DNA segments of African Swine Fever Virus detected for the first time in hard ticks from sheep and bovines

2019 ◽  
Vol 24 (1) ◽  
pp. 180 ◽  
Author(s):  
Ze Chen ◽  
Xiaofeng Xu ◽  
Yufeng Wang ◽  
Jinlong Bei ◽  
Xiufeng Jin ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Control Measures ◽  
Single Amino Acid ◽  
Small Rna Sequencing ◽  
Hard Ticks ◽  
Prevention And Control Measures ◽  
And Control ◽  
First Time

In this study, we detected African Swine Fever Virus (ASFV) in Dermacentor (Ixodidae) from sheep and bovines using small RNA sequencing. To validate this result, a 235-bp DNA segment was detected in a number of DNA samples from D. silvarum and sheep blood. This 235-bp segment had an identity of 99% to a 235-bp DNA segment of ASFV and contained three single nucleotide mutations (C38T, C76T and A108C). C38T, resulting in a single amino acid mutation G66D, suggests the existence of a new ASFV strain, which is different from all reported ASFV strains in the NCBI GenBank database and the ASFV strain (GenBank: MH713612.1) reported in China in 2018. To further confirm the existence of ASFV in Dermacentor ticks, three DNA segments of ASFV were detected in D. niveus females from bovines and their first generation ticks reared in our lab. These results also proved that transovarian transmission of ASFV occurs in hard ticks. This study revealed for the first time that ASFV has a wider range of hosts (e.g. sheep and bovines) and vectors (e.g. hard ticks), beyond the well-known Suidae family and Argasidae (soft ticks). Our findings pave the way toward further studies on ASFV transmission and the development of prevention and control measures.

scholarly journals DNA segment of African Swine Fever Virus first detected in hard ticks from sheep and bovine

2018 ◽  
Author(s):  
Ze Chen ◽  
Xiaofeng Xu ◽  
Xiaojun Yang ◽  
Weihao Dou ◽  
Xiufeng Jin ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Control Measures ◽  
Single Amino Acid ◽  
Small Rna Sequencing ◽  
Hard Ticks ◽  
Wide Range ◽  
Prevention And Control Measures ◽  
And Control

In this study, we aimed to detect viruses in hard ticks using the small RNA sequencing based method. A 235-bp DNA segment was detected in Dermacentor nuttalli (hard ticks) and D. silvarum (hard ticks) from sheep and bovine, respectively. The detected 235-bp segment had an identity of 99% to a 235-bp DNA segment of African Swine Fever Virus (ASFV) and contained three single nucleotide mutations (C38T, C76T and A108C). C38T, resulting in an single amino acid mutation G66D, suggests the existence of a new ASFV strain, which is different from all reported ASFV strains in NCBI GenBank database. These results also suggest that ASFV could have a wide range of hosts or vectors, beyond the well known Suidae family and soft ticks. Our findings pave the way toward further studies of ASFV transmission and development of prevention and control measures.

scholarly journals First-Time Presence of African Swine Fever Virus Genotype II in Nigeria

2021 ◽  
Vol 10 (26) ◽  
Author(s):  
Adeyinka J. Adedeji ◽  
Pam D. Luka ◽  
Rebecca B. Atai ◽  
Toyin A. Olubade ◽  
Dupe A. Hambolu ◽  
...  
Keyword(s):  
Food Security ◽  
West Africa ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Control Measures ◽  
Virus Genotype ◽  
Partial Sequencing ◽  
First Time ◽  
Genotype Ii

A confirmed African swine fever (ASF) outbreak in Nigeria was further investigated by partial sequencing of B464L and E183L genes of the ASF virus (ASFV). Results revealed the first-time presence of ASFV genotype II in Nigeria and West Africa. This finding has serious implications for control measures and food security.

scholarly journals No evidence of African swine fever virus replication in hard ticks

2014 ◽  
Vol 5 (5) ◽  
pp. 582-589 ◽  
Author(s):  
Helena C. de Carvalho Ferreira ◽  
Sara Tudela Zúquete ◽  
Michiel Wijnveld ◽  
Eefke Weesendorp ◽  
Frans Jongejan ◽  
...  
Keyword(s):  
Virus Replication ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Hard Ticks

scholarly journals Risk Analysis of the Transmission Route for the African Swine Fever Virus in Mainland China

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiang-Hong Hu ◽  
Xin Pei ◽  
Gui-Quan Sun ◽  
Zhen Jin
Keyword(s):  
African Swine Fever Virus ◽  
Mainland China ◽  
African Swine Fever ◽  
Infection Risk ◽  
Fever Virus ◽  
Transmission Model ◽  
Transmission Route ◽  
Pork Products ◽  
Python Language ◽  
And Control

African swine fever first broke out in mainland China in August 2018 and has caused a substantial loss to China’s pig industry. Numerous investigations have confirmed that trades and movements of infected pigs and pork products, feeding pigs with contaminative swills, employees, and vehicles carrying the virus are the main transmission routes of the African swine fever virus (ASFV) in mainland China. However, which transmission route is more risky and what is the specific transmission map are still not clear enough. In this study, we crawl the data related to pig farms and slaughterhouses from Baidu Map by writing the Python language and then construct the pig transport network. Following this, we establish an ASFV transmission model over the network based on probabilistic discrete-time Markov chains. Furthermore, we propose spatiotemporal backward detection and forward transmission algorithms in semi-directed weighted networks. Through the simulation and calculation, the risk of transmission routes is analyzed, and the results reveal that the infection risk for employees and vehicles with the virus is the highest, followed by contaminative swills, and the transportation of pigs and pork products is the lowest; the most likely transmission map is deduced, and it is found that ASFV spreads from northeast China to southwest China and then to west; in addition, the infection risk in each province at different times is assessed, which can provide effective suggestions for the prevention and control of ASFV.

scholarly journals Preliminary Analysis of African Swine Fever Virus Carriage and Transmission by Mosquitoes

2021 ◽  
Author(s):  
Weiyun Qin ◽  
Zhongcheng Gao ◽  
Shenglong Wu ◽  
Wenbin Bao
Keyword(s):  
Large Scale ◽  
Mosquito Control ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Qpcr Analysis ◽  
Pig Farms ◽  
Negative Cycle ◽  
Control Procedures ◽  
And Control

Abstract BackgroundMosquitoes are important insect vectors, but whether they can carry and transmit African swine fever virus (ASFV) in large-scale pig farms in China is unknown. ResultsIn this study, probe qPCR analysis was performed on mosquitoes from five pig farms with ASF virus (ASFV). Analysis of ASFV in 463 mosquitoes yielded negative cycle threshold (CT) value), and detection remained negative after mixing samples from all five pig farms. ConclusionsTherefore, mosquitoes appear unlikely to transmit ASFV, and pose little threat to large-scale pig farms. Thus, farms should continue to follow normal mosquito control procedures when formulating strategies for the prevention and control of ASF.

scholarly journals Efficient inactivation of African swine fever virus by a highly complexed iodine combined with compound organic acids

2022 ◽  
Author(s):  
Mengnan Qi ◽  
Li Pan ◽  
Ying Gao ◽  
Miao Li ◽  
Yanjin Wang ◽  
...  
Keyword(s):  
Organic Acids ◽  
African Swine Fever Virus ◽  
Synergistic Effects ◽  
African Swine Fever ◽  
Fever Virus ◽  
High Morbidity ◽  
Wild Type ◽  
Cleaning And Disinfection ◽  
And Control ◽  
Effective Compound

African swine fever (ASF) is a highly contagious disease with high morbidity and mortality caused by African swine fever virus (ASFV). Cleaning and disinfection remain one of the most effective biosecurity measures to prevent and control the spread of ASFV. In this study, we evaluated the inactivation effects of highly complexed iodine (HPCI) combined with compound organic acids (COAs) against ASFV under different conditions. The results showed that the inactivation rates of the disinfectants on the reporter ASFV increased in dose- and time-dependent manners, the best inactivation effects were obtained when the compatibility ratio of HPCI and COAs was 5:1 at 25°C. Furthermore, there were no significant differences by comparing the efficacy of HPCI combined with COAs (HPCI+COAs) in inactivating wild-type ASFV and the reporter ASFV (P > 0.05). ASFV of 104.0 TCID50/mL was completely inactivated by 0.13% HPCI (0.0065% effective iodine), 0.06% COAs or 0.13% HPCI+COAs (approximately 0.0054% effective iodine), respectively, while 106.0 TCID50/mL ASFV was completely inactivated by 1.00% HPCI (0.05% effective iodine), 0.50% COAs or 1.00% HPCI+COAs (0.042% effective iodine), respectively. Therefore, HPCI+COAs had synergistic effects to inactivate ASFV. This study demonstrated that HPCI+COAs could rapidly and efficiently inactivate ASFV and represent an effective compound disinfectant for the control of ASF.

scholarly journals Peptide OPTX-1 From Ornithodoros papillipes Tick Inhibits the pS273R Protease of African Swine Fever Virus

2021 ◽  
Vol 12 ◽  
Author(s):  
Jingjing Wang ◽  
Mengyao Ji ◽  
Bingqian Yuan ◽  
Anna Luo ◽  
Zhenyuan Jiang ◽  
...  
Keyword(s):  
Structural Information ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Coagulation System ◽  
Hard Tick ◽  
Hard Ticks ◽  
Blood Sucking ◽  
Peptide Toxin ◽  
Underlying Mechanisms

African swine fever virus (ASFV) is a large double-stranded DNA virus and causes high mortality in swine. ASFV can be transmitted by biological vectors, including soft ticks in genus Ornithodoros but not hard ticks. However, the underlying mechanisms evolved in the vectorial capacity of soft ticks are not well-understood. Here, we found that a defensin-like peptide toxin OPTX-1 identified from Ornithodoros papillipes inhibits the enzyme activity of the ASFV pS273R protease with a Ki=0.821±0.526μM and shows inhibitory activity on the replication of ASFV. The analogs of OPTX-1 from hard ticks show more inhibitory efficient on pS273R protease. Considering that ticks are blood-sucking animals, we tested the effects of OPTX-1 and its analogs on the coagulation system. At last, top 3D structures represented surface analyses of the binding sites of pS273R with different inhibitors that were obtained by molecular docking based on known structural information. In summary, our study provides evidence that different inhibitory efficiencies between soft tick-derived OPTX-1 and hard tick-derived defensin-like peptides may determine the vector and reservoir competence of ticks.

scholarly journals Evaluation of Lesions and Viral Antigen Distribution in Domestic Pigs Inoculated Intranasally with African Swine Fever Virus Ken05/Tk1 (Genotype X)

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 768
Author(s):  
Pedro J. Sánchez-Cordón ◽  
Tobias Floyd ◽  
Daniel Hicks ◽  
Helen R. Crooke ◽  
Stephen McCleary ◽  
...  
Keyword(s):  
Viral Antigen ◽  
African Swine Fever Virus ◽  
Clinical Signs ◽  
African Swine Fever ◽  
Virus Genome ◽  
Virus Antigen ◽  
Fever Virus ◽  
Control Measures ◽  
Vascular Lesions ◽  
Domestic Pigs

The understanding of the pathogenic mechanisms and the clinicopathological forms caused by currently circulating African swine fever virus (ASFV) isolates is incomplete. So far, most of the studies have been focused on isolates classified within genotypes I and II, the only genotypes that have circulated outside of Africa. However, less is known about the clinical presentations and lesions induced by isolates belonging to the other twenty-two genotypes. Therefore, the early clinicopathological identification of disease outbreaks caused by isolates belonging to, as yet, not well-characterised ASFV genotypes may be compromised, which might cause a delay in the implementation of control measures to halt the virus spread. To improve the pathological characterisation of disease caused by diverse isolates, we have refined the macroscopic and histopathological evaluation protocols to standardise the scoring of lesions. Domestic pigs were inoculated intranasally with different doses (high, medium and low) of ASFV isolate Ken05/Tk1 (genotype X). To complement previous studies, the distribution and severity of macroscopic and histopathological lesions, along with the amount and distribution of viral antigen in tissues, were characterised by applying the new scoring protocols. The intranasal inoculation of domestic pigs with high doses of the Ken05/Tk1 isolate induced acute forms of ASF in most of the animals. Inoculation with medium doses mainly induced acute forms of disease. A less severe but longer clinical course, typical of subacute forms, characterised by the presence of more widespread and severe haemorrhages and oedema, was observed in one pig inoculated with the medium dose. The severity of vascular lesions (haemorrhages and oedema) induced by high and medium doses was not associated with the amount of virus antigen detected in tissues, therefore these might be attributed to indirect mechanisms not evaluated in the present study. The absence of clinical signs, lesions and detectable levels of virus genome or antigen in blood from the animals inoculated with the lowest dose ruled out the existence of possible asymptomatic carriers or persistently infected pigs, at least for the 21 days period of the study. The results corroborate the moderate virulence of the Ken05/Tk1 isolate, as well as its capacity to induce both the acute and, occasionally, subacute forms of ASF when high and medium doses were administered intranasally.

scholarly journals Research Advances in African Swine Fever Virus (minireview)

2019 ◽  
pp. 8-15
Author(s):  
Jianhe Hu ◽  
Halyna Rebenko ◽  
Jingjing Zhang
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Diagnostic Techniques ◽  
Fever Virus ◽  
Target Cells ◽  
Swine Industry ◽  
Subunit Vaccines ◽  
The World ◽  
Inactivated Vaccines ◽  
And Control

African swine fever remains one of most economically threatened diseases that has been hurting to the swine industry in Ukraine since 2014 and in China since 2018. African swine fever is an acute, highly lethal infectious disease caused by African swine fever virus, which has occurred and spread in many countries around the world, causing a catastrophic blow to the swine industry in the affected countries. ASFV is characterized of large genome, encoding 150-200 proteins, including variety of immunoregulatory proteins, which can resist immunity. African swine fever virus mainly enters pigs through the respiratory and digestive tract. The target cells infected are mainly mononuclear-macrophages, and the receptor is still unclear. Research on the development of diagnostic techniques and tests related to African swine fever are continuing and their proper using is crucial. There are many studies on African swine fever virus vaccines, including inactivated vaccines, attenuated vaccines, subunit vaccines and genetic vaccines. But so far these vaccines have not been able to protect domestic pigs from African swine fever virus infection. The article mainly reviews the researches of ASF virus, epidemiology, pathogenesis, diagnostic techniques and attempts to vaccine`s develop, that provides theoretical basis for the prevention and control of ASF.

scholarly journals African Swine Fever Virus Armenia/07 Virulent Strain Controls Interferon Beta Production through the cGAS-STING Pathway

2019 ◽  
Vol 93 (12) ◽  
Author(s):  
Raquel García-Belmonte ◽  
Daniel Pérez-Núñez ◽  
Marco Pittau ◽  
Juergen A. Richt ◽  
Yolanda Revilla
Keyword(s):  
Wild Boar ◽  
Immune Modulation ◽  
Molecular Mechanisms ◽  
African Swine Fever Virus ◽  
Virulent Strain ◽  
African Swine Fever ◽  
Fever Virus ◽  
Type I ◽  
Sting Pathway ◽  
First Time

ABSTRACT African swine fever virus (ASFV) is a complex, cytoplasmic double-stranded DNA (dsDNA) virus that is currently expanding throughout the world. Currently, circulating virulent genotype II Armenia/07-like viruses cause fatal disease in pigs and wild boar, whereas attenuated strains induce infections with various levels of chronic illness. Sensing cytosolic dsDNA, mainly by the key DNA sensor cyclic GMP-AMP synthase (cGAS), leads to the synthesis of type I interferon and involves signaling through STING, TBK1, and IRF3. After phosphorylation, STING translocates from the endoplasmic reticulum to the Golgi compartment and to the perinuclear region, acting as an indispensable adaptor connecting the cytosolic detection of DNA to the TBK1-IRF3 signaling pathway. We demonstrate here that attenuated NH/P68, but not virulent Armenia/07, activates the cGAS-STING-IRF3 cascade very early during infection, inducing STING phosphorylation and trafficking through a mechanism involving cGAMP. Both TBK1 and IRF3 are subsequently activated and, in response to this, a high level of beta interferon (IFN-β) was produced during NH/P68 infection; in contrast, Armenia/07 infection generated IFN-β levels below those of uninfected cells. Our results show that virulent Armenia/07 ASFV controls the cGAS-STING pathway, but these mechanisms are not at play when porcine macrophages are infected with attenuated NH/P68 ASFV. These findings show for the first time the involvement of the cGAS-STING-IRF3 route in ASFV infection, where IFN-β production or inhibition was found after infection by attenuated or virulent ASFV strains, respectively, thus reinforcing the idea that ASFV virulence versus attenuation may be a phenomenon grounded in ASFV-mediated innate immune modulation where the cGAS-STING pathway might play an important role. IMPORTANCE African swine fever, a devastating disease for domestic pigs and wild boar, is currently spreading in Europe, Russia, and China, becoming a global threat with huge economic and ecological consequences. One interesting aspect of ASFV biology is the molecular mechanism leading to high virulence of some strains compared to more attenuated strains, which produce subclinical infections. In this work, we show that the presently circulating virulent Armenia/07 virus blocks the synthesis of IFN-β, a key mediator between the innate and adaptive immune response. Armenia/07 inhibits the cGAS-STING pathway by impairing STING activation during infection. In contrast, the cGAS-STING pathway is efficiently activated during NH/P68 attenuated strain infection, leading to the production of large amounts of IFN-β. Our results show for the first time the relationship between the cGAS-STING pathway and ASFV virulence, contributing to uncover the molecular mechanisms of ASFV virulence and to the rational development of ASFV vaccines.

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