Identification and characterization of a Relish-type NF-κB, DvRelish, in in response to infection.

Ixodid ticks serve as hosts and transmission vectors for several obligate intracellular bacteria, including members of the spotted fever group (SFG) of . Although ticks generate an immune response to bacterial insults, many of the signaling molecules associated with the response and how they may contribute to vector competence for are undefined. In this study, we isolated a full-length transcript from , which encoded a Relish-type NF-κB.

Colorado tick fever virus: a review of historical literature and research emphasis for a modern era.

Colorado tick fever virus is an understudied tick-borne virus of medical importance that is primarily transmitted in the western United States and southwestern Canada. The virus is the type species of the genus Coltivirus (Spinareoviridae) and consists of 12 segments that remain largely uncharacterized. Patterns of viral distribution are driven by the presence of the primary vector, the Rocky Mountain wood tick, Dermacentor andersoni.

Safety study of Rift Valley Fever human vaccine candidate (DDVax) in mosquitoes.

Rift Valley fever virus (RVFV) is a mosquito-borne pathogen with significant human and veterinary health consequences that periodically emerges in epizootics. RVFV causes fetal loss and death in ruminants and in humans can lead to liver and renal disease, delayed-onset encephalitis, retinitis, and in some cases severe haemorrhagic fever. A live attenuated vaccine candidate (DDVax), was developed by the deletion of the virulence factors NSs and NSm from a clinical isolate, ZH501, and has proven safe and immunogenic in rodents, pregnant sheep and non-human primates.

Borrelia miyamotoi strain LB-2001 retains plasmids and infectious phenotype throughout continuous culture passages as evaluated by multiplex PCR.

Borrelia miyamotoi is a tick-borne spirochete of the relapsing fever borrelia group and an emerging pathogen of public health significance. The genomes of relapsing fever borreliae and Lyme disease borreliae consist of multiple linear and circular plasmids in addition to the chromosome. Previous work with B.

Characterization of a Borrelia miyamotoi membrane antigen (BmaA) for serodiagnosis of Borrelia miyamotoi disease.

Borrelia miyamotoi is a tick-borne pathogen that causes Borrelia miyamotoi disease (BMD), an emerging infectious disease of increasing public health significance. B. miyamotoi is transmitted by the same tick vector (Ixodes spp.

Immunoproteomic analysis of Borrelia miyamotoi for the identification of serodiagnostic antigens.

The tick-borne spirochete, Borrelia miyamotoi, is an emerging pathogen of public health significance. Current B. miyamotoi serodiagnostic testing depends on reactivity against GlpQ which is not highly sensitive on acute phase serum samples.

Spotted Fever Group Infection and Transmission Dynamics in .

Tick vectors are capable of transmitting several rickettsial species to vertebrate hosts, resulting in various levels of disease. Studies have demonstrated the transmissibility of both rickettsial pathogens and novel species or strains with unknown pathogenicity to vertebrate hosts during tick blood meal acquisition; however, the quantitative nature of transmission remains unknown. We tested the hypothesis that if infection severity is a function of the rickettsial load delivered during tick transmission, then a more virulent spotted fever group (SFG) species is transmitted at higher levels during tick feeding.

Role of Sca2 and RickA in the Dissemination of Rickettsia parkeri in Amblyomma maculatum.

The Gram-negative obligate intracellular bacterium is an emerging tick-borne human pathogen. Recently, Sca2 and RickA have been implicated in adherence and actin-based motility in vertebrate host cell infection models; however, the rickettsia-derived factors essential to tick infection are unknown. Using mutants lacking functional Sca2 or RickA to compare actin polymerization, replication, and cell-to-cell spread , similar phenotypes in tick and mammalian cells were observed.

Comparative vertical transmission of Rickettsia by Dermacentor variabilis and Amblyomma maculatum.

The geographical overlap of multiple Rickettsia and tick species coincides with the molecular detection of a variety of rickettsial agents in what may be novel tick hosts. However, little is known concerning transmissibility of rickettsial species by various tick hosts. To examine the vertical transmission potential between select tick and rickettsial species, two sympatric species of ticks, Dermacentor variabilis and Amblyomma maculatum, were exposed to five different rickettsial species, including Rickettsia rickettsii, Rickettsia parkeri, Rickettsia montanensis, Rickettsia amblyommatis, or flea-borne Rickettsia felis.

Nonselective Persistence of a Rickettsia conorii Extrachromosomal Plasmid during Mammalian Infection.

Scientific analysis of the genus Rickettsia is undergoing a rapid period of change with the emergence of viable genetic tools. The development of these tools for the mutagenesis of pathogenic bacteria will permit forward genetic analysis of Rickettsia pathogenesis. Despite these advances, uncertainty still remains regarding the use of plasmids to study these bacteria in in vivo mammalian models of infection, namely, the potential for virulence changes associated with the presence of extrachromosomal DNA and nonselective persistence of plasmids in mammalian models of infection.