Veterinary Research Forum

Abstract The aim of this study was to investigate the presence of bovine herpesvirus type 1 and bovine parainfluenza virus type 3 (PI-3) in cattle lungs exhibiting pneumonia symptoms observed during macroscopic examination. Polymerase chain reaction, double immunohistochemistry, and double immunofluorescence methods were used for viral detection. For this purpose, during the summer-autumn period of 2023, a total of 84 lung samples from cattle aged 1 year and older, exhibiting macroscopic signs of pneumonia, were collected in Kayseri province, Türkiye. Pneumonia lesions were recorded according to the anatomical locations. In virus detection, PI-3 was identified at a rate of 8.33% using double immunohistochemistry/immunofluorescence staining methods, while this rate was found to be 6.72% in polymerase chain reaction. Bovine herpesvirus type 1 was not detected by any of the three methods. In the cattle lungs, 44 lesions (52.38%) were detected in the apical lobe, while seven lesions (8.33%) were detected in the middle lobe, eight lesions (9.52%) in the accessory lobe, and 25 lesions (29.76%) in the basal lobe. The PI-3 immunopositivity was observed in alveolar epithelial cells, as well as mononuclear cells in the interstitial and peri-vascular regions. This study is the first to examine bovine herpesvirus type 1 and PI-3 presence in bovine lungs using three distinct validation techniques (polymerase chain reaction, double immunohistochemistry, and double immunofluorescence).

Abstract Goose parvovirus causes major economic losses in the waterfowl industry due to the high mortality. Therefore, it is essential to establish protection/control objectives in the fight against the disease. The genome of goose parvovirus consists of three structural proteins, including VP1, VP2, and VP3. The VP2 is a candidate antigen in developing vaccines and diagnostic kits. This study aimed to produce the VP2 protein from a local goose parvovirus strain that causes serious infections in geese in Türkiye using the baculovirus expression vector system. To achieve this, the VP2 gene was first amplified by polymerase chain reaction, followed by purification and insertion into the pENTR™/TEV/D-TOPO™ entry vector. Then, the target gene in the pENTR™/TEV/D-TOPO™ vector was transferred to linear N-Term BaculoDirect™ DNA through LR recombination (site-specific recombination between attL and attR sites). The construct was transfected into Spodoptera frugiperda cells. To verify the production of baculoviral virions, a band of approximately 600 bp in length was obtained as a result of polymerase chain reaction amplification using external primer sets for both the VP2 gene and expression vector. The obtained band was purified and sequenced for confirmation. In addition, to confirm the production of the recombinant protein, western blot analysis was conducted utilizing the V5 epitope located at the N-terminus of the expressed protein, resulting in the detection of a ~65.00 kDa band corresponding to the VP2 gene. To detect protein expression in S. frugiperda cells infected with the recombinant baculovirus, immunofluorescence analysis was performed using the same epitope.