Molecular characterization and identification of African Swine Fever virus isolates from emerging cases of infection in Central Luzon, Philippines

A study that evaluated the molecular characteristics to confirm the identity of the African Swine Fever (ASF) pathogen from emerging cases of infection in Central Luzon, Philippines was initiated. The study involved the collection of 125 blood samples from pigs during the four-month duration of the study when clinical signs of ASF was prevalent in the four out of seven provinces of Central Luzon, Philippines. This work included the amplification of the p72 gene in DNA samples through PCR and confirmation of the identity of the ASF pathogen through DNA sequencing. The DNA sequences of the p72 gene of the ASF pathogen are made up of 412 nucleotides and used as a basis in identifying the Philippine ASF pathogens as ASF virus PH/CL 4/2022, ASF virus PH/CL 3/2022, ASF virus PH/CL 2/2022 and ASF virus PH/CL 1/2022. Philippines ASF virus isolates showed 100% sequence similarity with sequences reported from Malaysia ASF isolate MVZT218/2021, Vietnam ASF isolate D/ASFV/VN/DN-VC/2019, and India ASF isolate ASF/MZ/IND/3 based on BLASTN homology search in the NCBI database. The results of the study revealed close phylogenetic relationships among ASF isolates from Vietnam, Malaysia, India and the Philippines.