Analyse phylogénétique d'isolats du virus marocain de la clavelée basée sur le gène P32

Sheeppox virus (SPPV) is considered a highly contagious disease in sheep by the World Organization for Animal Health (OIE). It is classified with Goatpox virus (GTPV) and Lumpy skin disease virus (LSDV) within the Capripoxvirus (CaPV) genus. SPPV causes significant economic losses in endemic regions like Northern and Central Africa, Asia, India and Middle East. In Morocco, little information about the molecular characterization of SPPV is available, hence the objective of the present study is to assess the genomic relationships between Moroccan viral strains isolated from different geographic regions during several outbreaks, vaccine strains and reference strains retrieved from the NCBI Genbank, by sequencing the P32 gene. All sequences were analyzed using MEGA7 software version 7. Phylogenetic tree constructions for this gene sequences were generated using the Neighbor-Joining method. It clearly appeared that SPPV strains reported in many countries, were branched and clustered with the clade of SPPV and displayed a strong genetic relationship between them with nucleotide and amino acid identities respectively of 99-100 % and 98-100 %. These results led us to conclude that P32 gene appears highly conserved among SPPV and Capripoxvirus. For that, more genetic studies are required in order to control and understand the epidemiological situation of SPPV. Keywords: Sheeppox virus, P32 gene, Phylogenetic analysis, Capripoxvirus, Goatpox virus.La clavelée (SP) est une maladie considérée hautement contagieuse par l’Organisation Mondiale de la santé Animale (OIE). L’agent causal de la maladie (SPPV) appartient au genre des Capripoxvirus contenant ainsi le virus de la variole de chèvre (GTPV) et le virus de la maladie nodulaire cutanée (LSDV). Le SPPV cause des pertes économiques considérables dans les zones endémiques telles que l’Afrique du nord et centrale, l’Asie, l’inde et le moyen orient. Au Maroc, peu d’étude de caractérisation moléculaire du SPPV sont disponibles, d’où l’objectif du présent travail qui vise à évaluer la relation génétique entre les souches virales marocaines isolées à partir de différentes régions du Maroc durant les flambées épizootiques, des souches vaccinales et des souches de références publiées sur Genbank, et ce, par le séquençage du gène P32. Toutes les séquences sont analysées par le logiciel MEGA 7.0, l’arbre phylogénétique est généré par la méthode Neighbour-Joining. Il apparaît clairement que tous les SPPV rapportés dans la plupart des pays sont branchés et groupés dans le clade du SPPV, et ont montré une forte relation génétique entre eux avec une identité d’acides nucléiques et d’acides aminés de 99-100 % et 98-100 % respectivement. Ces résultats nous mènent à conclure que le gène P32 apparaît hautement conservé chez tous les SPPV et les Capripoxvirus. Pour cela, plus d’études génétiques sont nécessaires afin de contrôler et expliquer la situation épidémiologique du SPPV. Mots-clés: Sheeppox virus, gène P32, analyse phylogénétique, Capripoxvirus, Goatpox virus

Current situation, genetic relationship and control measures of infectious bronchitis virus variants circulating in African regions

Infectious bronchitis virus (IBV) is a major viral pathogen of commercial poultry, affecting chickens of all ages and causing major economic losses in poultry industry worldwide. Frequent points of mutations and recombination events in the S1 gene region, result in the emergence of new IBVs variants circulating in the form of several serotypes/genotypes that can be partially or poorly neutralized by current vaccines. IBV is well studied worldwide, nevertheless in African countries epidemiological and scientific data are poor and not updated. This review aims to give a current overview of IBV situation, to establish evolutionary relationship between the African variants and to list some of the potential measures to control IBV in Africa. Three S1 gene hypervariable regions were studied and compared to the reference genotypes/serotypes that found emerging in African regions. This comparison was based on phylogenetic trees, nucleotide and amino-acid sequence analysis. It clearly appears that IBV variants reported in Africa, display a low genetic relationship between them and with the majority of the reference strains emerging in neighboring countries, except the case of variants from Libya and Egypt that show a high relatedness. Also the Massachusetts serotypes were the most prevalent co-circulating with both serotypes, Italy02 type in Morocco and Qx-like genotype in South part of the African continent. In order to control the IBV variants in African regions, an efficient vaccination strategy program should be implemented