Molecular and Antigenic Characterization of Pigeon Pox Virus Isolated in 2017

Abstract

Pigeon pox disease is caused by pigeon pox virus (PPV) that classified within Family Poxviridae, subfamily Chordopoxvirinae, genus Avipoxvirus (APV) which has the largest and the most divergent genome among the chordopoxvirus genera with many species like PPV, Fowl pox virus (FPV) and Turkey pox virus (TPV) (Andraw, 2012). Pigeon pox is a slowly spreading disease characterized by the development of discrete proliferative nodular skin lesions (cutaneous form) characterized by nodular lesions on feather free areas of skin such as legs, peak and eyelids with low mortality and/or fibrino-necrotic lesions on the mucous membrane of the upper respiratory tract (diphtheritic form) with high mortality. In both forms, gross lesions consist of small vesicles that progress further to nodules and finally scab formation Khan et al. (2009) and Hemanth et al. (2014). The conventional laboratory diagnosis of FPV is carried out by electron microscope, virus isolation on chorioallantoic membrane (CAM) of embryonated chicken eggs (ECE) and serologic methods as Virus Neutralization test (VNT) on ECE (Islam et al., 2008). PPV has a double stranded DNA genome which contains a central coding region surrounded by two identical inverted terminal repeat regions. The genome size is 288 kbp approximately and encodes 260 open reading frames Weli et al. (2011). The 4b core protein gene (P4b) of APV encoding a protein with a molecular weight of 75.2 kDa, is usually chosen for comparative genetic analysis. On the other hand, amplification of the AP-p4b by PCR has often been used as a molecular tool for the detection of avian poxviruses (Manarolla et al., 2010). Based on the phylogenetic analysis of (P4b), APV are divided into three clades; clade A (FPV), clade B (Canary Pox virus), and clade C (Psittacine pox virus) (Offerman et al., 2014).

Efficacy of Aerosol Vaccination of Adjuvantd Pigeon Pox Vaccine in Pigeon

“…Through the present study an innovation of new vaccination route for PPV via aerosol was performed and evaluated through using of adjuvanted Gel 01 PPV aerosol vaccine in comparison to the traditional feather follicle vaccination route in pigeon regarding to that one of most important route for PPV infection is via respiratory inhalation mode (OIE, 2018) in order to establishment an effective rapid and less overwrought method for vaccination of large pigeon flock farm and a safe vaccination way without post vaccinal reaction in oriental viable high price racing pigeon. Tissue culture propagated pigeon pox vaccine on Vero cell line with virus titer of10 5.5 TCID 50 / ml was used in this study for aerosol vaccination (Aboul Soud et al, 2018) and(Kaffay et al, 2018), In order to determine the effective field dose 3 susceptible pigeon groups (group 2. 3.and 4) received different field doses of PPV via aerosol without adjuvant (10 2.5 TCID 50 , 10 3.5 TCID 50 and 10 4.5 TCID 50 / field dose) followed by antibody detection by (VNT and indirect ELISA) and challenging with virulent PPV at 21 post vaccination the result represented in Table (2 Advances in Animal and Veterinary Sciences 1.5, SP 1.1 and protection percent of 75% while group 4 received higher field dose showing same protection percent of 80% with non-significant increased NI 2.0 and SP 1.3 similar results obtained by Nagy et al (1990) when they determine the field dose of fowl pox vaccine (FPV) to be used via spray while it was 10 6 TCID 50 / ml for 100 bird.…”