Abstract

Capri Pox Virus (Ca PV) is the causative agent of important diseases in sheep and goat with severe socio-economic impact. Sheep Poxvirus (SPPV), Goat Poxvirus (GTPV) and Lumpy Skin Disease Virus (LSDV) are three members of the Capripox virus genus of Poxviridae family, which infect sheep, goats, and cattle, respectively. A rapid diagnostic assay for Ca PV by using conventional PCR RNA polymerase gene RP030 and real-time qPCR would be useful for disease surveillance, detection and differentiation of Ca PV in clinical and subclinical samples for management and treatments of outbreaks. The present study aimed to detect and identify Ca PV (SPPV and GTPV) in natural, infected scabs biopsy samples, which were collected from sheep and goats in different governorates in 2017 during outbreaks in Egypt using the conventional PCR RNA polymerase gene RP030 gene based and Real-Time qPCR fluorescent based. We collected eighty scabs from clinically affected animals (54 sheep and 26 goat) that were vaccinated in Chorio-Allantoic-Membranes (CAM) from 10-days-old embryonated-chicken eggs. The positive CAM showed pock lesions, which were observed with a thickening of the membrane after 2-3 passages post samples inoculation, and harvested positive CAMs, which were determined by Agar Gel Precipitation Test (AGPT) , Counter Immune Electrophoresis (CIE), and conventional PCR and real time qPCR were examined for the presences of Ca PVs. DNA extraction from clinical samples and positive CAM with pox lesions using DNA slandered references extraction kits compared to novel modification method (Microwave extraction). The PCR based RPO30 gene and the real-time qPCR showed 15 positive with percentage 27.77% in 54 sheep and 3 positive with percentage 12.5% in 26 goats. Although, AGPT and CIE gave lower result than molecular methods, they gave 11 and 13 positive samples from 54 sheep and in goats were 1 and 2 from 26 scab biopsy samples respectively, however they are useful for early confirmation of positive Ca PVs in low-income countries. PCR based RNA polymerase gene RP030 gene and real-time-PCR considered sensitive, rapid, and reliable methods for differentiating SPPV and GTPV from AGPT and CIE in CAM or in clinical samples without further isolation and propagation in embryonated-chicken eggs. The novel microwave method used to isolate high quality of DNA extracted from infected skin biopsy with SPPV and GPPV with no further purification steps required. It was done in 3 minutes only. The results of the current study confirmed that the suitability of the PCR-based RNA polymerase gene RP030 gene is suitable for differentiating between SPPV and GTPV; in one PCR run; without any post-processing steps.