostic tests. Moreover, IHC technique proved to be a specific, reliable, precise, and rapid technique to supplement these conventional methods of diagnosis for Pasteurellosis.
ABSTRACT
Various possible causes of proventriculitis include virus, bacteria, fungus, protozoans, nematodes, biogenic amines and excessive copper sulphate. In the present case, parasites were found in the lumen of the proventriculus, gizzard and duodenum of a poultry bird. Characteristic features of the parasite were studied and confirmed as Ascaridia galli. An ulcerative proventriculitis evident as denuded superficial epithelium, sub-epithelial hemorrhages, infiltration of the inflammatory cells and fibrosis were seen at histopathology. Proventriculitis caused by A. galli has not been reported till date. Here, we report a case of ulcerative proventriculitis in a poultry bird caused by nematode, A. galli.