Search Results (7)

Despite the seriousness of the disease carried by ticks, little is known about the Bourbon virus. Only three US states have recorded human cases of Bourbon virus (BRBV) infection; in all cases, a tick bite was connected with the onset of the illness. The Bourbon virus (BRBV) belongs to the Orthomyxoviridae family and Thogotovirus genus, originating in the states of the US, i.e., Kansas, Oklahoma and Missouri. The growing rates of BRBV infections in various parts of the US highlight the necessity for a thorough analysis of the virus’s transmission mechanisms, vector types and reservoir hosts. Currently, there are no vaccines or efficient antiviral therapies to stop these infections. It is imperative to produce a vaccination that is both affordable and thermodynamically stable to reduce the likelihood of future pandemics. Various computational techniques and reverse vaccinology methodologies were employed to identify specific B- and T-cell epitopes. After thorough examination, the linker proteins connected the B- and T-cell epitopes, resulting in this painstakingly constructed vaccine candidate. Furthermore, 3D modeling directed the vaccine construct toward molecular docking to determine its binding affinity and interaction with TLR-4. Human beta-defensin was used as an adjuvant and linked to the N-terminus to boost immunogenicity. Furthermore, the C-IMMSIM simulation resulted in high immunogenic activities, with activation of high interferon, interleukins and immunoglobulin. The results of the in silico cloning process for E. coli indicated that the vaccine construct will try its utmost to express itself in the host, with a codon adaptation CAI value of 0.94. A net binding free energy of −677.7 kcal/mol obtained during docking showed that the vaccine has a high binding affinity for immunological receptors. Further validation was achieved via molecular dynamic simulations, inferring the confirmational changes during certain time intervals, but the vaccine remained intact to the binding site for a 100 ns interval. The thermostability determined using an RMSF score predicted certain changes in the mechanistic insights of the loop region with carbon alpha deviations, but no major changes were observed during the simulations. Thus, the results obtained highlight a major concern for researchers to further validate the vaccine’s efficacy using in vitro and in vivo approaches. Full article

Emerging tick-borne viruses such as Powassan virus (POWV), Bourbon virus (BRBV), and Heartland virus (HRTV), whilst rare, can cause severe health problems in humans. While limited clinical cases have been reported thus far in Virginia, the presence of tick-borne viruses poses a serious health threat, and the extent of their prevalence in Virginia is unknown. Here, we sought evidence of POWV, BRBV, and HRTV exposure in Virginia via a serological assessment of wildlife and livestock. Wildlife in Virginia were found to be seropositive against POWV (18%), BRBV (8%), and HRTV (5%), with western and northern regions of the state having a higher prevalence. Multiple wildlife species were shown to have been exposed to each virus examined. To a lesser extent, cattle also showed exposure to tick-borne viruses, with seroprevalences of 1%, 1.2%, and 8% detected in cattle against POWV, BRBV, and HRTV, respectively. Cross-reactivity against other known circulating mosquito-borne flaviviruses was ruled out. In conclusion, there is widespread exposure to tick-borne viruses in western and northern Virginia, with exposure to a diverse range of animal populations. Our study provides the first confirmation that HRTV is circulating in the Commonwealth. These findings strengthen the existing evidence of emerging tick-borne viruses in Virginia and highlight the need for public health vigilance to avoid tick bites. Full article

Bourbon virus (BRBV, family Orthomyxoviridae) is a tickborne virus recently detected in the United States (US). BRBV was first identified from a fatal human case in 2014 in Bourbon County, Kansas. Enhanced surveillance in Kansas and Missouri implicated Amblyomma americanum as the primary vector for BRBV. Historically, BRBV was only detected in the lower midwestern US, but since 2020 it has been reported in North Carolina, Virginia, New Jersey, and New York State (NYS). This study aimed to elucidate genetic and phenotypic characteristics of BRBV strains from NYS through whole genome sequencing and the assessment of replication kinetics in mammalian cultures and A. americanum nymphs. Sequence analysis revealed the existence of two divergent BRBV clades circulating in NYS. BRBV NY21-2143 is closely related to the midwestern BRBV strains but has unique substitutions in the glycoprotein. Two other NYS BRBV strains, BRBV NY21-1814 and BRBV NY21-2666, form a distinct clade unique from previously sequenced BRBV strains. Phenotypic diversification was also detected in NYS BRBV strains compared to each other and midwestern BRBV strains, with BRBV NY21-2143 displaying attenuation in rodent-derived cell culture and a fitness advantage in experimentally infected A. americanum. These data suggest genetic and phenotypic diversification of emergent BRBV strains circulating in NYS that could contribute to increased spread of BRBV in the northeastern US. Full article

As demonstrated by the 2015 Zika virus outbreak in the Americas, emerging and re-emerging arboviruses are public health threats that warrant research investment for the development of effective prophylactics and therapeutics. Many arboviral diseases are underreported, neglected, or of low prevalence, yet they all have the potential to cause outbreaks of local and international concern. Here, we show the production of virus-like particles (VLPs) using a rapid and efficient recombinant vaccinia virus (VACV) expression system for five tick- and mosquito-borne arboviruses: Powassan virus (POWV), Heartland virus (HRTV), severe fever with thrombocytopenia syndrome virus (SFTSV), Bourbon virus (BRBV) and Mayaro virus (MAYV). We detected the expression of arbovirus genes of interest by Western blot and observed the expression of VLPs that resemble native virions under transmission electron microscopy. We were also able to improve the secretion of POWV VLPs by modifying the signal sequence within the capsid gene. This study describes the use of a rapid VACV platform for the production and purification of arbovirus VLPs that can be used as subunit or vectored vaccines, and provides insights into the selection of arbovirus genes for VLP formation and genetic modifications to improve VLP secretion and yield. Full article

Haemaphysalis longicornis (Neumann, 1901) (Acari: Ixodidae), the Asian longhorned tick, is an invasive tick species present in the USA since at least 2017 and has been detected in one-third of Virginia counties. While this species is associated with the transmission of multiple pathogens in its native geographical range of eastern Asia, little is known about its ability to acquire and transmit pathogens in the USA, specifically those that are transmissible to humans, although from an animal health perspective, it has already been shown to vector Theileria orientalis Ikeda strains. Emerging tick-borne viruses such as Bourbon virus (genus: Thogotovirus) are of concern, as these newly discovered pathogenic agents have caused fatal clinical cases, and little is known about their distribution or enzootic maintenance. This study examined H. longicornis collected within Virginia (from ten counties) for Bourbon and Heartland viruses using PCR methods. All ticks tested negative for Heartland virus via qRT-PCR (S segment target). Bourbon-virus-positive samples were confirmed on two different gene targets and with Sanger sequencing of the PB2 (segment 1) gene. Bourbon virus RNA was detected in one nymphal stage H. longicornis from Patrick County, one nymph from Staunton City, and one larval pool and one adult female tick from Wythe County, Virginia. An additional 100 Amblyomma americanum (Linnaeus 1758; lone star tick) collected at the same Patrick County site revealed one positive nymphal pool, suggesting that Bourbon virus may have spilled over from the native vector, potentially by co-feeding on a shared Bourbon-virus-infected vertebrate host. Blood tested from local harvested deer revealed a 11.1% antibody seroprevalence against Bourbon virus, exposure which further corroborates that this tick-borne virus is circulating in the southwest Virginia region. Through these results, it can be concluded that H. longicornis can carry Bourbon virus and that pathogen spillover may occur from native to invasive tick species. Full article

Tick-borne infectious diseases can affect many tissues and organs including bone, one of the most multifunctional structures in the human body. There is a scarcity of data regarding the impact of tick-borne pathogens on bone. The aim of this review was to survey existing research literature on this topic. The search was performed using PubMed and Google Scholar search engines. From our search, we were able to find evidence of eight tick-borne diseases (Anaplasmosis, Ehrlichiosis, Babesiosis, Lyme disease, Bourbon virus disease, Colorado tick fever disease, Tick-borne encephalitis, and Crimean–Congo hemorrhagic fever) affecting the bone. Pathological bone effects most commonly associated with tick-borne infections were disruption of bone marrow function and bone loss. Most research to date on the effects of tick-borne pathogen infections on bone has been quite preliminary. Further investigation of this topic is warranted. Full article

Tick-borne viral diseases continue to emerge in the United States, as clearly evident from the increase in Powassan encephalitis virus, Heartland virus, and Bourbon virus infections. Tick-borne flaviviruses (TBFVs) are transmitted to the mammalian host along with the infected tick saliva during blood-feeding. Successful tick feeding is facilitated by a complex repertoire of pharmacologically active salivary proteins/factors in tick saliva. These salivary factors create an immunologically privileged micro-environment in the host’s skin that influences virus transmission and pathogenesis. In this review, we will highlight tick determinants of TBFV transmission with a special emphasis on tick–virus–host interactions at the cutaneous interface. Full article