Publications

TitleAbstractYear(sorted descending)
Filter
PMID
Filter
prevalence and geographic distribution of borrelia miyamotoi in host-seeking ixodes pacificus (acari: ixodidae) nymphs in mendocino county, california.borrelia miyamotoi is an increasingly recognized human pathogen transmitted by ixodes ticks in the northern hemisphere. in north america, infection prevalences of b. miyamotoi are characteristically low (<10%) in ixodes scapularis (say; acari: ixodidae) and ixodes pacificus (cooley & kohls; acari: ixodidae), both of which readily bite humans. we tested 3,255 host-seeking i. pacificus nymphs collected in 2004 from 79 sites throughout mendocino county in north-coastal california for presence of b. ...201829365130
the fola gene from the rickettsia endosymbiont of ixodes pacificus encodes a functional dihydrofolate reductase enzyme.although nonpathogenic bacterial endosymbionts have been shown to contribute to their arthropod host's fitness by supplying them with essential vitamins and amino acids, little is known about the nutritional basis for the symbiotic relationship of endosymbionts in ticks. our lab has previously reported that rickettsia species phylotype g021 in ixodes pacificus carries all five genes for de novo folate synthesis, and that these genes are monophyletic with homologs from other rickettsia species. i ...201729284564
chromosome and large linear plasmid sequences of a borrelia miyamotoi strain isolated from ixodes pacificus ticks from california.borrelia miyamotoi, a relapsing fever group spirochete, is an emerging tick-borne pathogen. it has been identified in ixodid ticks across the northern hemisphere, including the west coast of the united states. we describe the chromosome and large linear plasmid sequence of a b. miyamotoi isolate cultured from a california field-collected ixodes pacificus tick.201728912318
enhanced detection of rickettsia species in ixodes pacificus using highly sensitive fluorescence in situ hybridization coupled with tyramide signal amplification.ixodes pacificus is a host of many bacteria including rickettsia species phylotypes g021 and g022. as part of the overall goal of understanding interactions of phylotypes with their tick host, this study focused on molecular detection of rickettsiae in ovarian and midgut tissue of i. pacificus by fluorescent in situ hybridization (fish), pcr, and ultrastructural analysis. of three embedding media (technovit 8100, unicryl, and paraffin) tested for generating thin sections, tissues embedded in par ...201728882513
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
host-seeking phenology of ixodes pacificus (acari: ixodidae) nymphs in northwestern california in relation to calendar week, woodland type, and weather conditions.local knowledge of when humans are at elevated risk for exposure to tick vectors of human disease agents is required both for the effective use of personal protection measures to avoid tick bites and for implementation of control measures to suppress host-seeking ticks. here, we used previously published data on the seasonal density of host-seeking ixodes pacificus cooley and kohls nymphs, the primary vectors of lyme disease spirochetes in the far western usa, collected across a broad habitat an ...201728082639
a molecular algorithm to detect and differentiate human pathogens infecting ixodes scapularis and ixodes pacificus (acari: ixodidae).the incidence and geographic range of tick-borne illness associated with ixodes scapularis and ixodes pacificus have dramatically increased in recent decades. anaplasmosis, babesiosis, and borrelia spirochete infections, including lyme borreliosis, account for tens of thousands of reported cases of tick-borne disease every year. assays that reliably detect pathogens in ticks allow investigators and public health agencies to estimate the geographic distribution of human pathogens, assess geograph ...201729258802
vertical vs. horizontal transmission of the microbiome in a key disease vector, ixodes pacificus.vector-borne pathogens are increasingly found to interact with the vector's microbiome, influencing disease transmission dynamics. however, the processes that regulate the formation and development of the microbiome are largely unexplored for most tick species, an emerging group of disease vectors. it is not known how much of the tick microbiome is acquired through vertical transmission vs. horizontally from the environment or interactions with bloodmeal sources. using 16s rrna sequencing, we ex ...201729178531
tick microbiome and pathogen acquisition altered by host blood meal.lyme disease, a zoonotic disease, is the most prevalent vector-borne disease in the northern hemisphere. diversity of the vector (tick) microbiome can impact pathogen transmission, yet the biotic and abiotic factors that drive microbiome diversity are largely unresolved, especially under natural, field conditions. we describe the microbiome of ixodes pacificus ticks, the vector for lyme disease in the western united states, and show a strong impact of host blood meal identity on tick microbiome ...201727858931
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
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
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
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
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
unique strain of borrelia miyamotoi in ixodes pacificus ticks, california, usa. 201627479523
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
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
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
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
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
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
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
diapause in ticks of the medically important ixodes ricinus species complex.four members of the ixodes ricinus species complex, ixodes pacificus, ixodes persulcatus, ixodes ricinus and ixodes scapularis, have, between them, a worldwide distribution within the northern hemisphere. they are responsible for the transmission of several animal and human pathogens, including the causal agents of lyme borreliosis, tick-borne encephalitis, human granulocytic anaplasmosis and human babesiosis. despite the importance of these ticks as vectors, the knowledge and understanding of t ...201627263092
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
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
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
human behaviors elevating the risk of exposure to ixodes ricinus larvae and nymphs in two types of lowland coniferous forests in west-central poland.ixodes ricinus l. is the commonest tick encountered by humans in central europe and the most important vector of tick-borne diseases (tbd) in europe. foresters represent a group at elevated risk of exposure to i. ricinus throughout europe. here, we employed an experimental design similar to one used previously to determine what behavioral factors heighten exposure to questing ixodes pacificus nymphs in a hardwood forest in the far-western united states. five activities were evaluated systematica ...201627499188
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
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
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
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
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
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
gis and remote sensing use in the exploration of lyme disease epidemiology.given the relatively recent recognition of lyme disease (ld) by cdc in 1990 as a nationally notifiable infectious condition, the rise of reported human cases every year argues for a better understanding of its geographic scope. the aim of this inquiry was to explore research conducted on spatiotemporal patterns of lyme disease in order to identify strategies for implementing vector and reservoir-targeted interventions. the focus of this review is on the use of gis-based methods to study populati ...201526633445
human coinfection with borrelia burgdorferi and babesia microti in the united states.borrelia burgdorferi, the causative agent of lyme disease, and babesia microti, a causative agent of babesiosis, are increasingly implicated in the growing tick-borne disease burden in the northeastern united states. these pathogens are transmitted via the bite of an infected tick vector, ixodes scapularis, which is capable of harboring and inoculating a host with multiple pathogens simultaneously. clinical presentation of the diseases is heterogeneous and ranges from mild flu-like symptoms to n ...201526697208
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
evaluation of selected borrelia burgdorferi lp54 plasmid-encoded gene products expressed during mammalian infection as antigens to improve serodiagnostic testing for early lyme disease.laboratory testing for the diagnosis of lyme disease is performed primarily by serologic assays and is accurate for detection beyond the acute stage of the infection. serodiagnostic assays to detect the early stages of infection, however, are limited in their sensitivity, and improvement is warranted. we analyzed a series of borrelia burgdorferi proteins known to be induced within feeding ticks and/or during mammalian infection for their utility as serodiagnostic markers against a comprehensive ...201526376927
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
tick-borne pathogens in northwestern california, usa. 201424565119
an ixodes minor and borrelia carolinensis enzootic cycle involving a critically endangered mojave desert rodent.microtus californicus scirpensis is an endangered, isolated subspecies of california vole. it requires water pools and riparian bulrush (schoenoplectus americanus) and occupies some of the rarest habitat of any north american mammal. the minimally vegetated, extremely arid desert surrounding the pools is essentially uninhabitable for ixodes species ticks. we describe an enzootic cycle of borrelia carolinensis in ixodes minor ticks at a site 3500 km distant from the region in which i. minor is kn ...201425035799
insecticide/acaricide resistance in fleas and ticks infesting dogs and cats.this review defines insecticide/acaricide resistance and describes the history, evolution, types, mechanisms, and detection of resistance as it applies to chemicals currently used against fleas and ticks of dogs and cats and summarizes resistance reported to date. we introduce the concept of refugia as it applies to flea and tick resistance and discuss strategies to minimize the impact and inevitable onset of resistance to newer classes of insecticides. our purpose is to provide the veterinary p ...201424393426
detection of lyme borrelia in questing ixodes scapularis (acari: ixodidae) and small mammals in louisiana.lyme borreliosis is caused by spirochetes from the borrelia burgdorferi sensu lato species complex. in the united states, b. burgdorferi sensu stricto (s.s.; johnson, schmid, hyde, steigerwalt, and brenner) is the most common cause of human lyme borreliosis. with >25,000 cases reported annually, it is the most common vector-borne disease in the united states. although approximately 90% of cases are contained to the northeastern and great lake states, areas in canada and some southern states are ...201424605479
emergence of ixodes scapularis and borrelia burgdorferi, the lyme disease vector and agent, in ohio.lyme disease, the most common vector-borne disease in the united states, is caused by a tick-borne infection with borrelia burgdorferi. currently, ohio is considered by the centers for disease control and prevention (cdc) to be non-endemic for lyme disease. the low incidence of lyme disease in this state was largely attributed to the absence of the transmitting vector, ixodes scapularis, commonly known as the blacklegged tick. however, a tick surveillance program established by ohio department o ...201424926441
genetic diversity of salp15 in the ixodes ricinus complex (acari: ixodidae).salp15, a 15-kda tick salivary gland protein, is both essential for ticks to successfully obtain host blood and also facilitates transmission of lyme borreliosis. to determine whether the salp15 gene is expressed in ixodes persulcatus and ixodes sinensis, principle vectors of lyme borreliosis in china, we studied transcriptions of this gene in semi-engorged larvae, nymph and adults of these two species. a total of eight salp15 homologues, five in i. persulcatus and three in i. sinensis, were ide ...201424714063
the relapsing fever spirochete borrelia miyamotoi is cultivable in a modified kelly-pettenkofer medium, and is resistant to human complement.borrelia miyamotoi is a relapsing fever spirochete found in ixodes ticks in north america, europe, and asia, and has recently been found to be invasive in humans. cultivation of this spirochete has not yet been described, but is important for patient diagnostics and scientific purposes. host specificity of borrelia species is dependent on resistance to host complement (serum resistance), and since b. miyamotoi has been identified as a human pathogen we were interested whether b. miyamotoi is res ...201425189195
serological and molecular prevalence of selected canine vector borne pathogens in blood donor candidates, clinically healthy volunteers, and stray dogs in north carolina.canine vector borne diseases (cvbds) comprise illnesses caused by a spectrum of pathogens that are transmitted by arthropod vectors. some dogs have persistent infections without apparent clinical, hematological or biochemical abnormalities, whereas other dogs develop acute illnesses, persistent subclinical infections, or chronic debilitating diseases. the primary objective of this study was to screen healthy dogs for serological and molecular evidence of regionally important cvbds.201424655461
high seroprevalence of borrelia miyamotoi antibodies in forestry workers and individuals suspected of human granulocytic anaplasmosis in the netherlands.substantial exposure to borrelia miyamotoi occurs through bites from ixodes ricinus ticks in the netherlands, which also transmit borrelia burgdorferi sensu lato and anaplasma phagocytophilum. direct evidence for b. miyamotoi infection in european populations is scarce. a flu-like illness with high fever, resembling human granulocytic anaplasmosis, has been attributed to b. miyamotoi infections in relatively small groups. borrelia miyamotoi infections associated with chronic meningoencephalitis ...201425356364
population-based passive tick surveillance and detection of expanding foci of blacklegged ticks ixodes scapularis and the lyme disease agent borrelia burgdorferi in ontario, canada.we identified ticks submitted by the public from 2008 through 2012 in ontario, canada, and tested blacklegged ticks ixodes scapularis for borrelia burgdorferi and anaplasma phagocytophilum. among the 18 species of ticks identified, i. scapularis, dermacentor variabilis, ixodes cookei and amblyomma americanum represented 98.1% of the 14,369 ticks submitted. rates of blacklegged tick submission per 100,000 population were highest in ontario's eastern region; d. variabilis in central west and easte ...201425171252
irspi, a tick serine protease inhibitor involved in tick feeding and bartonella henselae infection.ixodes ricinus is the most widespread and abundant tick in europe, frequently bites humans, and is the vector of several pathogens including those responsible for lyme disease, tick-borne encephalitis, anaplasmosis, babesiosis and bartonellosis. these tick-borne pathogens are transmitted to vertebrate hosts via tick saliva during blood feeding, and tick salivary gland (sg) factors are likely implicated in transmission. in order to identify such tick factors, we characterized the transcriptome of ...201425057911
population and demographic structure of ixodes scapularis say in the eastern united states.the most significant vector of tick-borne pathogens in the united states is ixodes scapularis say (the blacklegged tick). previous studies have identified significant genetic, behavioral and morphological differences between northern vs. southern populations of this tick. because tick-borne pathogens are dependent on their vectors for transmission, a baseline understanding of the vector population structure is crucial to determining the risks and epidemiology of pathogen transmission.201425025532
a 24-48 h fed amblyomma americanum tick saliva immuno-proteome.multiple tick saliva proteins, the majority of which are unknown, confer tick resistance in repeatedly infested animals. the objective of this study was to identify the 24-48 h fed amblyomma americanum tick saliva immuno-proteome. the 24-48 h tick-feeding phase is critical to tick parasitism as it precedes important events in tick biology, blood meal feeding and disease agent transmission. fed male, 24 and 96 h fed female phage display cdna expression libraries were biopanned using rabbit antibo ...201424962723
stage-specific global alterations in the transcriptomes of lyme disease spirochetes during tick feeding and following mammalian host adaptation.borrelia burgdorferi, the agent of lyme disease, is maintained in nature within an enzootic cycle involving a mammalian reservoir and an ixodes sp. tick vector. the transmission, survival and pathogenic potential of b. burgdorferi depend on the bacterium's ability to modulate its transcriptome as it transits between vector and reservoir host. herein, we employed an amplification-microarray approach to define the b. burgdorferi transcriptomes in fed larvae, fed nymphs and in mammalian host-adapte ...201425425211
borrelia burgdorferi (lyme disease). 201425452659
molecular characterization of borrelia burgdorferi from case of autochthonous lyme arthritis. 201425423131
the first case of locally acquired tick-borne babesia microti infection in canada.a child with a complicated medical history that included asplenia acquired an infection with babesia microti in the summer of 2013 and had not travelled outside of manitoba. although the clinical findings were subtle, astute laboratory work helped to reach a preliminary identification of babesia species, while reference laboratory testing confirmed the diagnosis. blacklegged ticks (ixodes scapularis) are known to transmit borrelia burgdorferi and anaplasma phagocytophilum in the province; howeve ...201425587297
efficacy and safety of pharmacological treatments for neuroborreliosis--protocol for a systematic review.neuroborreliosis is a tick-borne infectious disease of the nervous system caused by borrelia burgdorferi. common clinical manifestations of neuroborreliosis are cranial nerve dysfunctions, polyradiculoneuritis, and meningitis. diagnosis is usually based on clinical presentation, serologic testing, and analysis of cerebrospinal fluid. many aspects of pharmacological treatment, such as choice of drug, dosage, and duration are subject of intense debate, leading to uncertainties in patients and heal ...201425336085
large scale spatial risk and comparative prevalence of borrelia miyamotoi and borrelia burgdorferi sensu lato in ixodes pacificus.borrelia miyamotoi is a newly described emerging pathogen transmitted to people by ixodes species ticks and found in temperate regions of north america, europe, and asia. there is limited understanding of large scale entomological risk patterns of b. miyamotoi and of borreila burgdorferi sensu stricto (ss), the agent of lyme disease, in western north america. in this study, b. miyamotoi, a relapsing fever spirochete, was detected in adult (n=70) and nymphal (n=36) ixodes pacificus ticks collecte ...201425333277
case 2: a seven-year-old girl with diplopia. 201425382993
lyme disease in canada: focus on children.lyme disease, the most common tick-borne infection in canada and much of the united states, is caused by the bacteria borrelia burgdorferi. peak incidence for lyme disease is among children five to nine years of age and older adults (55 to 59 years of age). the bacteria are transmitted through the bite of infected black-legged ticks of the ixodes species. the primary hosts of black-legged ticks are mice and other rodents, small mammals, birds (which are reservoirs for b burgdorferi) and white-ta ...201425332678
co-infection of blacklegged ticks with babesia microti and borrelia burgdorferi is higher than expected and acquired from small mammal hosts.humans in the northeastern and midwestern united states are at increasing risk of acquiring tickborne diseases--not only lyme disease, but also two emerging diseases, human granulocytic anaplasmosis and human babesiosis. co-infection with two or more of these pathogens can increase the severity of health impacts. the risk of co-infection is intensified by the ecology of these three diseases because all three pathogens (borrelia burgdorferi, anaplasma phagocytophilum, and babesia microti) are tra ...201424940999
the prevalence of borrelia miyamotoi infection, and co-infections with other borrelia spp. in ixodes scapularis ticks collected in canada.blacklegged ticks, ixodes scapularis are vectors of the tick-borne pathogens borrelia burgdorferi, anaplasma phagocytophilum and babesia microti. recently, the i. scapularis-borne bacterium borrelia miyamotoi has been linked to human illness in north america. the range of this tick is expanding in canada which may increase the potential for human exposure to these agents.201424731287
comparative bioinformatics, temporal and spatial expression analyses of ixodes scapularis organic anion transporting polypeptides.organic anion-transporting polypeptides (oatps) are an integral part of the detoxification mechanism in vertebrates and invertebrates. these cell surface proteins are involved in mediating the sodium-independent uptake and/or distribution of a broad array of organic amphipathic compounds and xenobiotic drugs. this study describes bioinformatics and biological characterization of 9 oatp sequences in the ixodes scapularis genome. these sequences have been annotated on the basis of 12 transmembrane ...201424582512
vector biodiversity did not associate with tick-borne pathogen prevalence in small mammal communities in northern and central california.vector and host abundance affect infection transmission rates, prevalence, and persistence in communities. biological diversity in hosts and vectors may provide "rescue" hosts which buffer against pathogen extinction and "dilution" hosts which reduce the force of infection in communities. anaplasma phagocytophilum is a tick-transmitted zoonotic pathogen that circulates in small mammal and tick communities characterized by varying levels of biological diversity. we examined the prevalence of a. p ...201424582513
the western progression of lyme disease: infectious and nonclonal borrelia burgdorferi sensu lato populations in grand forks county, north dakota.scant attention has been paid to lyme disease, borrelia burgdorferi, ixodes scapularis, or reservoirs in eastern north dakota despite the fact that it borders high-risk counties in minnesota. recent reports of b. burgdorferi and i. scapularis in north dakota, however, prompted a more detailed examination. spirochetes cultured from the hearts of five rodents trapped in grand forks county, nd, were identified as b. burgdorferi sensu lato through sequence analyses of the 16s rrna gene, the 16s rrna ...201425304515
Displaying items 1 - 100 of 512