Diagnosis of naturally occurring lumpy skin disease virus infection in cattle using virological, molecular, and immunohistopathological assays

Abstract

Background and Aim: Lumpy skin disease (LSD) is a contagious viral disease that has great economic losses among Egyptian breeding flocks. The present study was designed to compare the results of different diagnostic approaches used for the diagnosis of LSD virus (LSDV). Materials and Methods: A total of 73 skin nodule samples were collected from suspected infected cattle with LSDV from some Egyptian governorates during 2019 and 2020. Trials for virus isolation (VI) and identification on embryonated chicken eggs (ECEs) were conducted. Molecular detection, histopathological, and immunohistochemical examination were also conducted. Results: The virus was isolated into ECEs, and 58 samples of 73 were positive and gave a characteristic pock lesion on the chorioallantoic membrane. Twenty-two representative nodular skin specimens of the 58 positive samples were selected to be used for molecular, histopathological, and immunohistochemistry (IHC) diagnosis. Conventional polymerase chain reaction succeeded in detecting LSDV DNA in all tested 22 skin nodule samples. Histological examination of skins of different cases revealed various alterations depending on the stage of infection. IHC was used as a confirmatory test for detecting LSDV antigen in the tissues of the skin nodules of infected cattle using specific anti-LSDV antibodies. Lumpy skin viral antigen was detected within the cytoplasm of the epidermal basal cells layer and prickle cell and within the cytoplasm of the hair follicles' epithelial outer and inner roots. Conclusion: This study confirmed the prevalence of LSDV infection in different Egyptian governorates during 2019 and 2020. In addition, histopathology and IHC could be potential methods to confirm Lumpy skin disease infection besidesVI and molecular detection.

Rapid Spread and Genetic Characterisation of a Recently Emerged Recombinant Lumpy Skin Disease Virus in Thailand

“…Concurrently, a total of 841 blood samples, 324 sera, 210 skin nodules, 18 organs, 8 milk samples, and 5 nasal swabs were collected from animals suspected of LSD. One LSDV-infected skin nodule in good condition with complete animal history was selected for histopathological [ 25 ] and IHC studies [ 26 , 27 ]. The clarified fluids from nodular skin tissue homogenates, blood, and milk were frozen at −80 °C for real-time PCR and/or virus isolation.…”

Investigation of the “Antigen Hook Effect” in Lateral Flow Sandwich Immunoassay: The Case of Lumpy Skin Disease Virus Detection

“…Molecular methods, including conventional or real-time polymerase chain reaction and loop-mediated isothermal amplification, are the most sensitive methods for detecting LSDV [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. As far as immunodiagnostics is concerned, serological assays are available to indirectly diagnose LSDV by detecting the immune response to the virus in the blood of infected animals, while assays aimed at detecting viral antigens have not been reported yet, with the exception of the immunohistochemical method for detecting the LSDV antigens in skin nodules of infected cattle [ 20 ]. However, there is a lack of simpler virological tests, such as ELISA, for antigen detection or rapid tests enabling the point-of-need diagnosis of LSD, which would be particularly useful in endemic countries.…”

Understanding the research advances on lumpy skin disease: A comprehensive literature review of experimental evidence

“…The pathological sections made from the skin lesions can be diagnosed by immunohistochemical (IHC) methods, and the distribution of pathogenic antigens can be detected by specific anti-LSDV antibodies. Changes in the dermis and epidermis of the skin after infection with the virus can be observed under the microscope, including watery degeneration, granulomatous reaction, dystrophic calcification of the dermis, and the formation of inflammatory cells ( El-Neweshy et al, 2013 ; Sanz-Bernardo et al, 2020 ; Amin et al, 2021 ). Ali et al observed inclusion bodies in the cytoplasm of bovine skin capsule through histopathological examination, and confirmed that these inclusion bodies were characteristic pathological lesions related to LSD.…”