A systematic review of genotypes and serogroups of African swine fever virus

Abstract

African swine fever virus (ASFV) is the causative agent of African swine fever (ASF). The virus causes an acute highly hemorrhagic disease in domestic pigs, with high mortality. Although the overall genome mutation rate of ASFV, a large DNA virus, is relatively low, ASFV exhibits genetic and antigenic diversity. ASFV can be classified into 24 genotypes on the basis of the B646L gene. Cross-protected ASFV strains can be divided into eight serogroups on the basis of antibody-mediated hemadsorption inhibition. Here, we review research progress on ASFV genotyping and serogrouping, and explain how this information assists in the rapid identification of virus origin during ASF outbreaks and will aid in the development of ASF vaccines.

Keywords: African swine fever virus; Genotype; Serogroup.

Fig. 1

Evolutionary relationships of African swine fever virus (ASFV) strains on the basis of p72 (B646L) gene sequences. The phylogenetic tree was inferred using the maximum-likelihood method and Kimura 2-parameter model based on the partial B646L gene nucleotide sequences. Phylogeny was inferred using 1000 bootstrap replications, and the node values show percentage bootstrap support (only values > 80% are shown). The scale bar shows the number of substitutions per site. The sequences of Asia ASFV isolates are indicated using a closed circle (●)

Fig. 2

Phylogenetic comparison of strains on the basis of CD2v protein/gene sequences. A Eighty-eight amino acids of the CD2v protein were analyzed using MEGA5, with four rate classes, and 100 bootstrap replicates, implemented in the maximum-likelihood method. Bootstrap values > 80% are indicated at appropriate nodes. B Ninety-nucleotide sequences of the CD2v protein-encoding gene EP402R were analyzed using MEGA5 software with 1000 bootstrap replicates, implemented in the neighbor-joining method. Bootstrap values > 80% are indicated at appropriate nodes. The serogroup status of ASFV is indicated. Recent Asian isolates are indicated using a closed circle (●)