Publications

TitleAbstractYear
Filter
PMID
Filter
coinfection by ixodes tick-borne pathogens: ecological, epidemiological, and clinical consequences.ixodes ticks maintain a large and diverse array of human pathogens in the enzootic cycle, including borrelia burgdorferi and babesia microti. despite the poor ecological fitness of b. microti, babesiosis has recently emerged in areas endemic for lyme disease. studies in ticks, reservoir hosts, and humans indicate that coinfection with b. burgdorferi and b. microti is common, promotes transmission and emergence of b. microti in the enzootic cycle, and causes greater disease severity and duration ...201526613664
a 35-year-old man with a positive lyme test result from a private laboratory. 201526323702
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
survey of ixodes pacificus ticks in california reveals a diversity of microorganisms and a novel and widespread anaplasmataceae species.ixodes pacificus ticks can harbor a wide range of human and animal pathogens. to survey the prevalence of tick-borne known and putative pathogens, we tested 982 individual adult and nymphal i. pacificus ticks collected throughout california between 2007 and 2009 using a broad-range pcr and electrospray ionization mass spectrometry (pcr/esi-ms) assay designed to detect a wide range of tick-borne microorganisms. overall, 1.4% of the ticks were found to be infected with borrelia burgdorferi, 2.0% w ...201526375033
disease risk & landscape attributes of tick-borne borrelia pathogens in the san francisco bay area, california.habitat heterogeneity influences pathogen ecology by affecting vector abundance and the reservoir host communities. we investigated spatial patterns of disease risk for two human pathogens in the borrelia genus-b. burgdorferi and b. miyamotoi-that are transmitted by the western black-legged tick, ixodes pacificus. we collected ticks (349 nymphs, 273 adults) at 20 sites in the san francisco bay area, california, usa. tick abundance, pathogen prevalence and density of infected nymphs varied widely ...201526288371
human granulocytic anaplasmosis in the united states from 2008 to 2012: a summary of national surveillance data.human granulocytic anaplasmosis is an acute, febrile illness transmitted by the ticks ixodes scapularis and ixodes pacificus in the united states. we present a summary of passive surveillance data for cases of anaplasmosis with onset during 2008-2012. the overall reported incidence rate (ir) was 6.3 cases per million person-years. cases were reported from 38 states and from new york city, with the highest incidence in minnesota (ir = 97), wisconsin (ir = 79), and rhode island (ir = 51). thirty-s ...201525870428
the increasing risk of lyme disease in canada.there is an increasing risk of lyme disease in canada due to range expansion of the tick vector, ixodes scapularis. the objectives of this article are to i) raise public awareness with the help of veterinarians on the emerging and expanding risk of lyme disease across canada, ii) review the key clinical features of lyme disease in dogs, and iii) provide recommendations for veterinarians on the management of lyme disease in dogs.201526130829
tick bites in the lyme light. 201526175558
seroprevalence of equine granulocytic anaplasmosis and lyme borreliosis in canada as determined by a point-of-care enzyme-linked immunosorbent assay (elisa).equine granulocytic anaplasmosis (ega) and lyme borreliosis (lb) are an emerging concern in canada. we estimated the seroprevalence of ega and equine lb by testing 376 convenience serum samples from 3 provinces using a point-of-care snap(®) 4dx(®) elisa (idexx laboratories, westbrook, maine, usa), and investigated the agreement between the point-of-care elisa and laboratory-based serologic tests. the estimated seroprevalence for ega was 0.53% overall (0.49% in saskatchewan, 0.71% in manitoba), w ...201526028677
chronic lyme disease: misconceptions and challenges for patient management.lyme disease, infection with the tick-borne spirochete borrelia burgdorferi, causes both specific and nonspecific symptoms. in untreated chronic infection, specific manifestations such as a relapsing large-joint oligoarthritis can persist for years, yet subside with appropriate antimicrobial therapy. nervous system involvement occurs in 10%-15% of untreated patients and typically involves lymphocytic meningitis, cranial neuritis, and/or mononeuritis multiplex; in some rare cases, patients have p ...201526028977
lyme disease bacterium does not affect attraction to rodent odour in the tick vector.vector-borne pathogens experience a conflict of interest when the arthropod vector chooses a vertebrate host that is incompetent for pathogen transmission. the qualitative manipulation hypothesis suggests that vector-borne pathogens can resolve this conflict in their favour by manipulating the host choice behaviour of the arthropod vector.201525928557
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
potential role of masting by introduced bamboos in deer mice (peromyscus maniculatus) population irruptions holds public health consequences.we hypothesized that the ongoing naturalization of frost/shade tolerant asian bamboos in north america could cause environmental consequences involving introduced bamboos, native rodents and ultimately humans. more specifically, we asked whether the eventual masting by an abundant leptomorphic ("running") bamboo within pacific northwest coniferous forests could produce a temporary surfeit of food capable of driving a population irruption of a common native seed predator, the deer mouse (peromysc ...201525898267
evaluation of the importance of vlse antigenic variation for the enzootic cycle of borrelia burgdorferi.efficient acquisition and transmission of borrelia burgdorferi by the tick vector, and the ability to persistently infect both vector and host, are important elements for the life cycle of the lyme disease pathogen. previous work has provided strong evidence implicating the significance of the vls locus for b. burgdorferi persistence. however, studies involving vls mutant clones have thus far only utilized in vitro-grown or host-adapted spirochetes and laboratory strains of mice. additionally, t ...201525893989
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
borrelia burgdorferi not confirmed in human-biting amblyomma americanum ticks from the southeastern united states.the predominant human-biting tick throughout the southeastern united states is amblyomma americanum. its ability to transmit pathogens causing lyme disease-like illnesses is a subject of ongoing controversy. results of previous testing by the department of defense human tick test kit program and other laboratories indicated that it is highly unlikely that a. americanum transmits any pathogen that causes lyme disease. in contrast, a recent publication by clark and colleagues (k. l. clark, b. leyd ...201525788545
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
anaphylaxis to the carbohydrate side chain alpha-gal.in 2007, the monoclonal antibody cetuximab caused severe hypersensitivity reactions during the first infusion in a region of the southeastern united states. investigation of pretreatment sera established that they contained immunoglobulin (ig) e against the oligosaccharide galactose-alpha-1,3-galactose (alpha-gal), which is present on the fab of cetuximab. alpha-gal is a blood group substance of nonprimate mammals. these ige antibodies are also associated with delayed anaphylaxis to red meat (ie ...201525841549
borrelia burgdorferi sensu lato spirochetes in wild birds in northwestern california: associations with ecological factors, bird behavior and tick infestation.although borrelia burgdorferi sensu lato (s.l.) are found in a great diversity of vertebrates, most studies in north america have focused on the role of mammals as spirochete reservoir hosts. we investigated the roles of birds as hosts for subadult ixodes pacificus ticks and potential reservoirs of the lyme disease spirochete b. burgdorferi sensu stricto (s.s.) in northwestern california. overall, 623 birds representing 53 species yielded 284 i. pacificus larvae and nymphs. we used generalized l ...201525714376
borrelia miyamotoi infection in nature and in humans.borrelia miyamotoi is a relapsing fever borrelia group spirochete that is transmitted by the same hard-bodied (ixodid) tick species that transmit the agents of lyme disease. it was discovered in 1994 in ixodes persulcatus ticks in japan. b. miyamotoi species phylogenetically cluster with the relapsing fever group spirochetes, which usually are transmitted by soft-bodied (argasid) ticks or lice. b. miyamotoi infects at least six ixodes tick species in north america and eurasia that transmit lyme ...201525700888
immunization with a recombinant subunit ospa vaccine markedly impacts the rate of newly acquired borrelia burgdorferi infections in client-owned dogs living in a coastal community in maine, usa.in north america, borrelia burgdorferi is the causative bacterial agent of canine lyme borreliosis and is transmitted following prolonged attachment and feeding of vector ticks, ixodes scapularis or ixodes pacificus. its prevention is predicated upon tick-avoidance, effective on-animal tick control and effective immunization strategies. the purpose of this study is to characterize dogs that are newly seropositive for borrelia burgdorferi infection in relation to compliant use of a recombinant os ...201525890386
γδ t cells and dendritic cells in refractory lyme arthritis.lyme disease is a multisystem infection transmitted by tick vectors with an incidence of up to 300,000 individuals/yr in the united states. the primary treatments are oral or i.v. antibiotics. despite treatment, some individuals do not recover and have prolonged symptoms affecting multiple organs, including the nervous system and connective tissues. inflammatory arthritis is a common symptom associated with lyme pathology. in the past decades, γδ t cells have emerged as candidates that contribut ...201525605869
comparison of tick feeding success and vector competence for borrelia burgdorferi among immature ixodes scapularis (ixodida: ixodidae) of both southern and northern clades.northern and southern ixodes scapularis say populations differ greatly in density, host utilization, and especially questing behavior of the immatures. haplotypes of i. scapularis in north america can be divided into two major clades-the all american clade (haplotypes a through j) and the southern clade (m through o). this genetic variation may affect feeding success and vector competence. this study compared feeding success of larval i. scapularis measured by time-to-drop-off and subsequent tra ...201526336283
nested coevolutionary networks shape the ecological relationships of ticks, hosts, and the lyme disease bacteria of the borrelia burgdorferi (s.l.) complex.the bacteria of the borrelia burgdorferi (s.l.) (bbg) complex constitute a group of tick-transmitted pathogens that are linked to many vertebrate and tick species. the ecological relationships between the pathogens, the ticks and the vertebrate carriers have not been analysed. the aim of this study was to quantitatively analyse these interactions by creating a network based on a large dataset of associations. specifically, we examined the relative positions of partners in the network, the phylog ...201627662832
molecular evidence of bartonella species in ixodid ticks and domestic animals in palestine.ticks play an important role in disease transmission as vectors for human and animal pathogens, including the gram-negative pathogen bartonella. here, we evaluated the presence of bartonella in ixodid ticks and domestic animals from palestine. we tested 633 partly engorged ticks and 139 blood samples from domestic animals (dogs, sheep and camels) for bartonella using its-pcr. bartonella dna was detected in 3.9% of the tested ticks. none of the ticks collected from sheep and goats were positive f ...201627540374
novel borrelia species detected in echidna ticks, bothriocroton concolor, in australia.to date, little has been documented about microorganisms harboured within australian native ticks or their pathogenic potential. recently, a borrelia sp. related to the relapsing fever (rf) group was identified in a single tick removed from a wild echidna (tachyglossus aculeatus). the present study investigated the presence of borrelia in 97 bothriocroton concolor ticks parasitizing echidnas in queensland, new south wales, and victoria, australia, using nested pcr with borrelia-specific primers ...201627301754
identification of new drug candidates against borrelia burgdorferi using high-throughput screening.lyme disease is the most common zoonotic bacterial disease in north america. it is estimated that >300,000 cases per annum are reported in usa alone. a total of 10%-20% of patients who have been treated with antibiotic therapy report the recrudescence of symptoms, such as muscle and joint pain, psychosocial and cognitive difficulties, and generalized fatigue. this condition is referred to as posttreatment lyme disease syndrome. while there is no evidence for the presence of viable infectious org ...201627103785
factors associated with anaplasma spp. seroprevalence among dogs in the united states.dogs in the united states are hosts to a diverse range of ticks and tick-borne pathogens, including a. phagocytophilum, an important emerging canine and human pathogen. previously, a companion animal parasite council (capc)-sponsored workshop proposed factors purported to be associated with the infection risk for tick-transmitted pathogens in dogs in the united states, including climate conditions, socioeconomic characteristics, local topography, and vector distribution.201627004557
update on canine and feline blood donor screening for blood-borne pathogens.an update on the 2005 american college of veterinary internal medicine (acvim) consensus statement on blood donor infectious disease screening was presented at the 2015 acvim forum in indianapolis, indiana, followed by panel and audience discussion. the updated consensus statement is presented below. the consensus statement aims to provide guidance on appropriate blood-borne pathogen testing for canine and feline blood donors in north america.201626806261
lyme disease risk in southern california: abiotic and environmental drivers of ixodes pacificus (acari: ixodidae) density and infection prevalence with borrelia burgdorferi.tick-borne diseases, particularly lyme disease, are emerging across the northern hemisphere. in order to manage emerging diseases and predict where emergence will likely occur, it is necessary to understand the factors influencing the distribution, abundance and infection prevalence of vector species. in north america, lyme disease is the most common vector-borne disease and is transmitted by blacklegged ticks. this study aimed to explore the abiotic and environmental drivers of density and infe ...201728057067
tick surveillance for relapsing fever spirochete borrelia miyamotoi in hokkaido, japan.during 2012-2013, a total of 4325 host-seeking adult ticks belonging to the genus ixodes were collected from various localities of hokkaido, the northernmost island of japan. tick lysates were subjected to real-time pcr assay to detect borrelial infection. the assay was designed for specific detection of the relapsing fever spirochete borrelia miyamotoi and for unspecific detection of lyme disease-related spirochetes. overall prevalence of b. miyamotoi was 2% (71/3532) in ixodes persulcatus, 4.3 ...201425111141
an o-methyltransferase is required for infection of tick cells by anaplasma phagocytophilum.anaplasma phagocytophilum, the causative agent of human granulocytic anaplasmosis (hga), is an obligately intracellular α-proteobacterium that is transmitted by ixodes spp ticks. however, the pathogen is not transovarially transmitted between tick generations and therefore needs to survive in both a mammalian host and the arthropod vector to complete its life cycle. to adapt to different environments, pathogens rely on differential gene expression as well as the modification of proteins and othe ...201526544981
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
bartonella henselae infection in a family experiencing neurological and neurocognitive abnormalities after woodlouse hunter spider bites.bartonella species comprise a group of zoonotic pathogens that are usually acquired by vector transmission or by animal bites or scratches.201323587343
the wolbachia wo bacteriophage proteome in the aedes albopictus c/wstr1 cell line: evidence for lytic activity?wolbachia pipientis (rickettsiales), an obligate intracellular alphaproteobacterium in insects, manipulates host reproduction to maximize invasion of uninfected insect populations. modification of host population structure has potential applications for control of pest species, particularly if wolbachia can be maintained, manipulated, and genetically engineered in vitro. although wolbachia maintains an obligate mutualism with genome stability in nematodes, arthropods can be co-infected with dist ...201526427709
winding paths to simplicity: genome evolution in facultative insect symbionts.symbiosis between organisms is an important driving force in evolution. among the diverse relationships described, extensive progress has been made in insect-bacteria symbiosis, which improved our understanding of the genome evolution in host-associated bacteria. particularly, investigations on several obligate mutualists have pushed the limits of what we know about the minimal genomes for sustaining cellular life. to bridge the gap between those obligate symbionts with extremely reduced genomes ...201627519426
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
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
analysis of the immune-related transcriptome of a lophotrochozoan model, the marine annelid platynereis dumerilii.the marine annelid platynereis dumerilii (polychaeta, nereididae) has been recognized as a slow-evolving lophotrochozoan that attracts increasing attention as a valuable model for evolutionary and developmental research. here, we analyzed its immune-related transcriptome. for targeted identification of immune-induced genes we injected bacterial lipopolysaccharide, a commonly used elicitor of innate immune responses, and applied the suppression subtractive hybridization technique that selectively ...200717617895
climate change and infectious diseases in north america: the road ahead.global climate change is inevitable--the combustion of fossil fuels has resulted in a buildup of greenhouse gases within the atmosphere, causing unprecedented changes to the earth's climate. the fourth assessment report of the intergovernmental panel on climate change suggests that north america will experience marked changes in weather patterns in coming decades, including warmer temperatures and increased rainfall, summertime droughts and extreme weather events (e.g., tornadoes and hurricanes) ...018332386
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
experimental infections of wild birds with west nile virus.avian models of west nile virus (wnv) disease have become pivotal in the study of infection pathogenesis and transmission, despite the intrinsic constraints that represents this type of experimental research that needs to be conducted in biosecurity level 3 (bsl3) facilities. this review summarizes the main achievements of wnv experimental research carried out in wild birds, highlighting advantages and limitations of this model. viral and host factors that determine the infection outcome are ana ...201424531334
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
on the potential roles of ticks and migrating birds in the ecology of west nile virus.mosquitoes are the primary vectors of west nile virus (wnv). ticks have, however, been suggested to be potential reservoirs of wnv. in order to investigate their role in the spread of the virus, ticks, which had been collected from birds migrating northwards from africa to europe, were analyzed for the potential presence of wnv-rna.201424455105
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
evidence for interspecific interactions in the ectoparasite infracommunity of a wild mammal.co-infection with multiple parasite species is commonly observed in nature and interspecific interactions are likely to occur in parasite infracommunities. such interactions may affect the distribution of parasites among hosts but also the response of infracommunities to perturbations. however, the response of infracommunities to perturbations has not been well studied experimentally for ectoparasite communities of small mammal hosts.201626830510
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
multiplex sybr® green-real time pcr (qpcr) assay for the detection and differentiation of bartonella henselae and bartonella clarridgeiae in cats.a novel sybr® green-real time polymerase chain reaction (qpcr) was developed to detect two bartonella species, b. henselae and b. clarridgeiae, directly from blood samples. the test was used in blood samples obtained from cats living in animal shelters in southern brazil. results were compared with those obtained by conventional pcr targeting bartonella spp. among the 47 samples analyzed, eight were positive using the conventional pcr and 12 were positive using qpcr. importantly, the new qpcr de ...024626408
anaplasma phagocytophilum--a widespread multi-host pathogen with highly adaptive strategies.the bacterium anaplasma phagocytophilum has for decades been known to cause the disease tick-borne fever (tbf) in domestic ruminants in ixodes ricinus-infested areas in northern europe. in recent years, the bacterium has been found associated with ixodes-tick species more or less worldwide on the northern hemisphere. a. phagocytophilum has a broad host range and may cause severe disease in several mammalian species, including humans. however, the clinical symptoms vary from subclinical to fatal ...201323885337
molecular epidemiology of the emerging zoonosis agent anaplasma phagocytophilum (foggie, 1949) in dogs and ixodid ticks in brazil.anaplasma phagocytophilum is an emerging pathogen of humans, dogs and other animals, and it is transmitted by ixodid ticks. the objective of the current study was a) detect a. phagocytophilum in dogs and ixodid ticks using real-time polymerase chain reaction (qpcr); and b) determine important variables associated to host, environment and potential tick vectors that are related to the presence of a. phagocytophilum in dogs domiciled in rio de janeiro, brazil.201324330631
biomarkers for exposure to sand flies bites as tools to aid control of leishmaniasis.intense research efforts so far have not been sufficient to reduce leishmaniasis burden worldwide. this disease is transmitted by bites of infected sand flies, which inject saliva in the host skin in an attempt to obtain a blood meal. sand fly saliva has an array of proteins with diverse pharmacological properties that modulates the host homeostatic and immune responses. some of these proteins are also immunogenic and can induce both cellular and humoral immune responses. recently, the use of sa ...201222661974
platelet aggregation inhibitors from hematophagous animals.salivary glands from blood-sucking animals (e.g., mosquitoes, bugs, sand flies, fleas, ticks, leeches, hookworms, bats) are a rich source of bioactive molecules that counteract hemostasis in a redundant and synergistic manner. this review discusses recent progress in the identification of salivary inhibitors of platelet aggregation, their molecular characterization, and detailed mechanism of action. diversity of inhibitors is remarkable, with distinct families of proteins characterized as apyras ...200920035779
anopheles salivary gland proteomes from major malaria vectors.antibody responses against anopheles salivary proteins can indicate individual exposure to bites of malaria vectors. the extent to which these salivary proteins are species-specific is not entirely resolved. thus, a better knowledge of the diversity among salivary protein repertoires from various malaria vector species is necessary to select relevant genus-, subgenus- and/or species-specific salivary antigens. such antigens could be used for quantitative (mosquito density) and qualitative (mosqu ...201223148599
unique strains of anaplasma phagocytophilum segregate among diverse questing and non-questing ixodes tick species in the western united states.the emerging tick-borne pathogen anaplasma phagocytophilum infects humans, domestic animals, and wildlife throughout the holarctic. in the western us, the ecology of a. phagocytophilum is particularly complex, with multiple pathogen strains, tick vectors, and reservoir hosts. a recent phylogenetic analysis of a. phagocytophilum strains isolated from various small mammal hosts in california documented distinct clustering of woodrat strains separate from sciurid (chipmunk and squirrel) strains. he ...201323994335
ticks and rickettsiae from wildlife in belize, central america.the agents of spotted fevers in latin america are rickettsia rickettsii, r. parkeri, rickettsia sp. strain atlantic rainforest, and r. massiliae. in continental central america, r. rickettsii remains the only known pathogenic tick-borne rickettsia. in the present study, ticks were collected from wild mammals in natural areas of belize. besides providing new data of ticks from belize, we investigated rickettsial infection in some of these ticks. our results provide ticks harboring rickettsial age ...201626831147
host blood meal-dependent growth ensures transovarial transmission and transstadial passage of rickettsia sp. phylotype g021 in the western black-legged tick (ixodes pacificus).in this study, we explored the growth dynamics of rickettsia sp. phylotype g021 during transovarial transmission and transstadial passage by ixodes pacificus using real-time quantitative pcr. four parental engorged i. pacificus females were allowed to complete their developmental stages until the f2-generation eggs yielded unfed larvae. all eggs, larvae, nymphs, and adults tested through 2 generations were found to be infected with phylotype g021. hence, we conclude that the efficiency of transo ...201323876278
evaluation of different nested pcrs for detection of anaplasma phagocytophilum in ruminants and ticks.anaplasma phagocytophilum is a causative agent of granulocytic anaplasmosis in mammals, which has a broad geographical distribution and a high degree of clinical diversity. currently, numerous pcr assays have been developed and used for the detection of a. phagocytophilum in various specimens. however, their performance varies. the aim of this study was to evaluate the performance of five nested pcr assays by detection of 363 ruminant and tick samples, and to select the most appropriate methods ...201626911835
molecular survey and characterization of a novel anaplasma species closely related to anaplasma capra in ticks, northwestern china.anaplasma spp. are tick-transmitted bacteria that infect a wide variety of wild and domestic animals. these pathogens exhibit a high degree of biological diversity, broad geographical distribution, and represent a serious threat to veterinary and public health worldwide.201627884197
unique strain of borrelia miyamotoi in ixodes pacificus ticks, california, usa. 201627479523
the rickettsia endosymbiont of ixodes pacificus contains all the genes of de novo folate biosynthesis.ticks and other arthropods often are hosts to nutrient providing bacterial endosymbionts, which contribute to their host's fitness by supplying nutrients such as vitamins and amino acids. it has been detected, in our lab, that ixodes pacificus is host to rickettsia species phylotype g021. this endosymbiont is predominantly present, and 100% maternally transmitted in i. pacificus. to study roles of phylotype g021 in i. pacificus, bioinformatic and molecular approaches were carried out. mummer gen ...201526650541
isolation and propagation of a spiroplasma sp. from slovakian ixodes ricinus ticks in ixodes spp. cell lines.ixodes spp. ticks are known to occasionally harbour spiroplasmas - helical mycoplasmas in the class mollicutes; a previous study in slovakia reported an overall prevalence of spiroplasma ixodetis of 3% in ixodes ricinus. in the present study, extracts of unfed adult i. ricinus ticks collected from vegetation in south-western slovakia were added to a panel of cell lines derived from i. ricinus and ixodes scapularis embryos. the cultures were monitored by preparation and examination of giemsa-stai ...201526003954
anaplasmosis in a dog on vancouver island. 026130842
rickettsia buchneri sp. nov., a rickettsial endosymbiont of the blacklegged tick ixodes scapularis.we obtained a rickettsial isolate from the ovaries of the blacklegged tick, ixodes scapularis. the isolate (iso7(t)) was grown in the ixodes ricinus embryonic cell line ire11. we characterized the isolate by transmission electron microscopy and gene sequencing. phylogenetic analysis of 11 housekeeping genes demonstrated that the isolate fulfils the criteria to be classified as a representative of a novel rickettsial species closely related to 'rickettsia monacensis'. these rickettsiae form a cla ...201525563918
complex interactions within the ectoparasite community of the eastern rock sengi (elephantulus myurus).concomitant infection with more than one parasite species is the rule in nature. since co-infecting parasites are exploiting the same host, interspecific interactions at the infracommunity level are likely. the nature of such interactions can be expected to affect the distribution of parasites within host populations. intraspecific interactions within the infracommunity are not easily discernible from cross-sectional studies and the focus of most of these studies lies on relationships between en ...201525830115
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
experimental infection of rhipicephalus sanguineus with ehrlichia chaffeensis.ehrlichia chaffeensis, the etiologic agent of human monocytic ehrlichiosis, is a tick-borne rickettsial pathogen that is infective to a wide range of mammals, including dogs and people. amblyomma americanum, the lone star tick, is considered the primary vector of e. chaffeensis, but this pathogen has been detected in other tick species, including the brown dog tick, rhipicephalus sanguineus. we hypothesized that the arkansas strain of e. chaffeensis is infective to r. sanguineus, and used a nove ...201424894131
comparative genomics identifies a potential marker of human-virulent anaplasma phagocytophilum.we have previously described a comparative genome analysis of nine strains of anaplasma phagocytophilum that showed similarity between strains infecting humans and u.s. dogs and a more distant relationship with horse and ruminant strains. this suggested that it may be possible to distinguish human-infective strains using simple dna sequence-based diagnostic tests. this would be of epidemiologic significance in identifying and tracking the presence of virulent strains in tick vector populations. ...201425437606
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
emerging antigens involved in allergic responses.new allergic diseases can 'emerge' because of exposure to a novel antigen, because the immune responsiveness of the subject changes, or because of a change in the behavior of the population. novel antigens have entered the environment as new pests in the home (e.g., asian lady beetle or stink bugs), in the diet (e.g., prebiotics or wheat isolates), or because of the spread of a biting arthropod (e.g., ticks). over the last few years, a significant new disease has been identified, which has chang ...201324095162
structure of the type iv secretion system in different strains of anaplasma phagocytophilum.anaplasma phagocytophilum is an intracellular organism in the order rickettsiales that infects diverse animal species and is causing an emerging disease in humans, dogs and horses. different strains have very different cell tropisms and virulence. for example, in the u.s., strains have been described that infect ruminants but not dogs or rodents. an intriguing question is how the strains of a. phagocytophilum differ and what different genome loci are involved in cell tropisms and/or virulence. t ...201223190684
antigen variability in anaplasma phagocytophilum during chronic infection of a reservoir host.anaplasma phagocytophilum is an obligately intracellular, tick-transmitted, bacterial pathogen of humans and other animals. in order to evade host immunity during the course of infection, a. phagocytophilum utilizes gene conversion to shuffle approximately 100 functional pseudogenes into a single expression cassette of the msp2(p44) gene, which encodes the major surface antigen, major surface protein 2 (msp2). the role and extent of msp2(p44) recombination in a reservoir host for a. phagocytophi ...201222859615
anticoagulant rodenticides on our public and community lands: spatial distribution of exposure and poisoning of a rare forest carnivore.anticoagulant rodenticide (ar) poisoning has emerged as a significant concern for conservation and management of non-target wildlife. the purpose for these toxicants is to suppress pest populations in agricultural or urban settings. the potential of direct and indirect exposures and illicit use of ars on public and community forest lands have recently raised concern for fishers (martes pennanti), a candidate for listing under the federal endangered species act in the pacific states. in an invest ...201222808110
modelling transmission of vector-borne pathogens shows complex dynamics when vector feeding sites are limited.the relationship between species richness and the prevalence of vector-borne disease has been widely studied with a range of outcomes. increasing the number of host species for a pathogen may decrease infection prevalence (dilution effect), increase it (amplification), or have no effect. we derive a general model, and a specific implementation, which show that when the number of vector feeding sites on each host is limiting, the effects on pathogen dynamics of host population size are more compl ...201222590597
disintegrins from hematophagous sources.bloodsucking arthropods are a rich source of salivary molecules (sialogenins) which inhibit platelet aggregation, neutrophil function and angiogenesis. here we review the literature on salivary disintegrins and their targets. disintegrins were first discovered in snake venoms, and were instrumental in our understanding of integrin function and also for the development of anti-thrombotic drugs. in hematophagous animals, most disintegrins described so far have been discovered in the salivary gland ...201222778902
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
factorial microarray analysis of zebra mussel (dreissena polymorpha: dreissenidae, bivalvia) adhesion.the zebra mussel (dreissena polymorpha) has been well known for its expertise in attaching to substances under the water. studies in past decades on this underwater adhesion focused on the adhesive protein isolated from the byssogenesis apparatus of the zebra mussel. however, the mechanism of the initiation, maintenance, and determination of the attachment process remains largely unknown.201020509938
inclusion bodies in tick-borne diseases diagnosed in patients from northern wisconsin. 019574488
power evaluation of disease clustering tests.background: many different test statistics have been proposed to test for spatial clustering. some of these statistics have been widely used in various applications. in this paper, we use an existing collection of 1,220,000 simulated benchmark data, generated under 51 different clustering models, to compare the statistical power of several disease clustering tests. these tests are besag-newell's r, cuzick-edwards' k-nearest neighbors (k-nn), the spatial scan statistic, tango's maximized excess e ...200314687424
diversity of rickettsial pathogens in columbian black-tailed deer and their associated keds (diptera: hippoboscidae) and ticks (acari: ixodidae).cervids host multiple species of ixodid ticks, other ectoparasites, and a variety of rickettsiae. however, diagnostic test cross-reactivity has precluded understanding the specific role of deer in rickettsial ecology. in our survey of 128 columbian black-tailed deer (odocoileus hemionus columbianus (richardson)) and their arthropod parasites from two northern californian herds, combined with reports from the literature, we identified four distinct anaplasma spp. and one ehrlichia species. two ke ...201627232123
epidemiology and genetic diversity of anaplasma phagocytophilum in the san francisco bay area, california.in california, the agent of human granulocytic anaplasmosis (hga), anaplasma phagocytophilum, is transmitted by western black-legged ticks (ixodes pacificus). cases of hga are infrequent in california but do occur annually. we investigated nymphal and adult western black-legged tick populations in 20 recreational areas in california's san francisco bay area (marin, napa, san mateo, santa clara, santa cruz, and sonoma counties). overall, prevalence of a. phagocytophilum in adult ticks was 0.8% (1 ...201627139447
a putative marker for human pathogenic strains of anaplasma phagocytophilum correlates with geography and host, but not human tropism.anaplasma phagocytophilum is an ixodes species tick-transmitted bacterium that is capable of infecting a variety of host species, although there is a diversity of bacterial strains with differing host tropism. recent analysis of a. phagocytophilum strains suggested that "drhm", a gene locus designated "distantly related to human marker" (drhm), which was predicted to be an integral membrane protein with possible transporter functions was not present in available canine and human isolates. by ass ...201626748871
lyme disease coinfections in the united states.lyme disease in north america is caused by infection with the spirochetal bacterium borrelia burgdorferi and transmitted by ixodes scapularis and ixodes pacificus ticks. these ticks also have the potential to transmit a rapidly expanding list of other pathogenic bacteria, viruses, and parasites, including anaplasma phagocytophilum, babesia microti, deer tick (powassan) virus, borrelia miyamotoi, and the ehrlichia muris-like organism. coinfections with b burgdorferi and these other agents are oft ...201526593260
a real-time pcr assay for differentiating pathogenic anaplasma phagocytophilum from an apathogenic, woodrat-adapted genospecies from north america.anaplasma phagocytophilum is a tick-transmitted bacterial pathogen of humans and animals comprising strains that cause clinical disease in people, dogs and horses (the pathogenic a. phagocytophilum "genospecies") and more distantly related strains. a rodent-adapted genospecies named du1, found primarily in woodrats, is unable to infect horses. we developed a real-time pcr (rt-pcr) assay, which targets an 85 base pair region of the ank gene and is specific for the pathogenic genospecies of a. pha ...201526188998
surveillance for ixodes pacificus and the tick-borne pathogens anaplasma phagocytophilum and borrelia burgdorferi in birds from california's inner coast range.we investigated the involvement of birds in the ecology of the western black-legged tick, ixodes pacificus, and its associated zoonotic bacteria, borrelia burgdorferi and anaplasma phagocytophilum, at two interior coast-range study sites in northern california. anaplasma phagocytophilum, the agent of granulocytic anaplasmosis (ga), and b. burgdorferi s.s., the agent of lyme disease (ld), are tick-borne pathogens that are well established in california. we screened blood and ticks from 349 indivi ...201424690191
paired real-time pcr assays for detection of borrelia miyamotoi in north american ixodes scapularis and ixodes pacificus (acari: ixodidae).borrelia miyamotoi is an emerging, tick-borne human pathogen. in north america, it is primarily associated with ixodes scapularis and ixodes pacificus, two species known to bite humans. here we describe the development and evaluation of a pair of real-time taqman pcr assays designed to detect b. miyamotoi in north american ticks. we sought to achieve sensitivity to b. miyamotoi strains associated with ticks throughout north america, the full genetic diversity of which is unknown, by targeting se ...201627475875
remarkable diversity of tick or mammalian-associated borreliae in the metropolitan san francisco bay area, california.the diversity of lyme disease (ld) and relapsing fever (rf)-group spirochetes in the metropolitan san francisco bay area in northern california is poorly understood. we tested ixodes pacificus, i. spinipalpis, and small mammals for presence of borreliae in alameda county in the eastern portion of san francisco bay between 2009 and 2012. analyses of 218 borrelia burgdorferi sensu lato (bb sl) culture or dna isolates recovered from host-seeking i. pacificus ticks revealed that the human pathogen b ...201425129859
detection of borrelia genomospecies 2 in ixodes spinipalpis ticks collected from a rabbit in canada.lyme disease is a serious health problem, with many patients requiring in-depth clinical assessment and extended treatment. in the present study, we provide the first records of the western blacklegged tick, ixodes pacificus , and ixodes spinipalpis parasitizing eastern cottontails, sylvilagus floridanus . we also documented a triple co-infestation of 3 tick species (ixodes angustus, i. pacificus , i. spinipalpis) feeding on an eastern cottontail. notably, we discovered a unique member of the ly ...201727835071
eco-epidemiological factors contributing to the low risk of human exposure to ixodid tick-borne borreliae in southern california, usa.little is known about the eco-epidemiology of lyme disease in southern california, a region where the incidence is much lower than it is in northern california. here, we sought to discover the previously unknown microhabitats of nymphs of the primary vector, the western black-legged tick (ixodes pacificus), in 3 moderately to heavily-utilized state parks in the santa monica mountains in los angeles county; to elucidate the seasonal distribution and abundance of adults of i. pacificus and another ...201323643357
modeling the geographic distribution of ixodes scapularis and ixodes pacificus (acari: ixodidae) in the contiguous united states.in addition to serving as vectors of several other human pathogens, the black-legged tick, ixodes scapularis say, and western black-legged tick, ixodes pacificus cooley and kohls, are the primary vectors of the spirochete (borrelia burgdorferi) that causes lyme disease, the most common vector-borne disease in the united states. over the past two decades, the geographic range of i. pacificus has changed modestly while, in contrast, the i. scapularis range has expanded substantially, which likely ...201627282813
county-scale distribution of ixodes scapularis and ixodes pacificus (acari: ixodidae) in the continental united states.the blacklegged tick, ixodes scapularis say, is the primary vector to humans in the eastern united states of the lyme disease spirochete borrelia burgdorferi, as well as causative agents of anaplasmosis and babesiosis. its close relative in the far western united states, the western blacklegged tick ixodes pacificus cooley and kohls, is the primary vector to humans in that region of the lyme disease and anaplasmosis agents. since 1991, when standardized surveillance and reporting began, lyme dis ...201626783367
linkages of weather and climate with ixodes scapularis and ixodes pacificus (acari: ixodidae), enzootic transmission of borrelia burgdorferi, and lyme disease in north america.lyme disease has increased both in incidence and geographic extent in the united states and canada over the past two decades. one of the underlying causes is changes during the same time period in the distribution and abundance of the primary vectors: ixodes scapularis say and ixodes pacificus cooley and kohls in eastern and western north america, respectively. aside from short periods of time when they are feeding on hosts, these ticks exist in the environment where temperature and relative hum ...201626681789
methods to prevent tick bites and lyme disease.current approaches for prevention of tick bites, lyme disease, and other tick-borne diseases are described. particular attention is paid to 4 risk-reduction strategies: (i) avoiding risk areas; (ii) personal protective measures that reduce the risk of tick bites or transmission of the agent of lyme disease, borrelia burgdorferi; (iii) reducing the number of infected ticks in the environment; and (iv) use of prophylactic antibiotic treatments following a bite to prevent clinical lyme disease.201526593263
truncated seasonal activity patterns of the western blacklegged tick (ixodes pacificus) in central and southern california.patterns of seasonal activity and density of host-seeking western blacklegged ticks, ixodes pacificus, were investigated in central and southern california. weekly to monthly drag sampling was undertaken at two sites in santa barbara county and one site in los angeles county over multiple years. adult i. pacificus became active in the winter (late november) and were rare or absent by late april to early may. nymphal ticks became active in early to late february, were absent by early may to early ...201626564403
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. ...201526336263
effects of temperature on feeding duration, success, and efficiency of larval western black-legged ticks (acari: ixodidae) on western fence lizards.the western black-legged tick (ixodes pacificus) is a common tick species throughout the western usa and is the major vector for borrelia burgdorferi, the lyme disease causing bacterium. western fence lizards (sceloporus occidentalis) are a major host for juvenile i. pacificus, but are incompetent hosts for b. burgdorferi, which makes this host-parasite relationship of particular interest. in order to shed further light on this complex host-parasite relationship, we investigated the effects of t ...201526188858
comparative genetic diversity of lyme disease bacteria in northern californian ticks and their vertebrate hosts.vector-borne pathogens are transmitted between vertebrate hosts and arthropod vectors, two immensely different environments for the pathogen. there is further differentiation among vertebrate hosts that often have complex, species-specific immunological responses to the pathogen. all this presents a heterogeneous environmental and immunological landscape with possible consequences on the population genetic structure of the pathogen. we evaluated the differential genetic diversity of the lyme dis ...201525843810
seasonal activity patterns of the western black-legged tick, ixodes pacificus, in relation to onset of human lyme disease in northwestern california.seasonal activity patterns of questing western black-legged ticks, ixodes pacificus were investigated in northwestern california. adult i. pacificus became active in the fall (late october/early november) and their appearance was associated with the first rain of the season. following a peak in january, the abundance of adult ticks declined such that they were rare or absent by june/july. the nymphal tick activity season occurred from january through october, and larval activity occurred from ap ...201425113980
diversity of rickettsiae in a rural community in northern california.far northern california forests are highly biodiverse in wildlife reservoirs and arthropod vectors that may propagate rickettsial pathogens in nature. the proximity of small rural communities to these forests puts people and domestic animals at risk of vector-borne infection due to spillover from wildlife. the current study was conducted to document exposure to rickettsial pathogens in people and domestic animals in a rural community, and identify which rickettsiae are present in sylvatic and pe ...201728274808
manual for maintenance of multi-host ixodid ticks in the laboratory.use of laboratory animals as hosts for blood-sucking arthropods remains a time-proven and the most efficient method for establishment and propagation of slowly feeding ixodid ticks, despite introduction of techniques involving artificial feeding on either animal skins or synthetic membranes. new zealand white rabbits are usually the most accessible and most suitable hosts routinely used for establishment and maintenance of a large variety of multi-host tick species. here we describe standard pro ...201627651325
borrelia bissettiae sp. nov. and borrelia californiensis sp. nov. prevail in diverse enzootic transmission cycles.two borrelia species, borrelia bissettiae sp. nov. and borrelia californiensis sp. nov., were first described by postic and co-workers (postic et al., 2007; postic et al., 1998) based on genetic analyses of several loci. multilocus sequence analysis (mlsa) of eight housekeeping loci confirmed that these two borrelia genospecies are distinct members of the b. burgdorferi s. l. complex (margos et al., 2010). b. bissettiae sp. nov. initially was described in transmission cycles involving neotoma fu ...201626813420
Displaying items 401 - 500 of 512