Lumpy skin disease in cattle in central Ethiopia: outbreak investigation and isolation and molecular detection of the virus

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.

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Lumpy skin disease (LSD): Pathomorphological features and molecular detection in dairy cattle of west coastal India

10.22541/au.163326468.83864514/v1 ◽

2021 ◽

Author(s):

Shivasharanappa Nayakvadi ◽

Samruddhi Prasad Joshi ◽

Susitha Rajkumar ◽

ChethanKumar HB ◽

Jagruti Bathini ◽

...

Keyword(s):

Skin Disease ◽

Molecular Detection ◽

Granulomatous Inflammation ◽

Cattle Population ◽

Vacuolar Degeneration ◽

Lumpy Skin Disease ◽

Blood Samples ◽

P32 Gene ◽

Pcr Targeting ◽

Rpo30 Gene

Lumpy skin disease (LSD) is an emerging pox viral disease affecting cattle population worldwide. In India, the first outbreak of LSD is reported during August 2019 in Odisha state, which then followed by outbreaks in crossbred and indigenous cattle population of other states. Present investigation designed to study the prevalence, pathomorphological changes and molecular detection of LSD virus in naturally infected cattle. The overall morbidity of LSD was 4.48% among 30 dairy farms. Skin nodular biopsy, whole blood and serum samples (n= 66) were collected for the diagnosis of LSD by histopathology, PCR and sequencing. The envelope protein gene (P32), Fusion protein (F) and DNA dependent RNA polymerase 30 kDa subunit (RPO30) genes were targeted for PCR testing. Out of 66, 46 cattle showed generalized skin nodules and papules of various sizes (0.5 - 6.5cm) on the skin particularly at neck, face, nose, tail, perineum and udder. Microscopic examination of the skin nodule biopsy tissue revealed presence of diffuse granulomatous inflammation, hyperkeratosis, focal to diffuse vasculitis and lymphangitis, vacuolar degeneration, spongiosis and acanthosis. The inflammatory cells typically comprised of macrophages, lymphocytes, neutrophils and eosinophils along with diffuse necrosis in dermis in chronic cases. The eosinophilic intracytoplasmic viral inclusions in keratinocytes and epithelial cells were detected in few cases. Gel-PCR assay detected P32 gene in 83%, F gene in 72% and RPO30 gene in 77% of skin biopsy samples. Three blood samples were also found positive for P32 gene by PCR. Whereas TaqMan™ probe Real Time PCR targeting EEV glycoprotein gene (LSDV126) detected LSDV in 94% of biopsy samples and three blood samples which indicated its higher sensitive for the diagnosis of LSDV. Phylogenetic analysis of RPO30 gene sequence showed that the isolates from this study were grouped in same cluster with LSDV isolates of Bangladesh, Kenya and other Indian isolates detected during 2019-20.

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Lumpy Skin Disease (LSD): Pathomorphological Features and Molecular Detection in Dairy Cattle of West Coastal India

10.21203/rs.3.rs-1117731/v1 ◽

2021 ◽

Author(s):

Shivasharanappa Nayakvadi ◽

Samruddhi Prasad Joshi ◽

Susitha Rajkumar ◽

Chethan Kumar H. B. ◽

Jagruti Bathini ◽

...

Keyword(s):

Skin Disease ◽

Molecular Detection ◽

Granulomatous Inflammation ◽

Cattle Population ◽

Vacuolar Degeneration ◽

Lumpy Skin Disease ◽

Blood Samples ◽

P32 Gene ◽

Pcr Targeting ◽

Rpo30 Gene

Abstract Lumpy skin disease (LSD) is an emerging pox viral disease affecting cattle population worldwide. In India, the first outbreak of LSD is reported during August 2019 in Odisha state, which then followed by outbreaks in crossbred and indigenous cattle population of other states. Present investigation designed to study the prevalence, pathomorphological changes and molecular detection of LSD virus in naturally infected cattle. The overall morbidity of LSD was 4.48% among 30 dairy farms. Skin nodular biopsy, whole blood and serum samples (n= 66) were collected for the diagnosis of LSD by histopathology, PCR and sequencing. The envelope protein gene (P32), Fusion protein (F) and DNA dependent RNA polymerase 30 kDa subunit (RPO30) genes were targeted for PCR testing. Out of 66, 46 cattle showed generalized skin nodules and papules of various sizes (0.5 - 6.5cm) on the skin particularly at neck, face, nose, tail, perineum and udder. Microscopic examination of the skin nodule biopsy tissue revealed presence of diffuse granulomatous inflammation, hyperkeratosis, focal to diffuse vasculitis and lymphangitis, vacuolar degeneration, spongiosis and acanthosis. The inflammatory cells typically comprised of macrophages, lymphocytes, neutrophils and eosinophils along with diffuse necrosis in dermis in chronic cases. The eosinophilic intracytoplasmic viral inclusions in keratinocytes and epithelial cells were detected in few cases. Gel-PCR assay detected P32 gene in 83%, F gene in 72% and RPO30 gene in 77% of skin biopsy samples. Three blood samples were also found positive for P32 gene by PCR. Whereas TaqMan™ probe Real Time PCR targeting EEV glycoprotein gene (LSDV126) detected LSDV in 94% of biopsy samples and three blood samples which indicated its higher sensitive for the diagnosis of LSDV. Phylogenetic analysis of RPO30 gene sequence showed that the isolates from this study were grouped in same cluster with LSDV isolates of Bangladesh, Kenya and other Indian isolates detected during 2019-20.

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