Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| case report: a case of colorado tick fever acquired in southwestern saskatchewan. | colorado tick fever virus is transmitted by dermacentor andersoni ticks. in canada, these ticks are found in the southern regions of british columbia (rocky mountains) and alberta, as well as southwestern saskatchewan. colorado tick fever should be clinically suspected in patients presenting with a biphasic febrile illness and leukopenia following tick exposure in the appropriate geographic area. | 2018 | 29363458 |
| a retrospective cohort study of tick paralysis in british columbia. | tick paralysis is a frequently overlooked severe disease characterized by bilateral ascending flaccid paralysis caused by a neurotoxin produced by feeding ticks. we aimed to characterize suspected tick paralysis cases documented at the bc centre for disease control (bccdc) in british columbia (bc) from 1993 to 2016 and reviewed prevention, diagnosis, and treatment considerations. | 2017 | 29083955 |
| laboratory colonization stabilizes the naturally dynamic microbiome composition of field collected dermacentor andersoni ticks. | nearly a quarter of emerging infectious diseases identified in the last century are arthropod-borne. although ticks and insects can carry pathogenic microorganisms, non-pathogenic microbes make up the majority of their microbial communities. the majority of tick microbiome research has had a focus on discovery and description; very few studies have analyzed the ecological context and functional responses of the bacterial microbiome of ticks. the goal of this analysis was to characterize the stab ... | 2017 | 28978338 |
| the immunomodulatory protein rh36 is relating to blood-feeding success and oviposition in hard ticks. | an immunomodulatory protein designated rh36 was identified in the tick rhipicephalus haemaphysaloides. the cdna sequence of rh36 has 844bp and encodes a deduced protein with a predicted molecular weight of 24kda. bioinformatics analysis indicated that rh36 presented a degree of similarity of 34.36% with the immunomodulatory protein p36 from the tick dermacentor andersoni. the recombinant rh36 (rrh36) expressed in sf9 insect cells suppressed the t-lymphocyte mitogen-driven in vitro proliferation ... | 2017 | 28449954 |
| 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. | 2017 | 28069059 |
| 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 ... | 2016 | 27792764 |
| 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. | 2016 | 27624315 |
| 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 ... | 2016 | 26837859 |
| 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 ... | 2016 | 27235428 |
| 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 ... | 2016 | 27956767 |
| 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 ... | 2016 | 27332772 |
| 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 ... | 2016 | 27251148 |
| 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 ... | 2016 | 26866478 |
| 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: ... | 2016 | 26999387 |
| 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 ... | 2016 | 26751078 |
| 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 ... | 2016 | 27731377 |
| 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 ... | 2016 | 26994084 |
| embryo development and morphology of the rocky mountain wood tick (acari: ixodidae). | dermacentor andersoni stiles embryogenesis was observed using fluorescent and scanning electron microscopy for eggs held under laboratory conditions (25°c and at 93% relative humidity). early embryonic cell divisions appeared to be synchronous and holoblastic, giving rise to a uniform blastoderm surrounding the yolk. the cells of the blastoderm became concentrated on one side of the embryo, forming the segmented germ band. distinct opisthosomal and prosomal segment morphologies, which are charac ... | 2016 | 26668102 |
| effect of rickettsia rickettsii (rickettsiales: rickettsiaceae) infection on the biological parameters and survival of its tick vector-dermacentor variabilis (acari: ixodidae). | rocky mountain spotted fever, caused by rickettsia rickettsii, is a potentially fatal tick-borne disease spread from north america to argentina. the major vectors of r. rickettsii in the united states are dermacentor andersoni stiles and dermacentor variabilis (say). it is generally believed that vector ticks serve as major reservoirs of r. rickettsii in nature; however, the ability of ticks to support the indefinite perpetuation of r. rickettsii has been challenged by reports of deleterious eff ... | 2016 | 26494822 |
| new records of ticks (acari: ixodidae) from dogs, cats, humans, and some wild vertebrates in alaska: invasion potential. | during 2010-2016, tick specimens were solicited from veterinarians, biologists, and members of the public in alaska. eight species of ticks were recorded from domestic dogs. some ticks were collected from dogs with recent travel histories to other countries or other u.s. states, which appears to explain records of ticks not native to alaska such as amblyomma americanum (l.) (lone star tick), ixodes scapularis (say) (blacklegged tick), and ixodes ricinus (l.). however, we recorded dermacentor var ... | 2016 | 27524823 |
| the bacterial microbiome of dermacentor andersoni ticks influences pathogen susceptibility. | ticks are of medical importance owing to their ability to transmit pathogens to humans and animals. the rocky mountain wood tick, dermacentor andersoni, is a vector of a number of pathogens, including anaplasma marginale, which is the most widespread tick-borne pathogen of livestock. although ticks host pathogenic bacteria, they also harbor bacterial endosymbionts that have a role in tick physiology, survival, as well as pathogen acquisition and transmission. the goal of this study was to charac ... | 2016 | 26882265 |
| can subclinical infestation by paralyzing dermacentor andersoni (acari: ixodidae) induce immunity to tick paralysis in sheep? | cattle and sheep can develop immunity to paralysis caused by dermacentor andersoni stiles; however, this has been reported only in animals that were initially challenged with a high dose of ticks and exhibited clear symptoms of paralysis. paralysis in sheep occurs in a dose-dependent fashion, with no paralysis occurring in sheep exposed to <0.2 ticks per kilogram sheep weight, and 100% paralysis in sheep exposed to >0.8 ticks per kilogram. this experiment was conducted to determine if sheep expo ... | 2016 | 26802171 |
| 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 ... | 2016 | 27515662 |
| arsenophonus nasoniae and rickettsiae infection of ixodes ricinus due to parasitic wasp ixodiphagus hookeri. | arsenophonus nasoniae, a male-killing endosymbiont of chalcid wasps, was recently detected in several hard tick species. following the hypothesis that its presence in ticks may not be linked to the direct occurrence of bacteria in tick's organs, we identified a. nasoniae in wasps emerging from parasitised nymphs. we confirmed that 28.1% of ixodiphagus hookeri wasps parasitizing ixodes ricinus ticks were infected by a. nasoniae. moreover, in examined i. ricinus nymphs, a. nasoniae was detected on ... | 2016 | 26901622 |
| 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 ... | 2016 | 26789269 |
| evasins: therapeutic potential of a new family of chemokine-binding proteins from ticks. | blood-sucking parasites, such as ticks, remain attached to their hosts for relatively long periods of time in order to obtain their blood meal without eliciting an immune response. one mechanism used to avoid rejection is the inhibition of the recruitment of immune cells, which can be achieved by a class of chemokine-binding proteins (ckbps) known as evasins. we have identified three distinct evasins produced by the salivary glands of the common brown dog tick, rhipicephalus sanguineus. they dis ... | 2016 | 27375615 |
| anaplasma marginale: diversity, virulence, and vaccine landscape through a genomics approach. | in order to understand the genetic diversity of a. marginale, several efforts have been made around the world. this rickettsia affects a significant number of ruminants, causing bovine anaplasmosis, so the interest in its virulence and how it is transmitted have drawn interest not only from a molecular point of view but also, recently, some genomics research have been performed to elucidate genes and proteins with potential as antigens. unfortunately, so far, we still do not have a recombinant a ... | 2016 | 27610385 |
| tick holocyclotoxins trigger host paralysis by presynaptic inhibition. | ticks are important vectors of pathogens and secreted neurotoxins with approximately 69 out of 692 tick species having the ability to induce severe toxicoses in their hosts. the australian paralysis tick (ixodes holocyclus) is known to be one of the most virulent tick species producing a flaccid paralysis and fatalities caused by a family of neurotoxins known as holocyclotoxins (hts). the paralysis mechanism of these toxins is temperature dependent and is thought to involve inhibition of acetylc ... | 2016 | 27389875 |
| antiplasmodial activity is an ancient and conserved feature of tick defensins. | ancestral sequence reconstruction has been widely used to test evolution-based hypotheses. the genome of the european tick vector, ixodes ricinus, encodes for defensin peptides with diverse antimicrobial activities against distantly related pathogens. these pathogens include fungi, gram-negative, and gram-positive bacteria, i.e., a wide antimicrobial spectrum. ticks do not transmit these pathogens, suggesting that these defensins may act against a wide range of microbes encountered by ticks duri ... | 2016 | 27822206 |
| borrelia miyamotoi disease: neither lyme disease nor relapsing fever. | borrelia miyamotoi disease (bmd) is a newly recognized borreliosis globally transmitted by ticks of the ixodes persulcatus species complex. once considered to be a tick symbiont with no public health implications, b miyamotoi is increasingly recognized as the agent of a nonspecific febrile illness often misdiagnosed as acute lyme disease without rash, or as ehrlichiosis. the frequency of its diagnosis in the northeastern united states is similar to that of human granulocytic ehrlichiosis. a diag ... | 2015 | 26593262 |
| tissue distribution of the ehrlichia muris-like agent in a tick vector. | human pathogens transmitted by ticks undergo complex life cycles alternating between the arthropod vector and a mammalian host. while the latter has been investigated to a greater extent, examination of the biological interactions between microbes and the ticks that carry them presents an equally important opportunity for disruption of the disease cycle. in this study, we used in situ hybridization to demonstrate infection by the ehrlichia muris-like organism, a newly recognized human pathogen, ... | 2015 | 25781930 |
| the characterization and manipulation of the bacterial microbiome of the rocky mountain wood tick, dermacentor andersoni. | in north america, ticks are the most economically impactful vectors of human and animal pathogens. the rocky mountain wood tick, dermacentor andersoni (acari: ixodidae), transmits rickettsia rickettsii and anaplasma marginale to humans and cattle, respectively. in recent years, studies have shown that symbiotic organisms are involved in a number of biochemical and physiological functions. characterizing the bacterial microbiome of d. andersoni is a pivotal step towards understanding symbiont-hos ... | 2015 | 26653035 |
| subdominant outer membrane antigens in anaplasma marginale: conservation, antigenicity, and protective capacity using recombinant protein. | anaplasma marginale is a tick-borne rickettsial pathogen of cattle with a worldwide distribution. currently a safe and efficacious vaccine is unavailable. outer membrane protein (omp) extracts or a defined surface protein complex reproducibly induce protective immunity. however, there are several knowledge gaps limiting progress in vaccine development. first, are these omps conserved among the diversity of a. marginale strains circulating in endemic regions? second, are the most highly conserved ... | 2015 | 26079491 |
| targeted knockout of the rickettsia rickettsii ompa surface antigen does not diminish virulence in a mammalian model system. | strains of rickettsia rickettsii, the causative agent of rocky mountain spotted fever (rmsf), differ dramatically in virulence despite >99% genetic homology. spotted fever group (sfg) rickettsiae produce two immunodominant outer membrane proteins, rickettsial ompa (rompa) and rompb, which are conserved throughout the sfg and thought to be fundamental to pathogenesis. rompa is present in all virulent strains of r. rickettsii but is not produced in the only documented avirulent strain, iowa, due t ... | 2015 | 25827414 |
| association of anaplasma marginale strain superinfection with infection prevalence within tropical regions. | strain superinfection occurs when a second strain infects a host already infected with and having mounted an immune response to a primary strain. the incidence of superinfection with anaplasma marginale, a tick-borne rickettsial pathogen of domestic and wild ruminants, has been shown to be higher in tropical versus temperate regions. this has been attributed to the higher prevalence of infection, with consequent immunity against primary strains and thus greater selective pressure for superinfect ... | 2015 | 25793966 |
| reduced infectivity in cattle for an outer membrane protein mutant of anaplasma marginale. | anaplasma marginale is the causative agent of anaplasmosis in cattle. transposon mutagenesis of this pathogen using the himar1 system resulted in the isolation of an omp10 operon insertional mutant referred to as the omp10::himar1 mutant. the work presented here evaluated if this mutant had morphological and/or growth rate defects compared to wild-type a. marginale. results showed that the morphology, developmental cycle, and growth in tick and mammalian cell cultures are similar for the mutant ... | 2015 | 25595772 |
| rocky mountain spotted fever characterization and comparison to similar illnesses in a highly endemic area-arizona, 2002-2011. | rocky mountain spotted fever (rmsf) has emerged as a significant cause of morbidity and mortality since 2002 on tribal lands in arizona. the explosive nature of this outbreak and the recognition of an unexpected tick vector, rhipicephalus sanguineus, prompted an investigation to characterize rmsf in this unique setting and compare rmsf cases to similar illnesses. | 2015 | 25697743 |
| identification and mechanistic analysis of a novel tick-derived inhibitor of thrombin. | a group of peptides from the salivary gland of the tick hyalomma marginatum rufipes, a vector of crimean congo hemorrhagic fever show weak similarity to the madanins, a group of thrombin-inhibitory peptides from a second tick species, haemaphysalis longicornis. we have evaluated the anti-serine protease activity of one of these h. marginatum peptides that has been given the name hyalomin-1. hyalomin-1 was found to be a selective inhibitor of thrombin, blocking coagulation of plasma and inhibitin ... | 2015 | 26244557 |
| 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. | 2015 | 26609691 |
| 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 ... | 2015 | 25644009 |
| 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 ... | 2015 | 25586117 |
| 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 ... | 2015 | 25773931 |
| 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 ... | 2015 | 26104117 |
| distribution and habitat of ixodes pacificus (acari: ixodidae) and prevalence of borrelia burgdorferi in utah. | knowledge about the distribution and abundance of the western black-legged tick, ixodes pacificus cooley and kohls, in utah is limited. recent concerns over tick-borne diseases in utah, primarily lyme disease, have reinvigorated the need to understand the distribution and habitats favored by this tick species. we surveyed 157 sites throughout utah to examine the distribution, abundance, and habitat of i. pacificus. in total, 343 adult ticks were collected from 2011 to 2013. specifically, 119 i. ... | 2015 | 26336263 |
| 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 ... | 2015 | 26244842 |
| 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 ... | 2015 | 26502354 |
| 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 ... | 2015 | 26189360 |
| 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 ... | 2015 | 26121137 |
| 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 ... | 2015 | 26104393 |
| 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 ... | 2015 | 26954882 |
| 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 ... | 2015 | 25957161 |
| 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. | 2015 | 25969582 |
| 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 ... | 2015 | 25936226 |
| 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 ... | 2015 | 25881916 |
| 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 ... | 2015 | 25825233 |
| 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 ... | 2015 | 25794538 |
| 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 ... | 2015 | 27047089 |
| 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 ... | 2015 | 25576852 |
| 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 ... | 2015 | 25863877 |
| 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 ... | 2015 | 25978383 |
| 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 ... | 2015 | 26210950 |
| 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 ... | 2015 | 27065646 |
| 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 ... | 2015 | 25954738 |
| 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 ... | 2015 | 25664337 |
| 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. | 2014 | 24405550 |
| 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 ... | 2014 | 25105893 |
| 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. | 2014 | 25078908 |
| 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 ... | 2014 | 25674592 |
| 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 ... | 2014 | 24949243 |
| 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 ... | 2014 | 24643879 |
| 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. | 2014 | 25423309 |
| 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 ... | 2014 | 25540692 |
| 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. | 2014 | 25441762 |
| 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. | 2014 | 25320386 |
| 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 ... | 2014 | 25171252 |
| 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. | 2014 | 25023709 |
| 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 ... | 2014 | 24962723 |
| 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 ... | 2014 | 24685441 |
| 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 ... | 2014 | 24686067 |
| 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. | 2014 | 24751137 |
| 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 ... | 2014 | 24396136 |
| 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 ... | 2014 | 24334664 |
| 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 ... | 2014 | 25392914 |
| 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 ... | 2014 | 24829214 |
| influence of temperature on oviposition by dermacentor andersoni (acari: ixodidae). | the effects of temperature on oviposition by dermacentor andersoni (stiles) was examined using replete females ranging in weight from 30 to 1,198 mg. survivorship was >96% during the preoviposition periods and declined during oviposition period. egg production peaked earlier and at greater levels as temperature increased. longevity, preoviposition period, and oviposition period declined as temperature increased. replete weight had minor effects on measures of time, but smaller females tended to ... | 2014 | 25276920 |
| comparative off-host survival of larval rocky mountain wood ticks (dermacentor andersoni) collected from ecologically distinct field populations. | dermacentor andersoni (ixodida: ixodidae) stiles, also known as the rocky mountain wood tick (rmwt), is found throughout the western united states and transmits pathogens of importance to human and animal health. the distributions and activity patterns of rmwts are shaped by regional climatic variation. however, it is unknown if responses to climatic variation differ across the tick's geographical range. the objective of this narrow study was to test the hypothesis that the responses of rmwts to ... | 2014 | 24665893 |
| mutation scanning-based identification of larval and nymphal ticks (acari: ixodidae) from richardson's ground squirrels (spermophilus richardsonii). | the objective of this study was to identify the tick species parasitizing richardson's ground squirrels (spermophilus richardsonii) in southern saskatchewan (canada). morphological examination of the adult ticks revealed the presence of three tick species, ixodes sculptus, ixodes kingi and dermacentor andersoni. however, given the difficulties in identifying some of the larval and nymphal (immature) ticks using this approach, pcr-based single-strand conformation polymorphism (sscp) and dna seque ... | 2014 | 24075866 |
| proteomics informed by transcriptomics identifies novel secreted proteins in dermacentor andersoni saliva. | dermacentor andersoni, known as the rocky mountain wood tick, is found in the western united states and transmits pathogens that cause diseases of veterinary and public health importance including rocky mountain spotted fever, tularemia, colorado tick fever and bovine anaplasmosis. tick saliva is known to modulate both innate and acquired immune responses, enabling ticks to feed for several days without detection. during feeding ticks subvert host defences such as hemostasis and inflammation, wh ... | 2014 | 25110293 |
| occurrence and county-level distribution of ticks (acari: ixodoidea) in nebraska using passive surveillance. | a 100 yr (1911-2011) examination of tick submissions was compiled from the u.s. national tick collection and three state databases to determine tick species occurrence in nebraska sixteen tick species were identified including amblyomma americanum (l.), dermacentor variabilis (say), dermacentor albipictus (packard), dermacentor andersoni stiles, haemaphysalis leporispalustris (packard), rhipicephalus sanguineus (latreille), and otobius megrini (dughs). amblyomma maculatum koch and ixodes scapula ... | 2014 | 24724283 |
| salivary gland degeneration and ovarian development in the rocky mountain wood tick, dermacentor andersoni stiles (acari: ixodidae). i. post-engorgement events. | it is well known that female ixodid ticks undergo salivary gland degeneration and the greater part of ovarian development following engorgement. the process has been particularly well studied in amblyomma hebraeum, including the hormonal control of these processes. the purpose of this study, and the second one in this series, is to compare the processes in dermacentor andersoni with those of a. hebraeum. a major difference between the two species is that virgin female d. andersoni feed to a much ... | 2014 | 24973274 |
| salivary gland degeneration and ovary development in the rocky mountain wood tick, dermacentor andersoni stiles (acari: ixodidae). ii. determination of the 'critical weight'. | the feeding cycle of female ixodid ticks is divided into preparatory, slow, and rapid feeding phases. when a female amblyomma hebraeum is removed from the host after achieving a minimum size of about 10-13× the unfed weight, various physiological and behavioural changes occur: (a) haemolymph ecdysteroid concentration rises dramatically, (b) the tick does not reattach to the host when given the opportunity, (c) its salivary glands degenerate within about 4 days (if mated) or 8 days (if virgin), a ... | 2014 | 24865927 |
| infection with colorado tick fever virus among humans and ticks in a national park and forest, wyoming, 2010. | colorado tick fever (ctf) is an underreported tick-borne viral disease occurring in the western united states. ctf illness includes fever, headache, and severe myalgia lasting for weeks. wyoming has one of the highest ctf incidence rates with approximately 30% of infected persons reporting tick exposure in a wyoming national park or forest before symptom onset. we assessed ctf virus infections among humans and dermacentor andersoni ticks in grand teton national park (grte) and bridger-teton nati ... | 2014 | 25229706 |
| are ticks venomous animals? | as an ecological adaptation venoms have evolved independently in several species of metazoa. as haematophagous arthropods ticks are mainly considered as ectoparasites due to directly feeding on the skin of animal hosts. ticks are of major importance since they serve as vectors for several diseases affecting humans and livestock animals. ticks are rarely considered as venomous animals despite that tick saliva contains several protein families present in venomous taxa and that many ixodida genera ... | 2014 | 25006341 |
| 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 ... | 2014 | 25201527 |
| cultivation of rickettsia amblyommii in tick cells, prevalence in florida lone star ticks (amblyomma americanum). | rickettsia amblyommii is a bacterium in the spotted fever group of organisms associated with the lone star tick (lst), amblyomma americanum. the lst is the most commonly reported tick to parasitize humans in the southeastern us. within this geographic region, there have been suspected cases of rocky mountain spotted fever (rmsf) where the causative agent, r. rickettsii, was not identified in the local tick population. in these areas, patients with clinical signs of rmsf had low or no detectable ... | 2014 | 24927809 |
| 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 ... | 2014 | 24608654 |
| community-based control of the brown dog tick in a region with high rates of rocky mountain spotted fever, 2012-2013. | rocky mountain spotted fever (rmsf) transmitted by the brown dog tick (rhipicephalus sanguineus sensu lato) has emerged as a significant public health risk on american indian reservations in eastern arizona. during 2003-2012, more than 250 rmsf cases and 19 deaths were documented among arizona's american indian population. the high case fatality rate makes community-level interventions aimed at rapid and sustained reduction of ticks urgent. beginning in 2012, a two year pilot integrated tick pre ... | 2014 | 25479289 |
| anaplasma marginale superinfection attributable to pathogen strains with distinct genomic backgrounds. | strain superinfection occurs when a second pathogen strain infects a host already infected with a primary strain. the selective pressures that drive strain divergence, which underlies superinfection, and allow penetration of a new strain into a host population are critical knowledge gaps relevant to shifts in infectious disease epidemiology. in regions of endemicity with a high prevalence of infection, broad population immunity develops against anaplasma marginale, a highly antigenically variant ... | 2014 | 25287920 |
| inadequacy of igm antibody tests for diagnosis of rocky mountain spotted fever. | among 13 suspected rocky mountain spotted fever (rmsf) cases identified through an enhanced surveillance program in tennessee, antibodies to rickettsia rickettsii were detected in 10 (77%) patients using a standard indirect immunofluorescent antibody (ifa) assay. immunoglobulin m (igm) antibodies were observed for 6 of 13 patients (46%) without a corresponding development of igg, and for 3 of 10 patients (30%) at least 1 year post-onset. however, recent infection with a spotted fever group ricke ... | 2014 | 25092818 |
| phylogeography of rickettsia rickettsii genotypes associated with fatal rocky mountain spotted fever. | rocky mountain spotted fever (rmsf), a tick-borne zoonosis caused by rickettsia rickettsii, is among the deadliest of all infectious diseases. to identify the distribution of various genotypes of r. rickettsii associated with fatal rmsf, we applied molecular typing methods to samples of dna extracted from formalin-fixed, paraffin-embedded tissue specimens obtained at autopsy from 103 case-patients from seven countries who died of rmsf. complete sequences of one or more intergenic regions were am ... | 2014 | 24957541 |