Life Sciences Commons^™

Anti-Tick Vaccine Candidate Subolesin Is Important For Blood Feeding And Innate Immune Gene Expression In Soft Ticks, Krittika Nandy, Comfort Tamakloe, Daniel E. Sonenshine, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Subolesin is a conserved molecule in both hard and soft ticks and is considered as an effective candidate molecule for the development of anti-tick vaccine. Previous studies have reported the role of subolesin in blood feeding, reproduction, development, and gene expression in hard ticks. However, studies addressing the role of subolesin in soft ticks are limited. In this study, we report that subolesin is not only important in soft tick Ornithodoros turicata americanus blood feeding but also in the regulation of innate immune gene expression in these ticks. We identified and characterized several putative innate immune genes including Toll, Lysozyme …

Editorial: Tick Saliva: Secret To Blood Feeding Success, Daniel E. Sonenshine, Patricia A. Nuttall, Sukanya Narasimhan

Biological Sciences Faculty Publications

No abstract provided.

Rickettsial Pathogen Perturbs Tick Circadian Gene To Infect The Vertebrate Host, Supreet Khanal, Vikas Taank, John F. Anderson, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ixodes scapularis is a medically important tick that transmits several microbes to humans, including rickettsial pathogen Anaplasma phagocytophilum. In nature, these ticks encounter several abiotic factors including changes in temperature, humidity, and light. Many organisms use endogenously generated circadian pathways to encounter abiotic factors. In this study, we provide evidence for the first time to show that A. phagocytophilum modulates the arthropod circadian gene for its transmission to the vertebrate host. We noted a circadian oscillation in the expression of arthropod clock, bmal1, period and timeless genes when ticks or tick cells were exposed to alternate 12 h …

Identification Of A Rickettsial Endosymbiont In A Soft Tick Ornithodoros Turicata Americanus, Lichao Liu, Daniel E. Sonenshine, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Bacterial endosymbionts are abundantly found in both hard and soft ticks. Occidentia massiliensis, a rickettsial endosymbiont, was first identified in the soft tick Ornithodoros sonrai collected from Senegal and later was identified in a hard tick Africaniella transversale. In this study, we noted the presence of Occidentia species, designated as Occidentia-like species, in a soft tick O. turicata americanus. Sequencing and phylogenetic analyses of the two genetic markers, 16S rRNA and groEL confirmed the presence of Occidentia-like species in O. turicata americanus ticks. The Occidentia-like species was noted to be present in all developmental stages …

Biology And Molecular Biology Of Ixodes Scapularis, Daniel E. Sonenshine, Ladislav Šimo, Justin D. Radolf (Ed.), D. Scott Samuels (Ed.)

Biological Sciences Faculty Publications

This chapter describes the biology of the tick Ixodes scapularis in relation to its role as the vector of the Lyme disease agent, Borrelia burgdorferi. Following a review of the internal anatomy of the tick, we review basic molecular processes that contribute to an understanding of the dynamics of the tick's specialized parasitic processes, including attachment behavior, salivation; silencing of host anti-inflammatory responses to enable blood ingestion at the dermal feeding site; hemoglobin digestion and reproduction. The chapter is divided into three parts: 1) systematic and anatomical characteristics of ticks; 2) host finding, attachment, salivary disruption of host defenses, blood …

Discovery Of Exosomes From Tick Saliva And Salivary Glands Reveals Therapeutic Roles For Cxcl12 And Il-8 In Wound Healing At The Tick-Human Skin Interface, Wenshuo Zhou, Faizan Tahir, Joseph Che-Yen Wang, Michael Woodson, Michael B. Sherman, Shahid Karim, Girish Neelakanta, Hameeda Sultana

Biological Sciences Faculty Publications

Ticks secrete various anti-coagulatory, anti-vasoconstrictory, anti-inflammatory, and anti-platelet aggregation factors in their saliva at the bite site during feeding to evade host immunological surveillance and responses. For the first time, we report successful isolation of exosomes (small membrane-bound extracellular signaling vesicles) from saliva and salivary glands of partially fed or unfed ixodid ticks. Our data showed a novel role of these in vivo exosomes in the inhibition of wound healing via downregulation of C-X-C motif chemokine ligand 12 (CXCL12) and upregulation of interleukin-8 (IL-8). Cryo-electron microscopy (cryo-EM) analysis revealed that tick saliva and salivary glands are composed of heterogeneous populations …

Tick-Borne Flavivirus Inhibits Sphingomyelinase (Issmase), A Venomous Spider Ortholog To Increase Sphingomyelin Lipid Levels For Its Survival In Ixodes Scapularis Ticks, Pravesh Regmi, Supreet Khanal, Girish Neelakanta, Hameda Sultana

Biological Sciences Faculty Publications

Our previous study showed that cells from medically important arthropods, such as ticks, secrete extracellular vesicles (EVs) including exosomes that mediate transmission of flavivirus RNA and proteins to the human cells. Understanding the molecular determinants and mechanism(s) of arthropod-borne flavivirus transmission via exosome biogenesis is very important. In this current study, we showed that in the presence of tick-borne Langat Virus (LGTV; a member of tick-borne encephalitis virus complex), the expression of arthropod IsSMase, a sphingomyelinase D (SMase D) that catalyzes the hydrolytic cleavage of substrates like sphingomyelin (SM) lipids, was significantly reduced in both Ixodes scapularis ticks (in vivo) …

Factors Affecting The Microbiome Of Ixodes Scapularis And Amblyomma Americanum, R. Jory Brinkerhoff, Chris Clark, Kelly Ocasio, David T. Gauthier, Wayne L. Hynes

Biological Sciences Faculty Publications

The microbial community composition of disease vectors can impact pathogen establishment and transmission as well as on vector behavior and fitness. While data on vector microbiota are accumulating quickly, determinants of the variation in disease vector microbial communities are incompletely understood. We explored the microbiome of two human-biting tick species abundant in eastern North America (Amblyomma americanum and Ixodes scapularis) to identify the relative contribution of tick species, tick life stage, tick sex, environmental context and vertical transmission to the richness, diversity, and species composition of the tick microbiome. We sampled 89 adult and nymphal Ixodes scapularis (N …

A Simple, Inexpensive Method For Mark-Recapture Of Ixodid Ticks, Alexis White, Robin Minch, Lindsey Bidder, Holly Gaff

Biological Sciences Faculty Publications

Mark-recapture techniques have been widely used and specialized to study organisms throughout the field of biology. To mark-recapture ticks (Ixodida), we have created a simple method to mark ticks using nail polish applied with an insect pin secured in a pencil that allows for a variety of questions to be answered. For measuring tick control efficacy, estimating population estimates, or measuring movement of ticks, this inexpensive mark-recapture method has been easily applied in the field and in the lab to provide useful data to answer a variety of questions about ticks.

Molecular Investigation And Phylogeny Of Species Of The Anaplasmataceae Infecting Animals And Ticks In Senegal, Mustapha Dahmani, Bernard Davoust, Masse Sambou, Hubert Bassene, Pierre Scandola, Tinhinene Ameur, Didier Raoult, Florence Feenollar, Oleg Mediannikov

Biological Sciences Faculty Publications

Background: Our study aimed to assess the diversity of the species of Anaplasmataceae in Senegal that infect animals and ticks in three areas: near Keur Momar Sarr (northern region), Dielmo and Diop (Sine Saloum, central region of Senegal), and in Casamance (southern region of Senegal).

Methods: A total of 204 ticks and 433 blood samples were collected from ruminants, horses, donkeys and dogs. Ticks were identified morphologically and by molecular characterization targeting the 12S rRNA gene. Molecular characterization of species of Anaplasmataceae infecting Senegalese ticks and animals was conducted using the 23S rRNA, 16S rRNA, rpoB and groEL genes.

Results: …

Dynamics Of Two Pathogens In A Single Tick Population, Alexis White, Elsa Schaefer, Chelsea Wright-Thompson, Christopher M. Kribs, Holly Gaff

Biological Sciences Faculty Publications

A mathematical model for a two-pathogen, one-tick, one-host system is presented and explored. The goal of this model is to determine how long an invading pathogen persists within a tick population in which a resident pathogen is already established. The numerical simulations of the model demonstrate the parameter ranges that allow for coexistence of the two pathogens. Sensitivity analysis highlights the importance of vector-borne, tick-to-host, transmission rates on the invasion reproductive number and persistence of the pathogens over time. The model is then applied to a case study based on a reclaimed swampland field site in southeastern Virginia using field …

Modelling The Effects Of Habitat And Hosts On Tick Invasions, Robyn M. Nadolny, Holly D. Gaff

Biological Sciences Faculty Publications

Many tick species are invading new areas because of anthropogenic changes in the landscape, shifting climatic variables and increasing populations of suitable host species and tick habitat. However, the relative influences of habitat and hosts in tick dispersal and tick population establishment remain in question. A spatially explicit agent-based model was developed to explore the spatio-temporal dynamics of a generic tick population in the years immediately following the introduction of ticks into a novel environment. The general model was then adapted to investigate a case study of two recent tick species invasions into the Mid-Atlantic United States. The recent simultaneous …

Human Rickettsial Pathogen Modulates Arthropod Organic Anion Transporting Polypeptide And Tryptophan Pathway For Its Survival In Ticks, Vikas Taank, Shovan Dutta, Amrita Dasgupta, Durland Fish, John F. Anderson, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

The black-legged tick Ixodes scapularis transmits the human anaplasmosis agent, Anaplasma phagocytophilum. In this study, we show that A. phagocytophilum specifically up-regulates I. scapularis organic anion transporting polypeptide, isoatp4056 and kynurenine amino transferase (kat), a gene involved in the production of tryptophan metabolite xanthurenic acid (XA), for its survival in ticks. RNAi analysis revealed that knockdown of isoatp4056 expression had no effect on A. phagocytophilum acquisition from the murine host but affected the bacterial survival in tick cells. Knockdown of the expression of kat mRNA alone or in combination with isoatp4056 mRNA significantly affected A. phagocytophilum survival …

Ticks Elicit Variable Fibrinogenolytic Activities Upon Feeding On Hosts With Different Immune Backgrounds, Ashish Vora, Vikas Taank, John F. Anderson, Durland Fish, Daniel E. Sonenshine, John D. Catravas, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ticks secrete several anti-hemostatic factors in their saliva to suppress the host innate and acquired immune defenses against infestations. Using Ixodes scapularis ticks and age-matched mice purchased from two independent commercial vendors with two different immune backgrounds as a model, we show that ticks fed on immunodeficient animals demonstrate decreased fibrinogenolytic activity in comparison to ticks fed on immunocompetent animals. Reduced levels of D-dimer (fibrin degradation product) were evident in ticks fed on immunodeficient animals in comparison to ticks fed on immunocompetent animals. Increased engorgement weights were noted for ticks fed on immunodeficient animals in comparison to ticks fed on …

Mevalonate-Farnesal Biosynthesis In Ticks: Comparative Synganglion Transcriptomics And A New Perspective, Jiwei Zhu, Sayed M. Khalil, Robert D. Mitchell, Brooke W. Bissinger, Noble Egekwu, Daniel E. Sonenshine, R. Michael Roe

Biological Sciences Faculty Publications

Juvenile hormone (JH) controls the growth, development, metamorphosis, and reproduction of insects. For many years, the general assumption has been that JH regulates tick and other acarine development and reproduction the same as in insects. Although researchers have not been able to find the common insect JHs in hard and soft tick species and JH applications appear to have no effect on tick development, it is difficult to prove the negative or to determine whether precursors to JH are made in ticks. The tick synganglion contains regions which are homologous to the corpora allata, the biosynthetic source for JH in …

Evidence Of Female Sex Pheromones And Characterization Of The Cuticular Lipids Of Unfed, Adult Male Versus Female Blacklegged Ticks, Ixodes Scapularis, Ann L. Carr, Daniel E. Sonenshine, John B. Strider Jr., R. Michael Roe

Biological Sciences Faculty Publications

Copulation in I. scapularis involves physical contact between the male and female (on or off the host), male mounting the female, insertion/maintenance of the male chelicerae in the female genital pore (initiates spermatophore production), and the transfer of the spermatophore by the male into the female genital pore. Bioassays determined that male mounting behavior/chelicerae insertion required direct contact with the female likely requiring non-volatile chemical cues with no evidence of a female volatile sex pheromone to attract males. Unfed virgin adult females and replete mated adult females elicited the highest rates of male chelicerae insertion with part fed virgin adult …

Anaplasma Marginale Actively Modulates Vacuolar Maturation During Intracellular Infection Of Its Tick Vector, Dermacentor Andersoni, Foregivemore Magunda, Chelsea Wright Thompson, David A. Schneider, Susan M. Noh

Biological Sciences Faculty Publications

ABSTRACT Tick-borne transmission of bacterial pathogens in the order Rickettsiales is responsible for diverse infectious diseases, many of them severe, in humans and animals. Transmission dynamics differ among these pathogens and are reflected in the pathogen-vector interaction. Anaplasma marginale has been shown to establish and maintain infectivity within Dermacentor spp. for weeks to months while escaping the complex network of vacuolar peptidases that are responsible for digestion ofthe tick blood meal. How this prolonged maintenance of infectivity in a potentially hostile environment is achieved has been unknown. Using the natural vector Dermacentor andersoni, we demonstrated that A. marginale …

Quantitative Factors Proposed To Influence The Prevalence Of Canine Tick-Bourne Disease Agents In The United States, Roger W. Stich, Byron L. Blagburn, Dwight D. Bowman, Christopher Carpenter, M. Roberto Cortinas, Sidney A. Ewing, Desmond Foley, Holly Gaff, Graham J. Hickling, R. Ryan Lash

Biological Sciences Faculty Publications

The Companion Animal Parasite Council hosted a meeting to identify quantifiable factors that can influence the prevalence of tick-borne disease agents among dogs in North America. This report summarizes the approach used and the factors identified for further analysis with mathematical models of canine exposure to tick-borne pathogens.

Comparison Of Phenology And Pathogen Prevalence, Including Infection With The Ehrlichia Muris-Like (Eml) Agent, Of Ixodes Scapularis Removed From Soldiers In The Midwestern And Northeastern United States Over A 15 Year Period (1997-2012), Ellen Stromdahl, Sarah Hamer, Sarah Jenkins, Lynne Sloan, Phillip Williamson, Erik Foster, Robyn Nadolny, Chad Elkins, Mary Vince, Bobbi Pritt

Biological Sciences Faculty Publications

Background: Since 1997, human-biting ticks submitted to the Department of Defense Human Tick Test Kit Program (HTTKP) of the US Army Public Health Command have been tested for pathogens by PCR. We noted differences in the phenology and infection prevalence among Ixodes scapularis ticks submitted from military installations in different geographic regions. The aim of this study was to characterize these observed differences, comparing the phenology and pathogen infection rates of I. scapularis submitted from soldiers at two sites in the upper Midwest ( Camp Ripley, MN, and Ft. McCoy, WI) and one site in the northeastern US (Ft. Indiantown …

Ehrlichia And Spotted Fever Group Rickettsiae Surveillance In Amblyomma Americanum In Virginia Through Use Of A Novel Six-Plex Real-Time Pcr Assay, David N. Gaines, Darwin J. Operario, Suzanne Stroup, Ellen Stromdahl, Chelsea Wright, Holly Gaff, James Broyhill, Joshua Smith, Douglas E. Norris, Tyler Henning, Agape Lucas, Eric Houpt

Biological Sciences Faculty Publications

The population of the lone star tick Amblyomma americanum has expanded in North America over the last several decades. It is known to be an aggressive and nondiscriminatory biter and is by far the most common human-biting tick encountered in Virginia. Few studies of human pathogen prevalence in ticks have been conducted in our state since the mid-twentieth century. We developed a six-plex real-time PCR assay to detect three Ehrlichia species (E. chaffeensis, E. ewingii, and Panola Mountain Ehrlichia) and three spotted fever group Rickettsiae (SFGR; R. amblyommii, R. parkeri, and R. rickettsii …

Ixodes Affinis (Acari: Ixodidae) In Southeastern Virginia And Implications For The Spread Of Borrelia Burgdorferi, The Agent Of Lyme Disease, Robyn M. Nadolny, Chelsea L. Wright, Wayne L. Hynes, Daniel E. Sonenshine, Holly Gaff

Biological Sciences Faculty Publications

Ixodes affinis Neumann is a hard-bodied (ixodid) tick known to be a competent vector for Borrelia burgdorferi, the agent of Lyme disease, and agents of other human diseases (Keirans et al. 1999). Ixodes affinis has been reported in Florida, Georgia, and South Carolina and throughout coastal North Carolina (Clark et al. 1998, Harrison et al. 2010). Harrison et al. (2010) indicated that I. affinis was established throughout the coastal plain of North Carolina up to the Virginia border and suggested that I. affinis might occur in Virginia.

Results From A Mathematical Model For Human Monocytic Ehrlichiosis, H. Gaff, L. Gross, E. Schaefer

Biological Sciences Faculty Publications

Human monocytic ehrlichiosis (Ehrlichia chaffeensis), HME, is a tick-transmitted, rickettsial disease that has recently increased substantially in the USA from 142 reported cases in 2001 to 506 reported cases in 2005 [1,2]. There have been increasing surveys of tick populations over the past 10 years that have in turn supported the development of models for tick-borne disease transmission. Resulting HME models [3] suggest the importance of metapopulation structures, landscape environment parameters and periodic climatic effects in predicting the dynamics of HME transmission and the efficacy of control efforts, such as the reduction of the tick population through acaricide …

Tick Pheromones And Their Use In Tick Control, Daniel E. Sonenshine

Biological Sciences Faculty Publications

Tick pheromones that regulate assembly, attraction/aggregation/attachment, and mating behavior have been described. Most of the compounds regulating these behaviors are purines, substituted phenols, or cholesteryl esters. Other pheromonal compounds include organic acids, hematin, or ecdysteroids. Novel devices have been developed that combine the specific compounds comprising these pheromones with an acaricide. When applied to tick-infested vegetation or directly to the body surfaces of livestock or companion animals, these devices are effective for tick control. This review summarizes the current state of knowledge of tick pheromones. In addition, this review also presents examples illustrating how devices using tick pheromones can offer …

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 …