In vivo and in vitro characterization of a new Oya virus isolate from Culicoides spp. and its seroprevalence in domestic animals in Yunnan, China

Abstract

Biting midges are one of the most common hematophagous insects. They are capable of transmitting a wide range of arboviruses and have a significant impact on public health and veterinary medicine. Herein, from midge samples collected in 2013 in Yunnan, China, one sample induced a cell cytopathic effect (CPE) in BHK-21, MA104, and PK15 cell lines. Next-generation sequencing data, RACE and PCR determined the genome sequence of the sample and designated as an Oya virus (OYAV) isolate SZC50. Phylogenetic analysis of the sample revealed that it was cluster into viruses from species Orthobunyavirus catqueense. The open reading frames of S, M, and L segment of OYAV SZC50 were closest to those of OYAV SC0806. Moreover, 831 serum samples (736 pigs, 45 cattle, and 50 sheep) were gathered from 13 cities in Yunnan Province to detect neutralizing antibody of OYAV SZC50. A significant proportion of OYAV SZC50 antibody (more than 30%) was found in Yunnan pig populations, with the positive rate of OYAV SZC50 antibody in pigs from Malipo reaching 95%. To determine the pathogenicity of OYAV SZC50, we chose three animal models: specific pathogen-free Kunming mice, C57BL/6 mice lacking the interferon α/β receptor, and chicken embryos. At 5, 6, and 7 days post-infection, all adult and suckling C57BL/6 mice, and specific pathogen-free suckling Kunming mice were dead. Our finding was expanding the knowledge about the infection and pathogenic risk of the neglected virus in the Orthobunyavirus.

Evaluating the mosquito vector range for two orthobunyaviruses: Oya virus and Ebinur Lake virus

“…The EBIV (Cu20-XJ) was isolated from field Cx . modestus [ 20 ], and the OYAV (SZC50) was isolated from field biting midge samples [ 18 ].…”

“…Oya virus (strain SZC50), isolated from midges in Yunnan, China [ 18 ], and EBIV (strain Cu20-XJ), isolated from Cx. modestus in Xinjiang, China, were used in this study [ 20 ].…”

“…Ebinur Lake virus, a member of the Bunyamwera serogroup, was initially isolated from the pools of Culex modestus in Xinjiang Province, China, and was later detected in various samples from Russia (mosquitoes, ticks, and wild birds) and Kenya ( Dasymys incomtus and Herpestes ichneumon ) [ 20 , 21 ]. Experimental investigations have demonstrated that these viruses efficiently infect and replicate within various cell lines derived from vertebrates and mosquitoes [ 18 , 22 ]. Furthermore, studies have proven the lethality of OYAV in suckling and C57BL/6 adult mice [ 18 ] and the fatality of EBIV in BALB/c adult mice [ 23 ].…”

“…Experimental investigations have demonstrated that these viruses efficiently infect and replicate within various cell lines derived from vertebrates and mosquitoes [ 18 , 22 ]. Furthermore, studies have proven the lethality of OYAV in suckling and C57BL/6 adult mice [ 18 ] and the fatality of EBIV in BALB/c adult mice [ 23 ]. Despite the lack of confirmed cases of OYAV and EBIV, a serological survey in Malaysia revealed that 93% of pigs within pig farming zones tested positive for OYAV [ 13 ], and the seroprevalence of OYAV in pigs in Yunnan, China, exceeded 30% [ 18 ].…”

“…Furthermore, studies have proven the lethality of OYAV in suckling and C57BL/6 adult mice [ 18 ] and the fatality of EBIV in BALB/c adult mice [ 23 ]. Despite the lack of confirmed cases of OYAV and EBIV, a serological survey in Malaysia revealed that 93% of pigs within pig farming zones tested positive for OYAV [ 13 ], and the seroprevalence of OYAV in pigs in Yunnan, China, exceeded 30% [ 18 ]. Moreover, antibodies against EBIV have previously been detected in residents of Xinjiang, with an IgM-positive rate of 8% and an IgG-positive rate of 12% in the 211 human serum samples [ 22 ].…”