Molecular genotyping, histopathological and immunohistochemical studies of bovine papillomatosis

Abstract

Background: Bovine papillomatosis (BP) is considered the most common health problem in large cattle farms.
Aim: This study attempts to confirm clinically suspected BP in cattle by polymerase chain reaction (PCR) assay, histopathology, immunohistochemistry (IHC), and genotyping analysis of local isolates.
Methods: According to morphological appearance and lesion features, a cross sectional study of 54 clinically diagnosed BP cattle was assigned to this current investigation from May to August (2021) in Al-Kut district (Wasit Province, Iraq) private veterinary clinics using purposive sampling technique based on set criteria. The cattle were diagnosed clinically, and the tissues were collected and some fixed in 10% neutral buffered formalin and other stored frozen and examined by histopathological technique, IHC, and PCR assays.
Results: Using PCR assay, all cattle were positive for the BPV L1 gene. According to detect the L1 gene, analysis of the phylogenetic tree showed that local BPV cattle isolates were closely related to the NCBI-BLAST BPV type-1 and type-2 of the Polish equine isolate (KF284133.1) and BPV Brazilian Bostaurus isolate (MH187961.1), respectively. Histological detection showed there were acanthosis, hyperkeratosis, epidermal thickening, severe infiltration of mononuclear cells, massive hemorrhage, dermal fibroplasias, multifocal spongiosis, moderate neovascularization, moderate to severe elongation of the retention ridge towards the dermis, parakeratosis, rings of calcification, and necrosis with nuclear pyknosis of some spinosum cells. Immunohistochemical findings of tumor necrosis factor-alpha, epidermal growth factor receptor and Fascin showed a significant variation in values of immunoreaction in the dermis and epidermis. These results ranged from negative (0) to mild positive (+1) to moderate positive (+2) reactions.
Conclusion: The study provided essential molecular and genotyping data to improve our knowledge by emphasizing the crucial of IHC as an elegant diagnostic method to detect cellular alterations.