Immunology and Infectious Disease Commons^™

Defensin In The Ticks Dermacentor Variabilis And Ixodes Scapularis, Shane Michael Ceraul

Theses and Dissertations in Biomedical Sciences

This dissertation presents the identification, molecular structure and expression of defensin, an antimicrobial peptide, in the ticks, Dermacentor variabilis and Ixodes scapularis. A 624 bp cDNA molecule for defensin was cloned and sequenced from hemocytes, fat body and midgut of unstimulated D. variabilis ticks. Defensin peptide was detected only in the hemocyte lysates. These results suggest that the defensin from D. variabilis is synthesized and stored in the hemocytes, although the role of other tissues is not excluded.

The ability of the juvenile stage ticks to express the defensin gene was confirmed. Detection of the defensin transcript in all …

The Defensin Gene In Dermacentor Variabilis And Ixodes Scapularis, Katherine Corbett Seguin

Biological Sciences Theses & Dissertations

In response to microbial challenge, invertebrates rely on their innate immune response to recognize and destroy harmful pathogens. One of the primary proteins produced by the response and that has been observed in many invertebrates, including insects, mussels, and ticks, is defensin. These proteins are responsible for forming pores in the membranes of invading microbes thereby destroying them. This study examined the gene coding region for defensin in two important tick disease vectors, Dermacentor variabilis and Ixodes scapularis. PCR amplification of the genes from tick chromosomal DNA resulted in the amplification of a 225 base pair amplicon. Sequencing of …

Bolivian Ectoparasites: A New Species Of Laelapine Mite (Acari: Parasitiformes, Laelapidae) From The Rodent Neacomys Spinosus, Donald Gettinger, Scott Lyell Gardner

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Laelaps neacomydis n. sp. is described from the pelage of the rodent Neacomys spinosus collected in Bolivia. Collection records from northern Brazil, southeastern Peru, and central Bolivia indicate its wide distribution across Amazonas associated with rodents of the genus Neacomys. The formal taxonomic description and illustrations are derived from the adults (female and male). Two larger species of laelapine mites, Gigantolaelaps intermedius and L. boultoni, infest the same hosts at the same localities.

The Prevalence Of The Q-Fever Agent Coxiella Burnetii In Ticks Collected From An Animal Shelter In Southeast Georgia, John H. Smoyer Iii

College of Graduate Studies: Theses & Dissertations

Author's abstract: Q-fever is a zoonosis caused by a worldwide-distributed bacterium Coxiella burnetii. Ticks are vectors of the Q-fever agent but play a secondary role in transmission because the agent is also transmitted via aerosols. Most Q-fever studies have focused on farm animals but not ticks collected from dogs in animal shelters. In order to detect the Q-fever agent in these ticks, a nested PCR technique targeting the 16S rDNA of Coxiella burnetii was used. A collection of 450 ticks from the animal shelter were screened via nested PCR and 144 (32%) were positives. The positive PCR products were also …

An Arthropod Defensin Expressed By The Hemocytes Of The American Dog Tick, Dermacentor Variabilis (Acari: Ixodidae), Shane M. Ceraul, Daniel E. Sonenshine, Robert E. Ratzlaff, Wayne L. Hynes

Biological Sciences Faculty Publications

Both soluble and cell-mediated components are involved in the innate immune response of arthropods. Injection of Borrelia burgdorferi, the Lyme disease agent, results in the secretion of defensin into the hemolymph of the ixodid tick, Dermacentor variabilis. The presence of the peptide is observed as early as 15 min post-challenge and remains present through 18 h post-challenge. As observed in insects and soft ticks, the transcript for defensin is detected as early as 1 h post-challenge in D. variabilis. RT-PCR resulted in an amplicon of 624 bp with a 225 bp region that translates to a 74 …

Glass Capillary Tube Feeding: A Method For Infecting Nymphal Ixodes Scapularis (Acari: Ixodidae) With The Lyme Disease Spirochete Borrelia Burgdorferi, Anne H. Broadwater, Daniel E. Sonenshine, Wayne L. Hynes, Shane Ceraul, Aravinda M. De Silva

Biological Sciences Faculty Publications

We evaluated an artificial capillary feeding method to infect nymphal Ixodes scapularis (Say) ticks with Borrelia burgdorferi, the causative agent of Lyme disease. Thirty to 70% of the nymphs were infected after feeding for 2.5 h from glass capillary tubes filled with a solution of spirochetes. Capillary infection was stable and persisted in the nymphs for at least 10 d after feeding. Capillary feeding also maintained natural vector competence patterns because I. scapularis ticks acquired infection unlike Dermacentor variablis (Say), which did not become infected. Capillary infected I. scapularis nymphs were capable of transmitting the infection to naive mice …

Arthropod And Helminth Parasites From The Plains Pocket Gopher, Geomys Bursarius Bursarius From The Hosts' Northern Boundary Range In Minnesota, Monroe H. Bartel, Scott Lyell Gardner

Harold W. Manter Laboratory of Parasitology: Faculty Publications

As part of a continuing and more general study of the diversity of parasites from subterranean mammals in central North America, individuals of the Plains pocket gopher, Geomys bursarius bursarius, were collected from 7 localities in northwestern Minnesota from September 1991 through October 1996. Arthropods collected included the fleas, Opisocrostis bruneri (4 of 124, 3.20/0), Foxella ignota ignota (85 of 124, 68.50/0); the chewing louse, Geomydoecus geomydis geomydis from 98 of 124 (790/0), and larvae of the tick, Dermacentor variabilis (1 of 124, 0.8%). Nematodes found included Physaloptera limbata (2 of 118 gophers, 1.7%), Capillaria americana (4 of 118, …

Incorporation Of Carbon-14 Metabolites Into The Sex Pheromon 26-Dichlorophenol Of Dermacentor Andersoni Stiles; And The Disruption Of Pheromone Activity In D. Andersoni And D. Variabilis (Say) By Quinones, Daniel Martin Gainsburg

Biological Sciences Theses & Dissertations

The Rocky Mountain wood tick, Dermacentor andersoni Stiles, injected with (u-¹⁴c) sodium acetate or DL-(benzene ring-u-¹⁴c) tryptophan for in vivo studies, was found to produce sex pheromone, 2,6-dichlorophenol, containing ¹⁴c activity. Ambiguous results were obtained with L-(u- ¹⁴c) tyrosine, and no incorporation of ¹⁴c label into pheromone was observed with DL-(ring-u- ¹⁴c) phenylalanine or DL-(side chain-3-¹⁴c) tyrosine. Attempts were made to determine the site of synthesis, but in vitro studies proved inconclusive.

Disruption of sex pheromone activity in D. andersoni and the American dog tick, D. variabilis (Say) was achieved …

A Morphological Study Of Some Larval Ticks Of The Genus Dermacentor With Emphasis On Structures Of Possible Taxonomic Importance, Richard Grant Robertson

Theses and Dissertations

This study was undertaken to evaluate and determine morphological characteristics which might prove valuable in the identification of the larvae of the following species of ticks of the genus Dermacentor Koch: D. albipictus Packard, D. andersoni Stiles, D. hunteri Bishop, D. parumapertus Neuman, and D. variabilis Say. A taxonomic key for the identification of all of the Canadian and United States species of the larvae of the genus Dermacentor Koch cannot be constructed until specimens of D. halli and D. occidentalis have been examined. However, the followng conclusions were reached regarding the species studied: 1. Position of setae is of …

Oviposition Habits Of The Tick Dermacentor Parumapertus Neumann And Factors Influencing Egg Development, Clive D. Jorgensen

Theses and Dissertations

This paper includes data concerning the influence of relative humidity, temperature, and percentage of engorgement on the pre-oviposition period, oviposition period, post-oviposition period, and incubation period of the tick Dermacentor parumapertus Neumann. The influence of the percentage of engorgement on the oviposition period, oviposition rate, and egg number is considered. Data on the disposition and number of eggs in nature are discussed.

The Ticks Or Ixodides Of The U.S.S.R.: A Review Of The Literature, George Anastos

Harold W. Manter Laboratory of Parasitology: Library Materials

No abstract provided.