Tick-Host-Pathogen Interactions


Book Description

Besides causing direct damage associated with blood feeding and in some cases through the excretion of toxins with their saliva, the main relevance of ticks lies in the wide variety of pathogens that they can transmit, including viruses, bacteria, protozoa and helminths. Owing to socioeconomic and environmental changes, tick distribution is changing with incursions of ticks and tick-borne diseases occurring in different regions of the world when the widespread deployment of chemical acaricides and repellents has led to the selection of resistance in multiple populations of ticks. New approaches that are environmentally sustainable and that provide broad protection against current and future tick-borne pathogen (TBP) are thus urgently needed. Such development, however, requires improved understanding of factors resulting in vector competence and tick-host-pathogen interactions. This Research Topic provides an overview of known molecular tick-host-pathogen interactions for a number of TBPs and highlights how this knowledge can contribute to novel control and prevention strategies for tick-borne diseases.




Tick-Host-Pathogen Interactions


Book Description

Besides causing direct damage associated with blood feeding and in some cases through the excretion of toxins with their saliva, the main relevance of ticks lies in the wide variety of pathogens that they can transmit, including viruses, bacteria, protozoa and helminths. Owing to socioeconomic and environmental changes, tick distribution is changing with incursions of ticks and tick-borne diseases occurring in different regions of the world when the widespread deployment of chemical acaricides and repellents has led to the selection of resistance in multiple populations of ticks. New approaches that are environmentally sustainable and that provide broad protection against current and future tick-borne pathogen (TBP) are thus urgently needed. Such development, however, requires improved understanding of factors resulting in vector competence and tick-host-pathogen interactions. This Research Topic provides an overview of known molecular tick-host-pathogen interactions for a number of TBPs and highlights how this knowledge can contribute to novel control and prevention strategies for tick-borne diseases.







Ticks and Tick-Borne Pathogens


Book Description

This volume contains the Proceedings of the 4th International Conference on Ticks and Tick-borne Pathogens (TTP-4), held in Banff, Alberta, Canada, from 21 to 26 July 2002. TTP-4 continues an important tradition established in 1992 at the first Conference in St. Paul, Minnesota, USA, and developed subsequently at the Kruger National Park, South Africa (1995) and the High Tatra Mountains, Slovakia (1999). The 31 papers published in this special issue are divided between six sessions, with a keynote address as an introduction. The first session, which deals with biosystematics, genomics and proteomics of ticks, contains the most recent world list of valid tick names. The papers deal with a broad range of tick-host-pathogen interactions, including remote sensing and mapping of ticks and tick-borne pathogens as well as practical aspects of tick control. It is recommended reading for anyone working on ticks and tick-borne pathogens, which are of increasing medical and veterinary importance worldwide.




The biology and ecology of ticks shape the potential for the transmission of zoonotic pathogens.


Book Description

Ticks are noticeable by the high diversity of pathogens they can transmit, most of them with implications in human and animal health. Ticks are arachnids, meaning that they do not share the biological and ecological features of the mosquitoes and other parasitic Diptera. The natural foci of tick-borne pathogens may be as large as a continent, or be restricted to small portions of a country, without apparently too many similar features. The life cycle of the ticks involved three developing instars. The precise relationships of ticks and their hosts, the specific seasonal pattern of activity of ticks, and the still poorly known molecular relationships between ticks and the pathogens they can transmit, make these vectors a specially fecund field of research. Importantly, extensive studies on the biological and ecological relationships of ticks and abiotic (climate and vegetation) conditions have revealed the fine-tuning of the ticks and the pathogens they transmit, together with the biological effects of host and the driving features by the climate. The studies on tick-transmitted pathogens have been on the rise in the last years. There is a growing interest in understand the somewhat complex relationships between the landscape, the climate, the vectors and the pathogens, because the concerns of spread, probably driven by subtle changes in climate and man made alterations of the landscape. Studies on Lyme borreliosis are addressing the interesting issue of the relationships between the climate, the tick activity patterns, and the selection of strains according to the reservoir availability. Furthermore, the expanding field of habitat suitability modeling has been applied with different degrees of success to evaluate and quantify the risk of disease transmission. In such exponentially growing field, revisionary books are clearly welcome additions to the bibliographical tools of researchers. It is however necessary the compilation of works devoted to explore the tip of the iceberg in the field of research. In this Research Topic, we wish to summarize and review the studies on ecology, molecular biology, and tick-host-pathogens interactions, provided to resolve the important issues of ticks and pathogens. We want not only the results obtained by newly developed molecular tools, but rigorous reviews of the most recent advances in these issues. This Topic will cover aspects of both human and animal health, with special interest on zoonoses. Aspects of the biology of the ticks, as affecting the transmission of pathogens, are of special interest in this Topic. Studies on ticks of the poorly known family Argasidae, as related to their involvement on pathogen transmission, are especially welcome. We also wish to describe the perspective of the field in the future. Finally, the presentation of ongoing original works is greatly encouraged.







Elucidating the Molecular Function of Reprolysin Metalloproteases in Tick-host-pathogen Interactions


Book Description

Ticks are ectoparasites that attach to their host for many days to weeks, feeding to engorgement and continuing their species life cycle. The mechanisms behind the successful feeding and manipulation of host immune responses have been associated with the secretion of their specialized saliva. Tick saliva includes a variety of modulatory molecules that must disrupt and counteract defense mechanisms, including a variety of proteases. Reprolysin Metalloproteases, in the Zn2+ dependent family, is secreted as a proenzyme and is shown to have proteolytic activity, degrading fibrinogen and gelatinase activity, as well as disturbing homeostasis.12 Previous work with the Amblyomma americanum sialotranscriptome identified over 40 metalloproteases secreted in the saliva during the ticks' feeding. A. americanum is a carrier of multiple diseases, including Ehrlichia chaffeensis, the causative agent of Human Monocyte Ehrlichiosis. This experiment consisted of two main goals: the first was to characterize A. americanum Reprolysin Metalloproteases, and the second to gain a better insight into the relationship between this tick and E. chaffeensis, a pathogen very understudied within the tick vector and has proved problematic for animal model studies. --Page ii.




Arthropod Vector: Controller of Disease Transmission, Volume 2


Book Description

Arthropod Vector: Controller of Disease Transmission, Volume 2: Vector Saliva-Host Pathogen Interactions is built on topics initially raised at a related Keystone Symposium on Arthropod Vectors. Together with the separate, related Volume 1: Controller of Disease Transmission, this work presents a logical sequence of topic development that leads to regulatory considerations for advancing these and related concepts for developing novel control measures. The three themes of symbionts, vector immune defenses and arthropod saliva modulation of the host environment are central to the concept of determinants of vector competence that involves all aspects of vector-borne pathogen development within the arthropod that culminates in the successful transmission to the vertebrate host. These three areas are characterized at the present time by rapid achievement of significant, incremental insights, which advances our understanding for a wide variety of arthropod vector species, and this work is the first to extensively integrate these themes. Provides overviews of host defenses encountered by the blood feeding arthropod vector at the cutaneous interface Addresses how these defenses are modulated by the vector, specific functions of vector saliva components, host response to vector-borne infectious agents and how vector-borne pathogens themselves modulate host defenses Features expertly curated topics to ensure appropriate scope of coverage and aid integration of concepts and content across chapters




Climate, Ticks and Disease


Book Description

This book brings together expert opinions from scientists to consider the evidence for climate change and its impacts on ticks and tick-borne infections. It considers what is meant by 'climate change', how effective climate models are in relation to ecosystems, and provides predictions for changes in climate at global, regional and local scales relevant for ticks and tick-borne infections. It examines changes to tick distribution and the evidence that climate change is responsible. The effect of climate on the physiology and behaviour of ticks is stressed, including potentially critical impacts on the tick microbiome. Given that the notoriety of ticks derives from pathogens they transmit, the book considers whether changes in climate affect vector capacity. Ticks transmit a remarkable range of micro- and macro-parasites many of which are pathogens of humans and domesticated animals. The intimacy between a tick-borne agent and a tick vector means that any impacts of climate on a tick vector will impact tick-borne pathogens. Most obviously, such impacts will be apparent as changes in disease incidence and prevalence. The evidence that climate change is affecting diseases caused by tick-borne pathogens is considered, along with the potential to make robust predictions of future events.




Climate, Ticks and Disease


Book Description

This book is a collection of 77 expert opinions arranged in three sections. Section 1 on "Climate" sets the scene, including predictions of future climate change, how climate change affects ecosystems, and how to model projections of the spatial distribution of ticks and tick-borne infections under different climate change scenarios. Section 2 on "Ticks" focuses on ticks (although tick-borne pathogens creep in) and whether or not changes in climate affect the tick biosphere, from physiology to ecology. Section 3 on "Disease" focuses on the tick-host-pathogen biosphere, ranging from the triangle of tick-host-pathogen molecular interactions to disease ecology in various regions and ecosystems of the world. Each of these three sections ends with a synopsis that aims to give a brief overview of all the expert opinions within the section. The book concludes with Section 4 (Final Synopsis and Future Predictions). This synopsis attempts to summarize evidence provided by the experts of tangible impacts of climate change on ticks and tick-borne infections. In constructing their expert opinions, contributors give their views on what the future might hold. The final synopsis provides a snapshot of their expert thoughts on the future.