Publications

TitleAbstractYear
Filter
PMID
Filter
tick salivary secretion as a source of antihemostatics.ticks are mostly obligatory blood feeding ectoparasites that have an impact on human and animal health. in addition to direct damage due to feeding, some tick species serve as the vectors for the causative agents of several diseases, such as the spirochetes of the genus borrelia causing lyme disease, the virus of tick-borne encephalitis, various rickettsial pathogens or even protozoan parasites like babesia spp. hard ticks are unique among bloodfeeders because of their prolonged feeding period t ...201222564820
a novel rickettsia species detected in vole ticks (ixodes angustus) from western canada.the genomic dna of ixodid ticks from western canada was tested by pcr for the presence of rickettsia. no rickettsiae were detected in ixodes sculptus, whereas 18% of the i. angustus and 42% of the dermacentor andersoni organisms examined were pcr positive for rickettsia. the rickettsiae from each tick species were characterized genetically using multiple genes. rickettsiae within the d. andersoni organisms had sequences at four genes that matched those of r. peacockii. in contrast, the rickettsi ...201324077705
ticks and tick-borne pathogens at the cutaneous interface: host defenses, tick countermeasures, and a suitable environment for pathogen establishment.ticks are unique among hematophagous arthropods by continuous attachment to host skin and blood feeding for days; complexity and diversity of biologically active molecules differentially expressed in saliva of tick species; their ability to modulate the host defenses of pain and itch, hemostasis, inflammation, innate and adaptive immunity, and wound healing; and, the diverse array of infectious agents they transmit. all of these interactions occur at the cutaneous interface in a complex sequence ...201324312085
a nod to disease vectors: mitigation of pathogen sensing by arthropod saliva.arthropod saliva possesses anti-hemostatic, anesthetic, and anti-inflammatory properties that facilitate feeding and, inadvertently, dissemination of pathogens. vector-borne diseases caused by these pathogens affect millions of people each year. many studies address the impact of arthropod salivary proteins on various immunological components. however, whether and how arthropod saliva counters nod-like (nlr) sensing remains elusive. nlrs are innate immune pattern recognition molecules involved i ...201324155744
tick salivary compounds: their role in modulation of host defences and pathogen transmission.ticks require blood meal to complete development and reproduction. multifunctional tick salivary glands play a pivotal role in tick feeding and transmission of pathogens. tick salivary molecules injected into the host modulate host defence responses to the benefit of the feeding ticks. to colonize tick organs, tick-borne microorganisms must overcome several barriers, i.e., tick gut membrane, tick immunity, and moulting. tick-borne pathogens co-evolved with their vectors and hosts and developed m ...201323971008
interaction of the tick immune system with transmitted pathogens.ticks are hematophagous arachnids transmitting a wide variety of pathogens including viruses, bacteria, and protozoans to their vertebrate hosts. the tick vector competence has to be intimately linked to the ability of transmitted pathogens to evade tick defense mechanisms encountered on their route through the tick body comprising midgut, hemolymph, salivary glands or ovaries. tick innate immunity is, like in other invertebrates, based on an orchestrated action of humoral and cellular immune re ...201323875177
isolation of deer tick virus (powassan virus, lineage ii) from ixodes scapularis and detection of antibody in vertebrate hosts sampled in the hudson valley, new york state.deer tick virus, dtv, is a genetically and ecologically distinct lineage of powassan virus (powv) also known as lineage ii powv. human incidence of pow encephalitis has increased in the last 15 years potentially due to the emergence of dtv, particularly in the hudson valley of new york state. we initiated an extensive sampling campaign to determine whether powv was extant throughout the hudson valley in tick vectors and/or vertebrate hosts.201324016533
what is the risk for exposure to vector-borne pathogens in united states national parks?united states national parks attract > 275 million visitors annually and collectively present risk of exposure for staff and visitors to a wide range of arthropod vector species (most notably fleas, mosquitoes, and ticks) and their associated bacterial, protozoan, or viral pathogens. we assessed the current state of knowledge for risk of exposure to vector-borne pathogens in national parks through a review of relevant literature, including internal national park service documents and organismal ...201323540107
pathogens in ticks collected from dogs in berlin/brandenburg, germany.tick-borne diseases are a major health risk for humans and dogs. in addition to collection and analysis of questing ticks, analysis of host-associated ticks for the presence of pathogens is a valuable method to gain insight into transmission patterns of tick-borne diseases.201425441762
bilateral mandibular pyogranulomatous lymphadenitis and pulmonary nodules in a dog with bartonella henselae bacteremia.this report describes a 2-year-old collie dog with pulmonary nodules, visualized by computed tomographic (ct) scan, with evidence of bartonella henselae bacteremia and pyogranulomatous lymphadenitis. clinical signs resolved with antimicrobial therapy.201425320386
population-based passive tick surveillance and detection of expanding foci of blacklegged ticks ixodes scapularis and the lyme disease agent borrelia burgdorferi in ontario, canada.we identified ticks submitted by the public from 2008 through 2012 in ontario, canada, and tested blacklegged ticks ixodes scapularis for borrelia burgdorferi and anaplasma phagocytophilum. among the 18 species of ticks identified, i. scapularis, dermacentor variabilis, ixodes cookei and amblyomma americanum represented 98.1% of the 14,369 ticks submitted. rates of blacklegged tick submission per 100,000 population were highest in ontario's eastern region; d. variabilis in central west and easte ...201425171252
ticks infesting humans in italy and associated pathogens.ticks may transmit a large variety of pathogens, which cause illnesses in animals and humans, commonly referred to as to tick-borne diseases (tbds). the incidence of human tbds in italy is underestimated because of poor surveillance and the scant amount of studies available.201425023709
a 24-48 h fed amblyomma americanum tick saliva immuno-proteome.multiple tick saliva proteins, the majority of which are unknown, confer tick resistance in repeatedly infested animals. the objective of this study was to identify the 24-48 h fed amblyomma americanum tick saliva immuno-proteome. the 24-48 h tick-feeding phase is critical to tick parasitism as it precedes important events in tick biology, blood meal feeding and disease agent transmission. fed male, 24 and 96 h fed female phage display cdna expression libraries were biopanned using rabbit antibo ...201424962723
coinfection of tick cell lines has variable effects on replication of intracellular bacterial and viral pathogens.ticks transmit various human and animal microbial pathogens and may harbour more than one pathogen simultaneously. both viruses and bacteria can trigger, and may subsequently suppress, vertebrate host and arthropod vector anti-microbial responses. microbial coinfection of ticks could lead to an advantage or disadvantage for one or more of the microorganisms. in this preliminary study, cell lines derived from the ticks ixodes scapularis and ixodes ricinus were infected sequentially with 2 arthrop ...201424685441
the tick salivary protein sialostatin l2 inhibits caspase-1-mediated inflammation during anaplasma phagocytophilum infection.saliva from arthropod vectors facilitates blood feeding by altering host inflammation. whether arthropod saliva counters inflammasome signaling, a protein scaffold that regulates the activity of caspase-1 and cleavage of interleukin-1β (il-1β) and il-18 into mature molecules, remains elusive. in this study, we provide evidence that a tick salivary protein, sialostatin l2, inhibits inflammasome formation during pathogen infection. we show that sialostatin l2 targets caspase-1 activity during host ...201424686067
global transcriptional analysis reveals surface remodeling of anaplasma marginale in the tick vector.pathogens dependent upon vectors for transmission to new hosts undergo environment specific changes in gene transcription dependent on whether they are replicating in the vector or the mammalian host. differential gene transcription, especially of potential vaccine candidates, is of interest in anaplasma marginale, the tick-borne causative agent of bovine anaplasmosis.201424751137
laboratory identification of arthropod ectoparasites.the collection, handling, identification, and reporting of ectoparasitic arthropods in clinical and reference diagnostic laboratories are discussed in this review. included are data on ticks, mites, lice, fleas, myiasis-causing flies, and bed bugs. the public health importance of these organisms is briefly discussed. the focus is on the morphological identification and proper handling and reporting of cases involving arthropod ectoparasites, particularly those encountered in the united states. o ...201424396136
surveillance for borrelia burgdorferi in ixodes ticks and small rodents in british columbia.to determine the prevalence of borrelia burgdorferi in british columbian ticks, fieldwork was conducted over a 2-year period. in all, 893 ticks (ixodes pacificus, i. angustus, i. soricis, ixodes spp., and dermacentor andersoni) of different life stages were retrieved from 483 small rodents (peromyscus maniculatus, perognathus parvus, and reithrodontomys megalotis). b. burgdorferi dna was detected in 5 out of 359 tick pools, and 41 out of 483 mice were serologically confirmed to have antibodies a ...201526502354
modulation of host immunity by tick saliva.next generation sequencing and proteomics have helped to comprehensively characterize gene expression in tick salivary glands at both the transcriptome and the proteome level. functional data are, however, lacking. given that tick salivary secretions are critical to the success of the tick transmission lifecycle and, as a consequence, for host colonization by the pathogens they spread, we thoroughly review here the literature on the known interactions between tick saliva (or tick salivary gland ...201526189360
amblyomma americanum as a bridging vector for human infection with francisella tularensis.the γ-proteobacterium francisella tularensis causes seasonal tick-transmitted tularemia outbreaks in natural rabbit hosts and incidental infections in humans in the south-central united states. although dermacentor variabilis is considered a primary vector for f. tularensis, amblyomma americanum is the most abundant tick species in this endemic region. a systematic study of f. tularensis colonization of a. americanum was undertaken to better understand its potential to serve as an overwintering ...201526121137
factors affecting larval tick feeding success: host, density and time.ectoparasites rely on blood-feeding to sustain activity, support development and produce offspring. blood-feeding is also a route for transmission of diverse vector-borne pathogens. the likelihood of successfully feeding is thus an important aspect of ectoparasite population dynamics and pathogen transmission. factors that affect blood-feeding include ectoparasite density, host defenses, and ages of the host and ectoparasite. how these factors interact to affect feeding success is not well under ...201526104393
major emerging vector-borne zoonotic diseases of public health importance in canada.in canada, the emergence of vector-borne diseases may occur via international movement and subsequent establishment of vectors and pathogens, or via northward spread from endemic areas in the usa. re-emergence of endemic vector-borne diseases may occur due to climate-driven changes to their geographic range and ecology. lyme disease, west nile virus (wnv), and other vector-borne diseases were identified as priority emerging non-enteric zoonoses in canada in a prioritization exercise conducted by ...201526954882
conserved amblyomma americanum tick serpin19, an inhibitor of blood clotting factors xa and xia, trypsin and plasmin, has anti-haemostatic functions.tick saliva serine protease inhibitors (serpins) facilitate tick blood meal feeding through inhibition of protease mediators of host defense pathways. we previously identified a highly conserved amblyomma americanum serpin 19 that is characterised by its reactive center loop being 100% conserved in ixodid ticks. in this study, biochemical characterisation reveals that the ubiquitously transcribed a. americanum serpin 19 is an anti-coagulant protein, inhibiting the activity of five of the eight s ...201525957161
passive surveillance for ticks on horses in saskatchewan.passive surveillance of ticks on horses in saskatchewan revealed that the horses were parasitized by 3 species, dermacentor albipictus, d. andersoni, and d. variabilis. the nymphs and adults of d. albipictus occurred on horses earlier in the year than did adults of the 2 other species.201525969582
tick microbiome: the force within.ticks are obligate blood-feeders and serve as vectors of human and livestock pathogens worldwide. defining the tick microbiome and deciphering the interactions between the tick and its symbiotic bacteria in the context of tick development and pathogen transmission will likely reveal new insights and spawn new paradigms to control tick-borne diseases. descriptive observations on the tick microbiome that began almost a century ago serve as forerunners to the gathering momentum to define the tick m ...201525936226
vector potential and population dynamics for amblyomma inornatum.we studied the natural life cycle of amblyomma inornatum and its vector potential in south texas. this tick is distributed throughout south texas and most of central america. a. inornatum represented 1.91% of the ticks collected by carbon dioxide traps during a study of free-living ticks in the tamaulipan biotic province in south texas. the life cycle of a. inornatum in south texas showed a clear seasonal pattern consistent with one generation per year. nymphs emerged in the spring with a peak i ...201525881916
identification of 24h ixodes scapularis immunogenic tick saliva proteins.ixodes scapularis is arguably the most medically important tick species in the united states. this tick transmits 5 of the 14 human tick-borne disease (tbd) agents in the usa: borrelia burgdorferi, anaplasma phagocytophilum, b. miyamotoi, babesia microti, and powassan virus disease. except for the powassan virus disease, i. scapularis-vectored tbd agents require more than 24h post attachment to be transmitted. this study describes identification of 24h immunogenic i. scapularis tick saliva prote ...201525825233
a case of subacute ataxia in the summertime: tick paralysis.tick paralysis is caused by a neurotoxin secreted in the saliva of a gravid female tick, and manifests with ataxia, areflexia, ascending paralysis, bulbar palsy, and ophthalmoparesis. an 84-year-old man presented in june in coastal mississippi with several days of subacute ataxia, bulbar palsy, unilateral weakness, and absent deep tendon reflexes. mri/mra and extensive serum and cerebrospinal fluid investigations were unrevealing. his symptoms progressed over several days, until his nurse discov ...201525794538
tick-borne infections in human and animal population worldwide.the abundance and activity of ectoparasites and its hosts are affected by various abiotic factors, such as climate and other organisms (predators, pathogens and competitors) presenting thus multiples forms of association (obligate to facultative, permanent to intermittent and superficial to subcutaneous) developed during long co-evolving processes. ticks are ectoparasites widespread globally and its eco epidemiology are closely related to the environmental conditions. they are obligatory hematop ...201527047089
sexual differences in the sialomes of the zebra tick, rhipicephalus pulchellus.ticks rely exclusively on vertebrate blood for their survival. during feeding ticks inject into their hosts a sophisticated salivary potion that overcomes host hemostasis and adverse inflammatory responses. these mediators may also enhance pathogen transmission. knowledge of the tick salivary protein repertoire may lead to vaccine targets to disrupt feeding and/or parasite transmission as well as to the discovery of novel pharmacological agents. male saliva may also assist reproduction because m ...201525576852
fluorescent membrane markers elucidate the association of borrelia burgdorferi with tick cell lines.this study aimed to describe the association of borrelia burgdorferi s.s. with ixodid tick cell lines by flow cytometry and fluorescence and confocal microscopy. spirochetes were stained with a fluorescent membrane marker (pkh67 or pkh26), inoculated into 8 different tick cell lines and incubated at 30°c for 24 h. pkh efficiently stained b. burgdorferi without affecting bacterial viability or motility. among the tick cell lines tested, the rhipicephalus appendiculatus cell line ra243 achieved th ...201627332772
dermacentor reticulatus: a vector on the rise.dermacentor reticulatus is a hard tick species with extraordinary biological features. it has a high reproduction rate, a rapid developmental cycle, and is also able to overcome years of unfavourable conditions. dermacentor reticulatus can survive under water for several months and is cold-hardy even compared to other tick species. it has a wide host range: over 60 different wild and domesticated hosts are known for the three active developmental stages. its high adaptiveness gives an edge to th ...201627251148
origin and evolution of rickettsial plasmids.rickettsia species are strictly intracellular bacteria that have undergone a reductive genomic evolution. despite their allopatric lifestyle, almost half of the 26 currently validated rickettsia species have plasmids. in order to study the origin, evolutionary history and putative roles of rickettsial plasmids, we investigated the evolutionary processes that have shaped 20 plasmids belonging to 11 species, using comparative genomics and phylogenetic analysis between rickettsial, microbial and no ...201626866478
antigenic variation in bacterial pathogens.antigenic variation is a strategy used by a broad diversity of microbial pathogens to persist within the mammalian host. whereas viruses make use of a minimal proofreading capacity combined with large amounts of progeny to use random mutation for variant generation, antigenically variant bacteria have evolved mechanisms which use a stable genome, which aids in protecting the fitness of the progeny. here, three well-characterized and highly antigenically variant bacterial pathogens are discussed: ...201626999387
ixodes scapularis tick saliva proteins sequentially secreted every 24 h during blood feeding.ixodes scapularis is the most medically important tick species and transmits five of the 14 reportable human tick borne disease (tbd) agents in the usa. this study describes lc-ms/ms identification of 582 tick- and 83 rabbit proteins in saliva of i. scapularis ticks that fed for 24, 48, 72, 96, and 120 h, as well as engorged but not detached (bd), and spontaneously detached (sd). the 582 tick proteins include proteases (5.7%), protease inhibitors (7.4%), unknown function proteins (22%), immunity ...201626751078
the role of nuclear technologies in the diagnosis and control of livestock diseases--a review.nuclear and nuclear-related technologies have played an important role in animal health, particularly in relation to disease diagnosis and characterization of pathogenic organisms. this review focuses primarily on how and where nuclear technologies, both non-isotopic and isotopic methods, have made their impact in the past and where it might be expected they could have an impact in the future. the review outlines the extensive use of radiation attenuation in attempts to create vaccines for a mul ...201222286376
a 60-year meta-analysis of tick paralysis in the united states: a predictable, preventable, and often misdiagnosed poisoning.tick paralysis (tp) is a neurotoxic poisoning primarily afflicting young girls in endemic regions. recent case series of tp have described increasing misdiagnoses of tp as the guillain-barré syndrome (gbs). a meta-analysis of the scientific literature was conducted using internet search engines to assess the evolving epidemiology of tp. fifty well-documented cases of tp were analyzed over the period 1946-2006. cases were stratified by demographics, clinical manifestations, and outcomes. misdiagn ...201020186584
transmission of pathogens by stomoxys flies (diptera, muscidae): a review.stomoxys flies are mechanical vectors of pathogens present in the blood and skin of their animal hosts, especially livestock, but occasionally humans. in livestock, their direct effects are disturbance, skin lesions, reduction of food intake, stress, blood loss, and a global immunosuppressive effect. they also induce the gathering of animals for mutual protection; meanwhile they favor development of pathogens in the hosts and their transmission. their indirect effect is the mechanical transmissi ...201323985165
unusual bacterial infections and the pleura.rickettsiosis, q fever, tularemia, and anthrax are all bacterial diseases that can affect the pleura. rocky mountain spotted fever (rmsf) and mediterranean spotted fever (msf) are caused by rickettsia rickettsii and rickettsia conorii, respectively. pleural fluid from a patient with msf had a neutrophil-predominant exudate. coxiellaburnetii is the causative agent of q fever. of the two cases described in the literature, one was an exudate with a marked eosinophilia while the other case was a tra ...201222977649
identification of endosymbionts in ticks by broad-range polymerase chain reaction and electrospray ionization mass spectrometry.many organisms, such as insects, filarial nematodes, and ticks, contain heritable bacterial endosymbionts that are often closely related to transmissible tickborne pathogens. these intracellular bacteria are sometimes unique to the host species, presumably due to isolation and genetic drift. we used a polymerase chain reaction/electrospray ionization-mass spectrometry assay designed to detect a wide range of vectorborne microorganisms to characterize endosymbiont genetic signatures from amblyomm ...201222897044
restriction of francisella novicida genetic diversity during infection of the vector midgut.the genetic diversity of pathogens, and interactions between genotypes, can strongly influence pathogen phenotypes such as transmissibility and virulence. for vector-borne pathogens, both mammalian hosts and arthropod vectors may limit pathogen genotypic diversity (number of unique genotypes circulating in an area) by preventing infection or transmission of particular genotypes. mammalian hosts often act as "ecological filters" for pathogen diversity, where novel variants are frequently eliminat ...201425392914
detection of rickettsia rickettsii, rickettsia parkeri, and rickettsia akari in skin biopsy specimens using a multiplex real-time polymerase chain reaction assay.rickettsia rickettsii, rickettsia parkeri, and rickettsia akari are the most common causes of spotted fever group rickettsioses indigenous to the united states. infected patients characteristically present with a maculopapular rash, often accompanied by an inoculation eschar. skin biopsy specimens are often obtained from these lesions for diagnostic evaluation. however, a species-specific diagnosis is achieved infrequently from pathologic specimens because immunohistochemical stains do not diffe ...201424829214
francisella tularensis: no evidence for transovarial transmission in the tularemia tick vectors dermacentor reticulatus and ixodes ricinus.tularemia is a zoonosis caused by the francisella tularensis, a highly infectious gram-negative coccobacillus. due to easy dissemination, multiple routes of infection, high environmental contamination and morbidity and mortality rates, francisella is considered a potential bioterrorism threat and classified as a category a select agent by the cdc. tick bites are among the most prevalent modes of transmission, and ticks have been indicated as a possible reservoir, although their reservoir compete ...201526244842
identification, distribution and population dynamics of francisella-like endosymbiont in haemaphysalis doenitzi (acari: ixodidae).francisella-like endosymbionts (fles) with significant homology to francisella tularensis (γ-proteobacteria) have been characterized in several tick species, whereas knowledge on their distribution and population dynamics in ticks remains meager. hence, in the current study, we identified a novel francisella-like endosymbiont (fles-hd) from the tick haemaphysalis doenitzi and evaluated the putative functions of this symbiont. results indicated that fles-hd had 100% infection rate and a perfect v ...201627731377
superinfection exclusion of the ruminant pathogen anaplasma marginale in its tick vector is dependent on the time between exposures to the strains.the remarkable genetic diversity of vector-borne pathogens allows for the establishment of superinfection in the mammalian host. to have a long-term impact on population strain structure, the introduced strains must also be transmitted by a vector population that has been exposed to the existing primary strain. the sequential exposure of the vector to multiple strains frequently prevents establishment of the second strain, a phenomenon termed superinfection exclusion. as a consequence, superinfe ...201626994084
comparative genomics and transcriptomics of trait-gene association.the order rickettsiales includes important tick-borne pathogens, from rickettsia rickettsii, which causes rocky mountain spotted fever, to anaplasma marginale, the most prevalent vector-borne pathogen of cattle. although most pathogens in this order are transmitted by arthropod vectors, little is known about the microbial determinants of transmission. a. marginale provides unique tools for studying the determinants of transmission, with multiple strain sequences available that display distinct a ...201223181781
discovery of novel rickettsiella spp. in ixodid ticks from western canada.the genomic dna from four species of ixodid ticks in western canada was tested for the presence of rickettsiella by pcr analyses targeting the 16s rrna gene. eighty-eight percent of the ixodes angustus (n = 270), 43% of the i. sculptus (n = 61), and 4% of the i. kingi (n = 93) individuals examined were pcr positive for rickettsiella, whereas there was no evidence for the presence of rickettsiella in dermacentor andersoni (n = 45). three different single-strand conformation polymorphism profiles ...201424334664
the recent evolution of a maternally-inherited endosymbiont of ticks led to the emergence of the q fever pathogen, coxiella burnetii.q fever is a highly infectious disease with a worldwide distribution. its causative agent, the intracellular bacterium coxiella burnetii, infects a variety of vertebrate species, including humans. its evolutionary origin remains almost entirely unknown and uncertainty persists regarding the identity and lifestyle of its ancestors. a few tick species were recently found to harbor maternally-inherited coxiella-like organisms engaged in symbiotic interactions, but their relationships to the q fever ...201525978383
anaplasma marginale actively modulates vacuolar maturation during intracellular infection of its tick vector, dermacentor andersoni.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 of the tick blood m ...201627235428
dermatologic emergencies. 200516301696
effects of bartonella spp. on flea feeding and reproductive performance.numerous pathogens are transmitted from one host to another by hematophagous insect vectors. the interactions between a vector-borne organism and its vector vary in many ways, most of which are yet to be explored and identified. these interactions may play a role in the dynamics of the infection cycle. one way to evaluate these interactions is by studying the effects of the tested organism on the vector. in this study, we tested the effects of infection with bartonella species on fitness-related ...201323542614
antiviral responses of arthropod vectors: an update on recent advances.arthropod vectors, such as mosquitoes, ticks, biting midges and sand flies, transmit many viruses that can cause outbreaks of disease in humans and animals around the world. arthropod vector species are invading new areas due to globalisation and environmental changes, and contact between exotic animal species, humans and arthropod vectors is increasing, bringing with it the regular emergence of new arboviruses. for future strategies to control arbovirus transmission, it is important to improve ...201425674592
the salivary secretome of the biting midge, culicoides sonorensis.culicoides biting midges (diptera: ceratopogonidae) are hematophagous insects with over 1400 species distributed throughout the world. many of these species are of particular agricultural importance as primary vectors of bluetongue and schmallenberg viruses, yet little is known about culicoides genomics and proteomics. detailed studies of members from other blood-feeding dipteran families, including those of mosquito (culicidae) and black fly (simuliidae), have shown that protein components with ...201424949243
consequences of in vitro host shift for st. louis encephalitis virus.understanding the potential for host range shifts and expansions of rna viruses is critical to predicting the evolutionary and epidemiological paths of these pathogens. as arthropod-borne viruses (arboviruses) experience frequent spillover from their amplification cycles and are generalists by nature, they are likely to experience a relatively high frequency of success in a range of host environments. despite this, the potential for host expansion, the genetic correlates of adaptation to novel e ...201424643879
intertwined arbovirus transmission activity: reassessing the transmission cycle paradigm.arboviruses are emerging/reemerging infectious agents worldwide. the factors within this scenario include vector and host population fluctuations, climatic changes, anthropogenic activities that disturb ecosystems, an increase in international flights, human mobility, and genetic mutations that allow spill-over phenomenon. arboviruses are maintained by biologic transmission among vectors and hosts. sometimes this biological transmission is specific and includes one vector and host species such a ...201323335900
arthropod-borne disease in canada: a clinician's perspective from the 'cold zone'.arthropod-borne diseases do not occur commonly in canada. nevertheless, canadians run the risk of contracting certain infections within the country during arthropod season, as well as when travelling abroad. therefore, it is important that clinicians are aware of the possible occurrence of arthropod-borne diseases, and consider them in their differential diagnoses. the present review is divided into two sections: arthropod-borne diseases or disease agents documented in canada, and imported arthr ...020177520
is transfusion-transmitted dengue fever a potential public health threat?dengue is an arboviruses due to single-stranded enveloped ribonucleic acid viruses, named dengue viruses (denv), that include four serotypes and are mainly transmitted via the bite of mosquitoes of the genus aedes (a. aegypti and a. albopictus). the distribution of the disease was historically limited to intertropical areas; however, during the last thirty years, the perimeter of the disease extended considerably and temperate areas are now at risk of outbreaks. the present global burden of deng ...025964876
west nile virus adaptation to ixodid tick cells is associated with phenotypic trade-offs in primary hosts.west nile virus (wnv; flaviviridae, flavivirus) is the most geographically widespread arthropod-borne virus (arbovirus) in the world and is found in multiple ecologically distinct settings. despite the likelihood of frequent exposure to novel hosts, studies evaluating the capacity and correlates of host range expansions or shifts of wnv and other arboviruses are generally lacking. we utilized experimental evolution of wnv in an amblyomma americanum tick cell line to model an invertebrate host sh ...201525863877
hybridization in natural sympatric populations of dermacentor ticks in northwestern north america.hybridization in ticks has been described in a handful of species and mostly as a result of laboratory experiments. we used 148 aflp loci to describe putative hybridization events between d. andersoni and d. variabilis in sympatric populations from northwestern north america. recently, d. variabilis has expanded its range westward into the natural range of d. andersoni. using a sample of 235 d. andersoni and 62 d. variabilis, we identified 31 individuals as putative hybrids: four f2 individuals ...201323531531
powassan virus infection: case series and literature review from a single institution.powassan virus is a flavivirus related to eastern hemisphere's tick-borne encephalitis viruses. it can cause a rare but potentially life-threatening disease including encephalitis.201223111001
tick-borne encephalitis virus subtypes emerged through rapid vector switches rather than gradual evolution.tick-borne encephalitis is the most important human arthropod-borne virus disease in europe and russia, with an annual incidence of about 13 thousand people. tick-borne encephalitis virus (tbev) is distributed in the natural foci of forest and taiga zones of eurasia, from the pacific to the atlantic coast. currently, there are three mutually exclusive hypotheses about the origin and distribution of tbev subtypes, although they are based on the same assumption of gradual evolution. recently, we h ...201425540692
endogenous tick viruses and modulation of tick-borne pathogen growth.ticks transmit a wide range of viral, bacterial and protozoan pathogens, many of which can establish persistent infections of lifelong duration in the vector tick and in some cases are transmitted transovarially to the next generation. in addition many ixodid and argasid tick cell lines and, by inference the parent ticks from which they were derived, harbor endogenous viruses (etv) of which almost nothing is known. in general, low level persistent infections with viral pathogens (arboviruses) ar ...201323875176
detection and identification of putative bacterial endosymbionts and endogenous viruses in tick cell lines.as well as being vectors of many viral, bacterial, and protozoan pathogens of medical and veterinary importance, ticks harbour a variety of microorganisms which are not known to be pathogenic for vertebrate hosts. continuous cell lines established from ixodid and argasid ticks could be infected with such endosymbiotic bacteria and endogenous viruses, but to date very few cell lines have been examined for their presence. dna and rna extracted from over 50 tick cell lines deposited in the roslin w ...201222743047
update on tick-borne rickettsioses around the world: a geographic approach.tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus rickettsia. these zoonoses are among the oldest known vector-borne diseases. however, in the past 25 years, the scope and importance of the recognized tick-associated rickettsial pathogens have increased dramatically, making this complex of diseases an ideal paradigm for the understanding of emerging and reemerging infections. several species of tick-borne rickettsiae that wer ...024092850
characterization of haemaphysalis flava (acari: ixodidae) from qingling subspecies of giant panda (ailuropoda melanoleuca qinlingensis) in qinling mountains (central china) by morphology and molecular markers.tick is one of important ectoparasites capable of causing direct damage to their hosts and also acts as vectors of relevant infectious agents. in the present study, the taxa of 10 ticks, collected from qinling giant pandas (ailuropoda melanoleuca qinlingensis) in qinling mountains of china in april 2010, were determined using morphology and molecular markers (nucleotide its2 rdna and mitochondrial 16s). microscopic observation demonstrated that the morphological features of these ticks were simi ...201323894541
anaplasma species of veterinary importance in japan.anaplasma species of the family anaplasmataceae, order rickettsiales are tick-borne organisms that can cause disease in animals and humans. in japan, all recognized species of anaplasma (except for anaplasma ovis) and a potentially novel anaplasma sp. closely related to anaplasma phagocytophilum have been reported. most of these detected tick-borne pathogens are believed to be lowly pathogenic in animals in japan although the zoonotic a. phagocytophilum has recently been reported to cause clinic ...201627956767
identification of novel coxiella burnetii genotypes from ethiopian ticks.coxiella burnetii, the etiologic agent of q fever, is a highly infectious zoonotic bacterium. genetic information about the strains of this worldwide distributed agent circulating on the african continent is limited. the aim of the present study was the genetic characterization of c. burnetii dna samples detected in ticks collected from ethiopian cattle and their comparison with other genotypes found previously in other parts of the world.201425423309
challenges posed by tick-borne rickettsiae: eco-epidemiology and public health implications.rickettsiae are obligately intracellular bacteria that are transmitted to vertebrates by a variety of arthropod vectors, primarily by fleas and ticks. once transmitted or experimentally inoculated into susceptible mammals, some rickettsiae may cause febrile illness of different morbidity and mortality, and which can manifest with different types of exhanthems in humans. however, most rickettsiae circulate in diverse sylvatic or peridomestic reservoirs without having obvious impacts on their vert ...201525954738
tick-box for 3'-end formation of mitochondrial transcripts in ixodida, basal chelicerates and drosophila.according to the trna punctuation model, the mitochondrial genome (mtdna) of mammals and arthropods is transcribed as large polycistronic precursors that are maturated by endonucleolytic cleavage at trna borders and rna polyadenylation. starting from the newly sequenced mtdna of ixodes ricinus and using a combination of mitogenomics and transcriptional analyses, we found that in all currently-sequenced tick lineages (prostriata, metastriata and argasidae) the 3'-end of the polyadenylated nad1 an ...201223077630
the sialotranscriptome of antricola delacruzi female ticks is compatible with non-hematophagous behavior and an alternative source of food.the hosts for antricola delacruzi ticks are insectivorous, cave-dwelling bats on which only larvae are found. the mouthparts of nymphal and adult a. delacruzi are compatible with scavenging feeding because the hypostome is small and toothless. how a single blood meal of a larva provides energy for several molts as well as for oviposition by females is not known. adults of a. delacruzi possibly feed upon an unknown food source in bat guano, a substrate on which nymphal and adult stages are always ...201222306723
experimental infection of horses with rickettsia rickettsii.rickettsia rickettsii is vectored by ticks, and some vertebrate hosts can be sources of infection to ticks during bacteremic periods. in brazil, the main vector for r. rickettsii is the tick amblyomma sculptum, a member of the a. cajennense complex. horses, in turn, are one of the major hosts for a. sculptum. in this study, horses experimentally infected with r. rickettsii were assessed for clinical changes and their capability to transmit the infection to a. sculptum ticks.201627624315
genetic identification of rickettsial isolates from fatal cases of brazilian spotted fever and comparison with rickettsia rickettsii isolates from the american continents.fifteen bacterial isolates from spotted fever group rickettsiosis in brazil were genetically identified as rickettsia rickettsii. in a phylogenetic analysis with other r. rickettsii isolates from genbank, the central/south american isolates showed low polymorphism and formed a clade distinct from two north american clades, with the north american clades having greater in-branch polymorphism.201425078908
growth of ehrlichia canis, the causative agent of canine monocytic ehrlichiosis, in vector and non-vector ixodid tick cell lines.canine monocytic ehrlichiosis is caused by ehrlichia canis, a small gram-negative coccoid bacterium that infects circulating monocytes. the disease is transmitted by the brown dog tick rhipicephalus sanguineus s.l. and is acknowledged as an important infectious disease of dogs and other members of the family canidae worldwide. e. canis is routinely cultured in vitro in the canine monocyte-macrophage cell line dh82 and in non-vector ixodes scapularis tick cell lines, but not in cells derived from ...201626837859
propagation of the israeli vaccine strain of anaplasma centrale in tick cell lines.anaplasma centrale has been used in cattle as a live blood vaccine against the more pathogenic anaplasma marginale for over 100 years. while a. marginale can be propagated in vitro in tick cell lines, facilitating studies on antigen production, immunisation and vector-pathogen interaction, to date there has been no in vitro culture system for a. centrale. in the present study, 25 cell lines derived from 13 ixodid tick species were inoculated with the israeli vaccine strain of a. centrale and mon ...201526210950
partial characterization of a novel anti-inflammatory protein from salivary gland extract of hyalomma anatolicum anatolicum 77acari: ixodidae) ticks.hyalomma anatolicum anatolicum ticks transmit theileria annulata, causative agent of tropical theileriosis to cattle and buffaloes causing a major economic loss in terms of production and mortality in tropical countries. ticks have evolved several immune evading strategies to circumvent hosts' rejection and achieve engorgement. successful feeding of ticks relies on a pharmacy of chemicals located in their complex salivary glands and secreted saliva. these chemicals in saliva could inhibit host i ...201527065646
importance of ticks and their chemical and immunological control in livestock.the medical and economic importance of ticks has long been recognized due to their ability to transmit diseases to humans and animals. ticks cause great economic losses to livestock, and adversely affect livestock hosts in several ways. loss of blood is a direct effect of ticks acting as potential vector for haemo-protozoa and helminth parasites. blood sucking by large numbers of ticks causes reduction in live weight and anemia among domestic animals, while their bites also reduce the quality of ...017048307
arthropod surveillance programs: basic components, strategies, and analysis.effective entomological surveillance planning stresses a careful consideration of methodology, trapping technologies, and analysis techniques. herein, the basic principles and technological components of arthropod surveillance plans are described, as promoted in the symposium "advancements in arthropod monitoring technology, techniques, and analysis" presented at the 58th annual meeting of the entomological society of america in san diego, ca. interdisciplinary examples of arthropod monitoring f ...026543242
molecular detection of rickettsia species in ticks collected from the southwestern provinces of the republic of korea.rickettsiae constitute a group of arthropod-borne, gram-negative, obligate intracellular bacteria that are the causative agents of diseases ranging from mild to life threatening that impact on medical and veterinary health worldwide.201728069059
neural control of salivary glands in ixodid ticks.studies of tick salivary glands (sgs) and their components have produced a number of interesting discoveries over the last four decades. however, the precise neural and physiological mechanisms controlling sg secretion remain enigmatic. major studies of sg control have identified and characterized many pharmacological and biological compounds that activate salivary secretion, including dopamine (da), octopamine, γ-aminobutyric acid (gaba), ergot alkaloids, pilocarpine (pc), and their pharmacolog ...201122119563
feeding period required by amblyomma aureolatum ticks for transmission of rickettsia rickettsii to vertebrate hosts.rocky mountain spotted fever is endemic to the são paulo metropolitan area, brazil, where the etiologic agent, rickettsia rickettsii, is transmitted to humans by adult amblyomma aureolatum ticks. we determined the minimal feeding period required by a. aureolatum nymphs and adults to transmit r. rickettsii to guinea pigs. unfed nymphs and unfed adult ticks had to be attached to the host for >10 hours to transmit r. rickettsii. in contrast, fed ticks needed a minimum of 10 minutes of attachment to ...025148391
comparative evaluation of infected and noninfected amblyomma triste ticks with rickettsia parkeri, the agent of an emerging rickettsiosis in the new world.the distribution of rickettsia parkeri in south america has been associated with amblyomma triste ticks. the present study evaluated under laboratory conditions two colonies of a. triste: one started from engorged females that were naturally infected by r. parkeri (designated as infected group); the other started from noninfected females (designated as control group). both colonies were reared in parallel for five consecutive generations. tick-naïve domestic rabbits were used for feeding of each ...201323936795
high prevalence of "candidatus rickettsia andeanae" and apparent exclusion of rickettsia parkeri in adult amblyomma maculatum (acari: ixodidae) from kansas and oklahoma.amblyomma maculatum (the gulf coast tick), an aggressive, human-biting, nearctic and neotropical tick, is the principal vector of rickettsia parkeri in the united states. this pathogenic spotted fever group rickettsia species has been identified in 8-52% of questing adult gulf coast ticks in the southeastern united states. to our knowledge, r. parkeri has not been reported previously from adult specimens of a. maculatum collected in kansas or oklahoma. a total of 216 adult a. maculatum ticks wer ...201525773931
the sialotranscriptome of amblyomma triste, amblyomma parvum and amblyomma cajennense ticks, uncovered by 454-based rna-seq.tick salivary constituents antagonize inflammatory, immune and hemostatic host responses, favoring tick blood feeding and the establishment of tick-borne pathogens in hosts during hematophagy. amblyomma triste, a. cajennense and a. parvum ticks are very important in veterinary and human health because they are vectors of the etiological agents for several diseases. insights into the tick salivary components involved in blood feeding are essential to understanding vector-pathogen-host interaction ...201425201527
molecular detection and genotyping of coxiella-like endosymbionts in ticks that infest horses in south korea.members of the genus coxiella can be transmitted from ticks to humans during contact with animals; coxiella may thus spread from the infected horses or ticks to humans. in this study, the presence of coxiella burnetii and coxiella-like endosymbionts (cle) in ticks found on infested horses was determined using pcr and genotyping. a total of 213 ticks were randomly collected from 51 horses (4-5 ticks per horse) raised on jeju island, korea, between 2009 and 2013. all ticks were morphologically ide ...201627792764
histoarchitecture of the ovary of rhipicephalus (boophilus) annulatus during pre- and postengorgement period.the present communication describes the detailed day wise study of histological changes of the ovary of rhipicephalus (boophilus) annulatus in the postengorgement period together with the systematic classification of their oocytes. the ovary of r. (b.) annulatus is panoistic type with an asynchronous development of oocytes. all the stages (ii, iii, iv, and v) of oocytes except stage i were similar to r. (b.) microplus. the stage i oocytes showed basophilia, which was not reported earlier in othe ...201525664337
sensitivity to permethrin in a dermacentor reticulatus population from eastern poland in laboratory study.the action of chemical compounds on the palaearctic tick d. reticulatus (fabricius) (acari: amblyomminae) has been poorly investigated so far. therefore, the effects of application of permethrin on engorged d. reticulatus females have been assessed, and the survival rate for the different developmental stages of the tick species in its non-parasitic phase of the life cycle was determined upon application of the pyrethroid.201424405550
ixodes pacificus ticks maintain embryogenesis and egg hatching after antibiotic treatment of rickettsia endosymbiont.rickettsia is a genus of intracellular bacteria that causes a variety of diseases in humans and other mammals and associates with a diverse group of arthropods. although rickettsia appears to be common in ticks, most rickettsia-tick relationships remain generally uncharacterized. the most intimate of these associations is rickettsia species phylotype g021, a maternally and transstadially transmitted endosymbiont that resides in 100% of i. pacificus in california. we investigated the effects of t ...201425105893
de novo ixodes ricinus salivary gland transcriptome analysis using two next-generation sequencing methodologies.tick salivary gland (sg) proteins possess powerful pharmacologic properties that facilitate tick feeding and pathogen transmission. for the first time, sg transcriptomes of ixodes ricinus, an important disease vector for humans and animals, were analyzed using next-generation sequencing. sgs were collected from different tick life stages fed on various animal species, including cofeeding of nymphs and adults on the same host. four cdna samples were sequenced, discriminating tick sg transcriptome ...201323964076
immunoregulation of bovine macrophages by factors in the salivary glands of rhipicephalus microplus.alternative strategies are required to control the southern cattle tick, rhipicephalus microplus, due to evolving resistance to commercially available acaricides. this invasive ectoparasite is a vector of economically important diseases of cattle such as bovine babesiosis and anaplasmosis. an understanding of the biological intricacies underlying vector-host-pathogen interactions is required to innovate sustainable tick management strategies that can ultimately mitigate the impact of animal and ...201222333193
saliva from nymph and adult females of haemaphysalis longicornis: a proteomic study.haemaphysalis longicornis is a major vector of theileria spp., anaplasma phagocytophilum, babesia spp. and coxiella burnetti in east asian countries. all life stages of ixodid ticks have a destructive pool-feeding style in which they create a pool-feeding site by lacerating host tissue and secreting a variety of biologically active compounds that allows the tick to evade host responses, enabling the uptake of a blood meal. the identification and functional characterization of tick saliva protein ...201526104117
saliva of rhipicephalus (boophilus) microplus (acari: ixodidae) inhibits classical and alternative complement pathways.rhipicephalus (boophilus) microplus is the main ectoparasite affecting livestock worldwide. for a successful parasitism, ticks need to evade several immune responses of their hosts, including the activation of the complement system. in spite of the importance of r. microplus, previous work only identified one salivary molecule that blocks the complement system. the current study describes complement inhibitory activities induced by r. microplus salivary components and mechanisms elicited by puta ...201627515662
molecular methods routinely used to detect coxiella burnetii in ticks cross-react with coxiella-like bacteria.q fever is a widespread zoonotic disease caused by coxiella burnetii. ticks may act as vectors, and many epidemiological studies aim to assess c. burnetii prevalence in ticks. because ticks may also be infected with coxiella-like bacteria, screening tools that differentiate between c. burnetii and coxiella-like bacteria are essential.201526609691
comparative genome sequencing of rickettsia rickettsii strains that differ in virulence.rickettsia rickettsii is an obligate intracellular pathogen that is the causative agent of rocky mountain spotted fever. strains of r. rickettsii differ dramatically in virulence. in a guinea pig model of infection, the severity of disease as assessed by fever response varies from the most virulent, sheila smith, to iowa, which causes no fever. to identify potential determinants of virulence in r. rickettsii, the genomes of two additional strains were sequenced for comparison to known sequences ...201525644009
immunosuppressive effects of amblyomma cajennense tick saliva on murine bone marrow-derived dendritic cells.dendritic cells (dcs) are professional antigen-presenting cells with vital roles in the activation of host immunity. ticks are bloodsucking arthropods that secrete bioactive compounds with immunomodulatory properties via their saliva. it is known that some tick species modulate the biology of dcs with different intensities; however, studies on amblyomma cajennense, the cayenne tick, have not yet been performed, although this species is considered one of the most capable of modulating immune resp ...201525586117
tick-borne lymphadenopathy-like condition in an african woman in kenya.a 30-year-old african woman in kenya succumbed to severe swollen regional lymph nodes, development of painful boils and ulcer formation and rashes at specific tick-biting sites together with an intermittent fever and headache following repeated tick bites of rhipicephalus pulchellus. she later developed nuchal lymphadenopathy-like condition and an eschar with edematous margins at bitten sites. a sustained high fever and fatigue then followed. she became well after treatment with antibiotics and ...024497868
an insight into the microbiome of the amblyomma maculatum (acari: ixodidae).the aim of this study was to survey the bacterial diversity of amblyomma maculatum koch, 1844, and characterize its infection with rickettsia parkeri. pyrosequencing of the bacterial 16s rrna was used to determine the total bacterial population in a. maculatum. pyrosequencing analysis identified rickettsia in a. maculatum midguts, salivary glands, and saliva, which indicates successful trafficking in the arthropod vector. the identity of rickettsia spp. was determined based on sequencing the ric ...024605461
insight into the salivary gland transcriptome of lygus lineolaris (palisot de beauvois).the tarnished plant bug (tpb), lygus lineolaris (palisot de beauvois) is a polyphagous, phytophagous insect that has emerged as a major pest of cotton, alfalfa, fruits, and vegetable crops in the eastern united states and canada. using its piercing-sucking mouthparts, tpb employs a "lacerate and flush" feeding strategy in which saliva injected into plant tissue degrades cell wall components and lyses cells whose contents are subsequently imbibed by the tpb. it is known that a major component of ...201626789269
high prevalence of rickettsia africae variants in amblyomma variegatum ticks from domestic mammals in rural western kenya: implications for human health.tick-borne spotted fever group (sfg) rickettsioses are emerging human diseases caused by obligate intracellular gram-negative bacteria of the genus rickettsia. despite being important causes of systemic febrile illnesses in travelers returning from sub-saharan africa, little is known about the reservoir hosts of these pathogens. we conducted surveys for rickettsiae in domestic animals and ticks in a rural setting in western kenya. of the 100 serum specimens tested from each species of domestic r ...025325312
identification of rhipicephalus microplus genes that modulate the infection rate of the rickettsia anaplasma marginale.arthropod vectors transmit a diversity of animal and human pathogens, ranging from rna viruses to protozoal parasites. chemotherapeutic control of pathogens has classically focused either on insecticides that kill the vector itself or antimicrobials for infected patients. the limitation of the former is that it targets both infected and uninfected vectors and selects for resistant populations while the latter requires prompt and accurate diagnosis. an alternative strategy is to target vector mol ...201424608654
molecular cloning and sequence analysis of the cdnas encoding toxin-like peptides from the venom glands of tarantula grammostola rosea.tarantula venom glands produce a large variety of bioactive peptides. here we present the identification of venom components obtained by sequencing clones isolated from a cdna library prepared from the venom glands of the chilean common tarantula, grammostola rosea. the cdna sequences of about 1500 clones out of 4000 clones were analyzed after selection using several criteria. forty-eight novel toxin-like peptides (gtx1 to gtx7, and gtx-tctp and gtx-crisp) were predicted from the nucleotide sequ ...201222500178
Displaying items 401 - 500 of 562