Life Sciences Commons^™

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 …

Tick Transmission Of Borrelia Burgdorferi To The Murine Host Is Not Influenced By Environmentally Acquired Midgut Microbiota, Sukanya Narasimhan, Nallakkandi Rajeevan, Morven Graham, Ming-Jie Wu, Kathleen Deponte, Solenne Marion, Orlanne Masson, Anya J. O'Neal, Daniel E. Sonenshine, Erol Fikrig

Biological Sciences Faculty Publications

Background

Ixodes scapularis is the predominant tick vector of Borrelia burgdorferi, the agent of Lyme disease, in the USA. Molecular interactions between the tick and B. burgdorferi orchestrate the migration of spirochetes from the midgut to the salivary glands—critical steps that precede transmission to the vertebrate host. Over the last decade, research efforts have invoked a potential role for the tick microbiome in modulating tick-pathogen interactions.

Results

Using multiple strategies to perturb the microbiome composition of B. burgdorferi-infected nymphal ticks, we observe that changes in the microbiome composition do not significantly influence B. burgdorferi migration from the midgut, invasion of …

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 …

Double Anus In An Ixodes Scapularis Nymph, A Medically Important Tick Vector, Vikas Taank, Frank A. Lattanzio, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Background: Ixodes scapularis ticks are medically important arthropod vectors that transmit several pathogens to humans. The observations of morphological abnormalities, including nanism, missing leg, extra leg, and gynandromorphism, have been reported in these ticks. In this study, we report the presence of two anuses in a laboratory-reared I. scapularis nymph.

Results: Larval ticks were allowed to feed on mice and to molt to nymphs. Two anuses were observed in one of the freshly molted nymphs. Stereo and scanning electron microscopy confirmed the presence of two anuses in one nymph within a single anal groove.

Conclusions: This report confirms the rare …

Lymesim 2.0: An Updated Simulation Of Blacklegged Tick (Acari: Ixodidae) Population Dynamics And Enzootic Transmission Of Borrelia Burgdorferi (Spirochaetales: Spirochaetaceae), Holly Gaff, Rebecca J. Eisen, Lars Eisen, Robyn Nadolny, Jenna Bjork, Andrew J. Monaghan

Biological Sciences Faculty Publications

Lyme disease is the most commonly reported vector-borne disease in the United States, and the number of cases reported each year continues to rise. The complex nature of the relationships between the pathogen (Borrelia burgdorferi sensu stricto), the tick vector (Ixodes scapularis Say), multiple vertebrate hosts, and numerous environmental factors creates challenges for understanding and predicting tick population and pathogen transmission dynamics. LYMESIM is a mechanistic model developed in the late 1990s to simulate the life-history of I. scapularis and transmission dynamics of B. burgdorferi s.s. Here we present LYMESIM 2.0, a modernized version of LYMESIM, that includes …

Characterization Of Tick Organic Anion Transporting Polypeptides (Oatps) Upon Bacterial And Viral Infections, Vikas Taank, Wenshou Zhou, Xuran Zhuang, John F. Anderson, Utpal Pal, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Background: Ixodes scapularis organic anion transporting polypeptides (OATPs) play important roles in tickrickettsial pathogen interactions. In this report, we characterized the role of these conserved molecules in ticks infected with either Lyme disease agent Borrelia burgdorferi or tick-borne Langat virus (LGTV), a pathogen closely related to tick-borne encephalitis virus (TBEV).

Results: Quantitative real-time polymerase chain reaction analysis revealed no significant changes in oatps gene expression upon infection with B. burgdorferi in unfed ticks. Synchronous infection of unfed nymphal ticks with LGTV in vitro revealed no significant changes in oatps gene expression. However, expression of specific oatps was significantly downregulated upon …

Review: Application Of Tick Control Technologies For Blacklegged, Lone Star, And American Dog Ticks, Alexis White, Holly Gaff

Biological Sciences Faculty Publications

Tick population control technologies have been studied for several decades but no method is successful in all situations. The success of each technology depends on tick species identity and abundance, host species identity and abundance, phenology of both ticks and hosts, geographic region, and a multitude of other factors. Here we review current technologies, presenting an overview of each and its effect on three common tick species in the eastern United States: blacklegged ticks (Ixodes scapularis (Say; Ixodida: Ixodidae)), lone star ticks (Amblyomma americanum (Linnaeus; Ixodida: Ixodidae)), and American dog ticks (Dermacentor variabilis (Say; Ixodida: Ixodidae)). Moreover, …

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 …

Ticks, Ixodes Scapularis, Feed Repeatedly On White-Footed Mice Despite Strong Inflammatory Response: An Expanding Paradigm For Understanding Tick-Host Interactions, Jennifer M. Anderson, Ian N. Moore, Bianca M. Nagata, José M.C. Ribeiro, Jesus G. Valenzuela, Daniel E. Sonenshine

Biological Sciences Faculty Publications

Ticks transmit infectious agents including bacteria, viruses and protozoa. However, their transmission may be compromised by host resistance to repeated tick feeding. Increasing host resistance to repeated tick bites is well known in laboratory animals, including intense inflammation at the bite sites. However, it is not known whether this also occurs in wild rodents such as white-footed mice, Peromyscus leucopus, and other wildlife, or if it occurs at all. According to the "host immune incompetence" hypothesis, if these mice do not have a strong inflammatory response, they would not reject repeated tick bites by Ixodes scapularis. To test …

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 …

Tick Genome Assembled: New Opportunities For Research On Tick-Host-Pathogen Interactions, Jose De La Fuente, Robert M. Waterhouse, Daniel E. Sonenshine, R. Michael Roe, Jose M. Ribeiro, David B. Sattelle, Catherine A. Hill

Biological Sciences Faculty Publications

As tick-borne diseases are on the rise, an international effort resulted in the sequence and assembly of the first genome of a tick vector. This result promotes research on comparative, functional and evolutionary genomics and the study of tick-host-pathogen interactions to improve human, animal and ecosystem health on a global scale.

Single-Tube Real-Time Pcr Assay For Differentiation Of Ixodes Affinis And Ixodes Scapularis, Chelsea L. Wright, Wayne L. Hynes, Breanna T. White, Mindy N. Marshall, Holly D. Gaff, David T. Gauthier

Biological Sciences Faculty Publications

Ixodes affinis Neumann (1899) and Ixodes scapularis Say (1821) are tick vectors of the etiologic agent of Lyme disease, Borrelia burgdorferi sensu stricto. Ixodes affinis and I. scapularis are morphologically very similar, and as they are sympatric in the mid- and south-Atlantic U.S. coastal states, their accurate identification is crucial to studies of disease and vector ecology in this area. This work describes a rapid, single-tube SYBR® Green-based real-time PCR assay for differentiation of I. affinis and I. scapularis at all life stages. The assay employs 2 pairs of species specific primers directed against the internal transcribed spacer 2 (ITS2) …

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 …

Chemical Composition Of Some Components Of The Arrestment Pheromone Of The Black-Legged Tick, Ixodes Scapularis (Acari : Ixodidae) And Their Use In Tick Control, Daniel E. Sonenshine, Trevor Adams, Sandra A. Allan, John Mclaughlin, Francis X. Webster

Biological Sciences Faculty Publications

Chemical analysis (high-performance liquid chromatography) and bioassay demonstrated the presence of compounds that seem to be components of the Ixodes scapularis arrestment pheromone. Only two purines, guanine and xanthine, were found in acidified saline extracts made from cast skins after molting of fed nymphs, fed larvae, and fecal/excretory exudates deposited by unfed adults on substrates in their environment. The ratio of guanine to xanthine was 10.6:1 in an extract from the nymphal skins versus 0.95:1 in an extract from the larval skins. Guanine, xanthine, and traces of a third purine, tentatively identified as 8-azaguanine, were found in extracts made from …

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 …

Identification Of A Defensin From The Hemolymph Of The American Dog Tick, Dermacentor Variabilis, Robert Johns, Daniel E. Sonenshine, Wayne L. Hynes

Biological Sciences Faculty Publications

Hemolymph from partially fed virgin Dermacentor variabilis females was collected following Borrelia burgdorferi challenge and assayed for antimicrobial activity against Bacillus subtilis and B. burgdorferi. A small inducible cationic peptide was identified by SDS-PAGE in the hemolymph of these ticks as early as 1h post challenge. Following purification by a three-step procedure involving sequential SepPak elution, reversed phase high performance liquid chromatography (RP-HPLC) and gel electrophoresis, the yield of the active peptide was approximately 0.1% of the total protein in the hemolymph plasma. The molecular weight, 4.2kDa, was determined by MALDI-TOF mass spectrometry. N-terminal sequencing by the Edman degradation …

Contrasts In Tick Innate Immune Responses To Borrelia Burgdorferi Challenge: Immuno-Tolerance In Ixodes Scapularis Versus Immunocompetence In Dermacentor Variabilis (Acari: Ixodidae)., Robert Johns, Jun Ohnishi, Anne Broadwater, Daniel E. Sonenshine, Aravinda M. Desilva, Wayne L. Hynes

Biological Sciences Faculty Publications

The blacklegged tick, Ixodes scapularis Say, transmits the Lyme disease spirochete (Borrelia burgdorferi), whereas the American dog tick, Dermacentor variabilis (Say), is unable to transmit the bacterium. We compared the innate immune response of these ticks against spirochetes directly inoculated into the hemocoel cavity of ticks. In I. scapularis, some Borrelia were found associated with hemocytes, while numerous other spiral-shaped, intact bacteria remained free in the hemolymph. In contrast, in D. variabilis only remnants of the bacteria were evident in the hemolymph, indicating lysis; intact spirochetes were rare. Spirochetes were observed bound to or within the organs …