Molecular and histopathological findings on induced pulmonary lesions by bovine viral diarrhea virus



BACKGROUND: The bovine viral diarrhea virus (BVDV) is one of the bovine respiratory system pathogens that represses lungs immunity and raises the pathogenicity of other bacteria and viruses. OBJECTIVES: The aim of the present study was to evaluate the effect of BVDV in lung tissue. METHODS: In this study, 30 bovine lung tissues were used. RESULTS: Histopathologic analysis showed different lesions in lung tissues. RT-PCR test results and histopathologic observations were studied for each sample and compared. Kai Square Test was used to study any possible association between the existence of BVD virus and incidence of four common lesions: 1- Interestitial pneumonia, 2- bronchitis and bronchiolitis, 3- edema, emphysema and atelectasis and 4- bronchopneumonia. If the assumptions of X2 test were not applicable, the Fisher Exact Test was used. The RT-PCR test for BVDV results was positive for 10 lung samples. 5 BVD positive cases were involved with interestitial pneumonia, while 10 BVD negative cases were not affected. Finally, in the studied lung tissues, only the 3 + degree or severe interstitial pneumonia was significantly associated with the existence of BVD virus. CONCLUSIONS: No significant relation was seen regarding other possible lesions, which may have resulted from the probable roles of bacteria or other viruses and toxic factors that were not studied in this project.