Medicine and Health Sciences Commons^™

Newer Surveillance Data Extends Our Understanding Of The Niche Of Rickettsia Montanensis (Rickettsiales: Rickettsiaceae) Infection Of The American Dog Tick (Acari: Ixodidae) In The United States, Catherine A. Lippi, Holly D. Gaff, Robyn M. Nadolny, Sadie J. Ryan

Biological Sciences Faculty Publications

Background: Understanding the geographic distribution of Rickettsia montanensis infections in Dermacentor variabilis is important for tick-borne disease management in the United States, as both a tick-borne agent of interest and a potential confounder in surveillance of other rickettsial diseases. Two previous studies modeled niche suitability for D. variabilis with and without R. montanensis, from 2002-2012, indicating that the D. variabilis niche overestimates the infected niche. This study updates these, adding data since 2012.

Methods: Newer surveillance and testing data were used to update Species Distribution Models (SDMs) of D. variabilis, and R. montanensis infected D. variabilis, in …

Tick Ecdysteroid Hormone, Global Microbiota/Rickettsia Signaling In The Ovary Versus Carcass During Vitellogenesis In Part-Fed (Virgin) American Dog Ticks, Dermacentor Variabilis, Loganathan Ponnusamy, Haley Sutton, Robert D. Mitchell Iii, Daniel E. Sonenshine, Charles S. Apperson, Richard Michael Roe

Biological Sciences Faculty Publications

The transovarial transmission of tick-borne bacterial pathogens is an important mechanism for their maintenance in natural populations and transmission, causing disease in humans and animals. The mechanism for this transmission and the possible role of tick hormones facilitating this process have never been studied. Injections of physiological levels of the tick hormone, 20-hydroxyecdysone (20E), into part-fed (virgin) adult females of the American dog tick, Dermacentor variabilis, attached to the host caused a reduction in density of Rickettsia montanensis in the carcass and an increase in the ovaries compared to buffer-injected controls. This injection initiates yolk protein synthesis and uptake …

Multistate Survey Of American Dog Ticks (Dermacentor Variabilis) For Rickettsia Species, Joy A. Hecht, Michelle E.J. Allerdice, Elizabeth A. Dykstra, Laura Mastel, Rebecca J. Eisen, Tammi L. Johnson, Holly D. Gaff, Andrea S. Varela-Stokes, Jerome Goddard, Benedict B. Pagac, Christopher D. Paddock, Sandor E. Karpathy

Biological Sciences Faculty Publications

Dermacentor variabilis, a common human-biting tick found throughout the eastern half and along the west coast of the United States, is a vector of multiple bacterial pathogens. Historically, D. variabilis has been considered a primary vector of Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever. A total of 883 adult D. variabilis, collected between 2012 and 2017 from various locations in 12 states across the United States, were screened for rickettsial DNA. Tick extracts were evaluated using three real-time PCR assays; an R. rickettsii-specific assay, a Rickettsia bellii-specific assay, and a Rickettsia genus-specific …

Range Expansion Of Tick Disease Vectors In North America: Implications For Spread Of Tick-Borne Disease, Daniel E. Sonenshine

Biological Sciences Faculty Publications

Ticks are the major vectors of most disease-causing agents to humans, companion animals and wildlife. Moreover, ticks transmit a greater variety of pathogenic agents than any other blood-feeding arthropod. Ticks have been expanding their geographic ranges in recent decades largely due to climate change. Furthermore, tick populations in many areas of their past and even newly established localities have increased in abundance. These dynamic changes present new and increasing severe public health threats to humans, livestock and companion animals in areas where they were previously unknown or were considered to be of minor importance. Here in this review, the geographic …