Experimental Infection of Domestic Pigs with African Swine Fever Virus Isolated in 2019 in Mongolia

Abstract

African swine fever (ASF) is an infectious viral disease caused by African swine fever virus (ASFV), that causes high mortality in domestic swine and wild boar (Sus scrofa). Currently, outbreaks are mitigated through strict quarantine measures and the culling of affected herds, resulting in massive economic losses to the global pork industry. In 2019, an ASFV outbreak was reported in Mongolia, describing a rapidly progressing clinical disease and gross lesions consistent with the acute form of ASF; the virus was identified as a genotype II virus. Due to the limited information on clinical disease and viral dynamics within hosts available from field observations of the Mongolian isolates, we conducted the present study to further evaluate the progression of clinical disease, virulence, and pathology of an ASFV Mongolia/2019 field isolate (ASFV-MNG19), by experimental infection of domestic pigs. Intramuscular inoculation of domestic pigs with ASFV-MNG19 resulted in clinical signs and viremia at 3 days post challenge (DPC). Clinical disease rapidly progressed, resulting in the humane euthanasia of all pigs by 7 DPC. ASFV-MNG19 infected pigs had viremic titers of 108 TCID50/mL by 5 DPC and shed virus in oral secretions late in disease, as determined from oropharyngeal swabs. Whole-genome sequencing confirmed that the ASFV-MNG19 strain used in this study was a genotype II strain highly similar to other regional strains. In conclusion, we demonstrate that ASFV-MNG19 is a virulent genotype II ASFV strain that causes acute ASF in domestic swine.

Characterization ofB646L(p72) gene and the resistance pattern of African swine fever Virus tolerant to indigenous Doom Pig breeds of India

“…The present study also conducted an in-depth analysis of B646L (p72 Overall the results of the present study and a previous study (10)(11)(12) showed high stability and no genetic diversity in the B646L (p72) gene in the ASFV genome. One study conducted B646L (p72) gene in China also shows that ASFV genotype II is predominant among the 24 genotypes (13).…”

Pathogenicity and Pathological Characteristics of African Swine Fever Virus Strains from Pig Farms in South Korea from 2022 to January 2023

“…According to the criteria for the clinical course and pathogenicity of ASFV [ 2 ], the clinical signs, survival period, mortality rate, and pathological lesions observed in animals challenged with the two Korean ASFV isolates corresponded to those of the acute form of illness. This clinical disease progression of both Korean strains is similar to that of the highly virulent p72 genotype II strains, including Georgia 2007/1, Armenia 07, Pig/Heilongjiang/2018, VNUA/HY/Vietnam, and ASFV Mongolia/2019 [ 25 , 26 , 27 , 28 , 29 ]. The results demonstrated that both Korean ASFV strains were highly virulent.…”

Immunization of pigs with replication-incompetent adenovirus-vectored African swine fever virus multi-antigens induced humoral immune responses but no protection following contact challenge

“…Briefly, ASFV DNA was extracted and purified from samples using the automated magnetic bead KingFisher Flex equipment (ThermoFisher, 5400610, MA, USA) that utilizes the Total DNA Extraction Kit (GeneReach, Taiwan) as previously described ( 20 ). Quantitative real-time PCR for the detection of the ASFV gene encoding the p72 antigen (primers: Integrated DNA Technology, IA, USA, and probe: ThermoFisher, MA, USA) was performed in duplicate wells using PerfeCTa ® FastMix ® II (Quanta Biosciences, MA, USA) and following reagent and cycle parameters as previously described on the Stratagene Mx3005p Real-Time PCR Detection System (Agilent, CA, USA) ( 20 , 40 ).…”