Quantification of ASFV DNA and RNA in Ornithodoros Soft Ticks.

Molecular biology methods are highly sensitive to detect the genome of pathogens and to study their biology. Polymerase chain reaction (PCR) and reverse transcription followed by a polymerase chain reaction (RT-PCR) permit the detection of the presence and the replication of African swine fever virus in soft ticks. Here, we described our techniques to detect and quantify DNA and RNA of African swine fever virus in soft ticks including a housekeeping gene of soft ticks as internal control.

HDV-Like Viruses.

Hepatitis delta virus (HDV) is a defective human virus that lacks the ability to produce its own envelope proteins and is thus dependent on the presence of a helper virus, which provides its surface proteins to produce infectious particles. Hepatitis B virus (HBV) was so far thought to be the only helper virus described to be associated with HDV. However, recent studies showed that divergent HDV-like viruses could be detected in fishes, birds, amphibians, and invertebrates, without evidence of any HBV-like agent supporting infection.

A fusion peptide in preS1 and the human protein disulfide isomerase ERp57 are involved in hepatitis B virus membrane fusion process.

Cell entry of enveloped viruses relies on the fusion between the viral and plasma or endosomal membranes, through a mechanism that is triggered by a cellular signal. Here we used a combination of computational and experimental approaches to unravel the main determinants of hepatitis B virus (HBV) membrane fusion process. We discovered that ERp57 is a host factor critically involved in triggering HBV fusion and infection.

Differential vector competence of Ornithodoros soft ticks for African swine fever virus: What if it involves more than just crossing organic barriers in ticks?

Background: Several species of soft ticks in genus Ornithodoros are known vectors and reservoirs of African swine fever virus (ASFV). However, the underlying mechanisms of vector competence for ASFV across Ornithodoros species remain to be fully understood. To that end, this study compared ASFV replication and dissemination as well as virus vertical transmission to descendants between Ornithodoros moubata, O.

Evaluation of un-methylated DNA enrichment in sequencing of African swine fever virus complete genome.

African swine fever is a febrile hemorrhagic fever disease that is caused by the African swine fever virus (ASFV) and is lethal for domestic pigs and wild boar. ASFV also infects soft ticks of the genus Ornithodoros, some species of which can act as a vector for ASFV. Whole genome sequencing of ASFV is a challenge because, due to the size difference of the host genome versus the viral genome, the higher proportion of host versus virus DNA fragments renders the virus sequencing poorly efficient.

Coding-Complete Genome Sequence of an African Swine Fever Virus Strain Liv13/33 Isolate from Experimental Transmission between Pigs and Ornithodoros moubata Ticks.

Here, we report the coding-complete genome sequence of African swine fever (ASF) virus strain Liv13/33, isolated from experimentally infected pigs and ticks. The 11 sequences that we obtained harbored no notable differences to each other, and all of them were closely related to the genome sequence of the Mkuzi 1979 strain of genotype I.

Successful Infection of Domestic Pigs by Ingestion of the European Soft Tick That Fed on African Swine Fever Virus Infected Pig.

African swine fever is a highly lethal hemorrhagic fever of , threatening pig production globally. can be infected by different ways like ingestion of contaminated feed, direct contact with infected animals or fomites, and biting by infected soft tick bites. As already described, European soft ticks ( and ) were not able to transmit African swine fever virus by biting pigs although these ticks maintained the infectious virus during several months; therefore, the possibility for pigs to become infected through the ingestion of infected ticks was questioned but not already explored.

No Experimental Evidence of Co-Feeding Transmission of African Swine Fever Virus between Soft Ticks.

soft ticks are the only known vector and reservoir of the African swine fever virus, a major lethal infectious disease of . The co-feeding event for virus transmission and maintenance among soft tick populations has been poorly documented. We infected , a known tick vector in Africa, with an African swine fever virus strain originated in Africa, to test its ability to infect through co-feeding on domestic pigs.

Comparative vector competence of the Afrotropical soft tick Ornithodoros moubata and Palearctic species, O. erraticus and O. verrucosus, for African swine fever virus strains circulating in Eurasia.

African swine fever (ASF) is a lethal hemorrhagic disease in domestic pigs and wild suids caused by African swine fever virus (ASFV), which threatens the swine industry globally. In its native African enzootic foci, ASFV is naturally circulating between soft ticks of the genus Ornithodoros, especially in the O. moubata group, and wild reservoir suids, such as warthogs (Phacochoerus spp.