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Full-Text Articles in Veterinary Medicine
Infection Potential Of Rickettsia Felis Via Ingestion, Matthew M. Schexnayder
Infection Potential Of Rickettsia Felis Via Ingestion, Matthew M. Schexnayder
LSU Master's Theses
Rickettsia felis is the etiologic agent of flea-borne spotted fever (FBSF) in humans and a poorly described cause of fever in animals. It is transmitted by its primary arthropod vector and reservoir host, the cat flea Ctenocephalides felis. Known routes of Rickettsia felis transmission between Rickettsia felis-infected cat fleas and vertebrate hosts include cutaneous bites and contamination of cutaneous wounds with infective flea feces. The bulk of FBSF infections occur in young children in Africa, though infections of people at all ages all over the world have been confirmed. As mammals and young children frequently come into contact …
Rickettsia Felis, Transmission Mechanisms Of An Emerging Flea-Borne Rickettsiosis, Lisa Diane Brown
Rickettsia Felis, Transmission Mechanisms Of An Emerging Flea-Borne Rickettsiosis, Lisa Diane Brown
LSU Doctoral Dissertations
Rickettsia felis is an emerging insect-borne rickettsial pathogen and the causative agent of flea-borne spotted fever. First described as a human pathogen from the United States in 1991, R. felis is now identified throughout the world and considered a common cause of fever in Africa. The cosmopolitan distribution of this pathogen is credited to the equally widespread occurrence of cat fleas (Ctenocephalides felis), the primary vector and reservoir of R. felis. Additionally, R. felis has been identified in other hematophagous arthropods (including numerous species of fleas, ticks, mosquitoes, and mites). Most transmission cycles of pathogenic Rickettsia include transovarial and transstadial …
Identification And Characterization Of A Relish-Type Nf-Kb, Dvrelish In Dermacentor Variabilis, The American Dog Tick, Victoria Irene Verhoeve
Identification And Characterization Of A Relish-Type Nf-Kb, Dvrelish In Dermacentor Variabilis, The American Dog Tick, Victoria Irene Verhoeve
LSU Doctoral Dissertations
Ticks are important worldwide as vectors of bacteria, viruses, and parasites. Pathogenic and non-pathogenic Spotted fever group (SFG) Rickettsia are maintained and transmitted by ticks with specific hard tick-Rickettsia pairings evident in nature. The pathogenic SFG Rickettsia rickettsii is transmitted by the hard tick Dermacentor variabilis. In response to infection, D. variabilis is known differentially respond to SFG Rickettsia infection. The mechanisms of differential immune induction are currently unknown, and are likely involved in the establishment of specific tick-SFG Rickettsia pairings. It was hypothesized that the level of response by D. variabilis to SFG Rickettsia occurs in a species-specific manner, …
Characterization Of Rickettsial Infection Dynamics Within Dermacentor Variabilis And Amblyomma Maculatum, Emma Kate Harris
Characterization Of Rickettsial Infection Dynamics Within Dermacentor Variabilis And Amblyomma Maculatum, Emma Kate Harris
LSU Doctoral Dissertations
Spotted fever group (SFG) Rickettsia are primarily associated with their reservoir host and vector, the tick. Rickettsial colonization and maintenance within the arthropod is a key component of vector competence and pathogen transmission to the mammalian host. Contemporary detection of novel tick hosts for rickettsial species, combined with an unprecedented rise in human cases of SFG rickettsiosis, necessitates a deeper understanding of tick/Rickettsia interactions. The hypothesis for this work is that if primary tick/Rickettsia pairings do not exist then rickettsial determinants account for primary vector/pathogen relationships. To this end, Dermacentor variabilis and Amblyomma maculatum ticks were exposed to R. rickettsii, …
Signal Transduction And Rickettsial Infection Of Tick Cells, Natthida Petchampai
Signal Transduction And Rickettsial Infection Of Tick Cells, Natthida Petchampai
LSU Doctoral Dissertations
Spotted fever group (SFG) Rickettsia are obligate intracellular bacteria that are carried by ticks. One such tick, Dermacentor variabilis is a vector for the etiologic agent of Rocky Mountain spotted fever, R. rickettsii. These ticks also carry a non-pathogenic R. montanensis, the agent used in this study. Interestingly, field data collected from infected D. variabilis throughout the United States revealed that the majority of Rickettsia in ticks are non-pathogenic species such as R. montanensis. Although ticks serve as both vector and reservoir hosts for SFG Rickettsia, many questions regarding tick-Rickettsia interaction remain unresolved. Therefore, the overall goal of this research …
Influence Of Tick Transmission On The Host Response To Rickettsial Infection, Soma Chowdhury
Influence Of Tick Transmission On The Host Response To Rickettsial Infection, Soma Chowdhury
LSU Master's Theses
Several members of the spotted fever group (SFG) of Rickettsia are transmitted to the host through infected ixodid (hard) ticks, which can serve as both vectors and reservoirs. Multiple studies have demonstrated that ticks secrete proteins into the bite site of the host that suppress innate and adaptive immune responses. While this suppression of immune responses is beneficial to the tick, it may also be beneficial to the transmitted Rickettsia. We hypothesize that Rickettsia utilize the tick’s ability to alter the host immune response at the tick feeding site to successfully establish infection. In the current study, we analyzed how …
Plasmid-Mediated Expression Of Foreign Genes In Ehrlichia Canis, Langston Dolphus Hull
Plasmid-Mediated Expression Of Foreign Genes In Ehrlichia Canis, Langston Dolphus Hull
LSU Doctoral Dissertations
Ehrlichia canis is the etiologic agent of “tropical canine pancytopenia”, or canine ehrlichiosis. The impetus for this research was to overcome the lack of any reliable means of elucidating the genetic profiles of these illusive and historically difficult to manipulate organisms. The use of a broad-host range plasmid greatly facilitated the determination of an electro-transformation protocol. The transforming plasmid possesses a chloramphenicol antibiotic resistance gene marker (chloramphenicol acetyltransferase [CAT] gene), and a visual reporter gene marker, the Green Fluorescent Protein (GFP) gene. With primer sets designed to specifically amplify these two plasmid encoded gene markers, thus verifying the presence of …