| rickettsia rickettsii and rickettsia montana from ixodid ticks in connecticut. | dermacentor variabilis, infected with spotted fever group rickettsiae, parasitized 8 of 70 raccoons captured in newtown, connecticut. the spotted fever agent, rickettsia rickettsii, was isolated and identified from 4 adult d. variabilis and from 1 nymphal ixodes texanus removed from raccoons. this verifies the presence of this etiologic agent in ticks in an area where 6 people had clinical signs and symptoms of rocky mountain spotted fever (rmsf) and antibodies to r. rickettsii. these are the fi ... | 1986 | 3946737 |
| the borrelia burgdorferi circular plasmid cp26: conservation of plasmid structure and targeted inactivation of the ospc gene. | the 26 to 28kb circular plasmid of b. burgdorferi sensu lato (cp26) is ubiquitous among bacteria of this group and contains loci implicated in the mouse-tick transmission cycle. restriction mapping and southern hybridization indicated that the structure of cp26 is conserved among isolates from different origins and culture passage histories. the cp26 ospc gene encodes an outer surface protein whose synthesis within infected ticks increases when the ticks feed, and whose synthesis in culture incr ... | 1997 | 9282748 |
| parallel discrete event simulation of lyme disease. | our research concerns the dynamic processes underlying the rapid increase in the geographic distribution of lyme disease, currently the most frequently reported vector-borne disease of humans in the united states [10, 1]. more specifically, we ask how spatially localized ecological interactions drive the lyme disease epidemic at extended spatial and temporal scales. we have developed a parallel discrete event simulation system in c++ for the ibm sp2. the simulation model discussed here models th ... | 1996 | 9390232 |
| severe reaction in domestic animals following the bite of ixodes muris (acari: ixodidae). | free tick identification has been offered by our laboratory since 1989, during which time > 8,000 specimens have been submitted. we have noted that the bite of 1 of the less frequently identified ticks, ixodes muris bishopp & smith, may be associated with a severe reaction in domestic animals characterized by extreme pain and swelling at the site and, with more complete engorgement, lethargy, anorexia, and high fever. these symptoms may be confused with other serious illness if the tick is not f ... | 1999 | 10337088 |
| molecular genetic key for the identification of 17 ixodes species of the united states (acari:ixodidae): a methods model. | a taxonomic key, based on restriction enzyme analysis of the second internal-transcribed spacer (its-2) in the nuclear ribosomal dna gene, was developed for identification of 17 ixodes tick species in the united states. this key includes: ixodes affinis neumann, ixodes angustus neumann, ixodes baergi cooley and kohls, ixodes brunneus koch, ixodes cookei packard, ixodes dentatus marx, ixodes jellisoni cooley and kohls, ixodes kingi bishopp, ixodes minor neumann, ixodes muris bishopp and smith, ix ... | 1999 | 10461941 |
| vector competence of ixodes muris (acari: ixodidae) for borrelia burgdorferi. | the vector competence of ixodes muris (bishopp & smith) was determined for borrelia burgdorferi, the etiologic agent of lyme disease. larval i. muris were fed on icr outbred mice infected with the b-31 laboratory strain of b. burgdorferi. replete larvae, at 5 d after feeding, were assayed for infection by culture in barbour-stoner-kelly (bsk-h) media. infection frequency in i. muris replete larvae was 66%. resultant nymphs were fed on naive icr outbred mice to determine the ability of i. muris t ... | 2000 | 11004792 |
| birds disperse ixodid (acari: ixodidae) and borrelia burgdorferi-infected ticks in canada. | a total of 152 ixodid ticks (acari: ixodidae) consisting of nine species was collected from 82 passerine birds (33 species) in 14 locations in canada from 1996 to 2000. the lyme disease spirochete borrelia burgdorferi johnson, schmidt, hyde, steigerwaldt & brenner was cultured from the nymph of a blacklegged tick, ixodes scapularis say, that had been removed from a common yellowthroat, geothlypis trichas l., from bon portage island, nova scotia. as a result of bird movement, a nymphal i. scapula ... | 2001 | 11476328 |
| clonal polymorphism of borrelia burgdorferi strain b31 mi: implications for mutagenesis in an infectious strain background. | a major obstacle to studying the functions of particular gene products in the mouse-tick infectious cycle of borrelia burgdorferi has been an inability to knock out genes in pathogenic strains. here, we investigated conditions for site-directed mutagenesis in b31 mi, the low-passage-number, infectious b. burgdorferi strain whose genome was sequenced. we inactivated several plasmid and chromosomal genes in b31 mi and determined that clones carrying these mutations were not infectious for mice. ho ... | 2002 | 11895980 |
| population dynamics of a heterogeneous borrelia burgdorferi b31 strain in an experimental mouse-tick infectious cycle. | we have recently shown that low-passage, infectious borrelia burgdorferi strain b31 mi is a heterogeneous mixture of clones varying in colony morphology, growth rate, protein profiles, plasmid content and infectivity. in this study, we asked whether there is a selection for certain clonal populations during the infectious cycle when uncloned b31 mi is used as the starting strain. b31 mi derivatives were reisolated from various tissues of two mice after completion of a mouse-tick-mouse infectious ... | 2002 | 12422601 |
| plasmid stability during in vitro propagation of borrelia burgdorferi assessed at a clonal level. | borrelia burgdorferi causes lyme disease in humans. the genome of the sequenced type strain b31 mi consists of a linear chromosome, 12 linear plasmids, and 9 circular plasmids. previous studies by other investigators indicated that some of these plasmids are essential for the survival of the spirochetes in vivo but not in vitro. we have studied plasmid stability during in vitro growth at 23 and 35 degrees c, conditions that approximate the temperatures of the tick vector and the mammalian host, ... | 2003 | 12761092 |
| infectious cycle analysis of a borrelia burgdorferi mutant defective in transport of chitobiose, a tick cuticle component. | chitobiose is the dimer subunit of chitin, a component of tick cuticle and peritrophic matrix, which is not found in mammals. the borrelia burgdorferi chbc gene is required for the use of chitobiose as a source of the essential nutrient n-acetyl glucosamine during growth in vitro. in order to investigate the role of chitobiose transport in the infectious cycle, we constructed isogenic chbc mutant and wild-type strains in an infectious b. burgdorferi background and confirmed that the mutants were ... | 2004 | 15228817 |
| borrelia burgdorferi lacking bbk32, a fibronectin-binding protein, retains full pathogenicity. | bbk32, a fibronectin-binding protein of borrelia burgdorferi, is one of many surface lipoproteins that are differentially expressed by the lyme disease spirochete at various stages of its life cycle. the level of bbk32 expression in b. burgdorferi is highest during infection of the mammalian host and lowest in flat ticks. this temporal expression profile, along with its fibronectin-binding activity, strongly suggests that bbk32 may play an important role in lyme pathogenesis in the host. to test ... | 2006 | 16714558 |
| borrelia burgdorferi ospc protein required exclusively in a crucial early stage of mammalian infection. | this study demonstrates a strict temporal requirement for a virulence determinant of the lyme disease spirochete borrelia burgdorferi during a unique point in its natural infection cycle, which alternates between ticks and small mammals. ospc is a major surface protein produced by b. burgdorferi when infected ticks feed but whose synthesis decreases after transmission to a mammalian host. we have previously shown that spirochetes lacking ospc are competent to replicate in and migrate to the sali ... | 2006 | 16714588 |
| confirmation of tick bite by detection of antibody to ixodes calreticulin salivary protein. | ticks introduce a variety of pharmacologically active molecules into their host during attachment and feeding in order to obtain a blood meal. people who are repeatedly exposed to ticks may develop an immune response to tick salivary proteins. despite this response, people usually are unaware of having been bitten, especially if they are not repeatedly exposed to ticks. in order to develop a laboratory marker of tick exposure that would be useful in understanding the epidemiology of tick-borne i ... | 2006 | 16928887 |
| migratory songbirds disperse ticks across canada, and first isolation of the lyme disease spirochete, borrelia burgdorferi, from the avian tick, ixodes auritulus. | during a 3-yr comprehensive study, 196 ixodid ticks (9 species) were collected from 89 passerine birds (32 species) from 25 localities across canada to determine the distribution of avian-associated tick species and endogenous lyme disease spirochetes, borrelia burgdorferi johnson, schmid, hyde, steigerwalt, and brenner. we report the following first records of tick parasitism on avian hosts: the rabbit-associated tick, ixodes dentatus marx, from manitoba and ontario; the mouse tick, ixodes muri ... | 2005 | 17089744 |
| role of migratory birds in introduction and range expansion of ixodes scapularis ticks and of borrelia burgdorferi and anaplasma phagocytophilum in canada. | during the spring in 2005 and 2006, 39,095 northward-migrating land birds were captured at 12 bird observatories in eastern canada to investigate the role of migratory birds in northward range expansion of lyme borreliosis, human granulocytic anaplasmosis, and their tick vector, ixodes scapularis. the prevalence of birds carrying i. scapularis ticks (mostly nymphs) was 0.35% (95% confidence interval [ci] = 0.30 to 0.42), but a nested study by experienced observers suggested a more realistic infe ... | 2008 | 18245258 |
| a tightly regulated surface protein of borrelia burgdorferi is not essential to the mouse-tick infectious cycle. | borrelia burgdorferi synthesizes a variety of differentially regulated outer surface lipoproteins in the tick vector and in vertebrate hosts. among these is ospd, a protein that is highly induced in vitro by conditions that mimic the tick environment. using genetically engineered strains in which ospd is deleted, we demonstrate that this protein is not required for b. burgdorferi survival and infectivity in either the mouse or the tick. however, examination of both transcript levels and protein ... | 2008 | 18332210 |
| a possible canine tick-bite reaction to ixodes muris. | an airedale terrier became acutely ill following attachment of an ixodes muris tick. clinical signs waned within hours of tick removal, similar to a pattern previously documented in animals harboring i. muris. this supports the theory that i. muris can induce a noninfectious, severe inflammatory reaction in domestic animals. | 2008 | 18390101 |
| bb0323 function is essential for borrelia burgdorferi virulence and persistence through tick-rodent transmission cycle. | borrelia burgdorferi bb0323 encodes an immunogenic protein in mammalian hosts, including humans. an analysis of bb0323 expression in vivo showed variable transcription throughout the spirochete infection cycle, with elevated expression during tick-mouse transmission. deletion of bb0323 in infectious b. burgdorferi did not affect microbial survival in vitro, despite considerable alterations in growth kinetics and cell morphology. the bb0323 mutants were unable to infect either mice or ticks and w ... | 2009 | 19754308 |
| use of the cre-lox recombination system to investigate the lp54 gene requirement in the infectious cycle of borrelia burgdorferi. | borrelia burgdorferi, the causative agent of lyme disease, has a complex genome consisting of a linear chromosome and up to 21 linear and circular plasmids. these plasmids encode numerous proteins critical to the spirochete's infectious cycle and many hypothetical proteins whose functions and requirements are unknown. the conserved linear plasmid lp54 encodes several proteins important for survival in the mouse-tick infectious cycle, but the majority of the proteins are of unknown function and l ... | 2010 | 20231410 |
| detection of lyme disease spirochete, borrelia burgdorferi sensu lato, including three novel genotypes in ticks (acari: ixodidae) collected from songbirds (passeriformes) across canada. | lyme disease is reported across canada, but pinpointing the source of infection has been problematic. in this three-year, bird-tick-pathogen study (2004-2006), 366 ticks representing 12 species were collected from 151 songbirds (31 passerine species/subspecies) at 16 locations canada-wide. of the 167 ticks/pools tested, 19 (11.4%) were infected with borrelia burgdorferi sensu lato (s.l.). sequencing of the rrf-rrl intergenic spacer gene revealed four borrelia genotypes: b. burgdorferi sensu stri ... | 2010 | 20618658 |
| bb0844, an rpos-regulated protein, is dispensable for borrelia burgdorferi infectivity and maintenance in the mouse-tick infectious cycle. | the genome of borrelia burgdorferi, the causative agent of lyme disease, is comprised of a large linear chromosome and numerous smaller linear and circular plasmids. b. burgdorferi exhibits substantial genomic variation, and previous studies revealed genotype-specific variation at the right chromosomal telomere. a correlation has also been established between genotype and invasiveness. the correlation between chromosome length and genotype and between genotype and invasiveness suggested that a g ... | 2010 | 21173312 |
| analysis of the borrelia burgdorferi cyclic-di-gmp-binding protein plza reveals a role in motility and virulence. | the cyclic-dimeric-gmp (c-di-gmp)-binding protein pilz has been implicated in bacterial motility and pathogenesis. although bb0733 (plza), the only pilz domain-containing protein in borrelia burgdorferi, was reported to bind c-di-gmp, neither its role in motility or virulence nor it's affinity for c-di-gmp has been reported. we determined that plza specifically binds c-di-gmp with high affinity (dissociation constant [k(d)], 1.25 µm), consistent with k(d) values reported for c-di-gmp-binding pro ... | 2011 | 21357718 |
| borrelia burgdorferi linear plasmid 38 is dispensable for completion of the mouse-tick infectious cycle. | borrelia burgdorferi, the causative agent of lyme disease, exists in a complex enzootic cycle, transiting between its vector, ixodes ticks, and a diverse range of vertebrate hosts. b. burgdorferi linear plasmid 38 (lp38) contains several genes that are differentially regulated in response to conditions mimicking the tick or mouse environments, suggesting that these plasmid-borne genes may encode proteins important for the b. burgdorferi infectious cycle. some of these genes encode potential viru ... | 2011 | 21708994 |
| single-tube real-time pcr assay for differentiation of ixodes affinis and ixodes scapularis. | ixodes affinis neumann (1899) and ixodes scapularis say (1821) are tick vectors of the etiologic agent of lyme disease, borrelia burgdorferi sensu stricto. ixodes affinis and i. scapularis are morphologically very similar, and as they are sympatric in the mid- and south-atlantic u.s. coastal states, their accurate identification is crucial to studies of disease and vector ecology in this area. this work describes a rapid, single-tube sybr(®) green-based real-time pcr assay for differentiation of ... | 2013 | 24192510 |
| borrelia burgdorferi linear plasmid 28-3 confers a selective advantage in an experimental mouse-tick infection model. | borrelia burgdorferi, the bacterium that causes lyme disease, has a unique segmented genome consisting of numerous linear and circular plasmids and a linear chromosome. many of these genetic elements have been found to encode factors critical for b. burgdorferi to complete the infectious cycle. however, several plasmids remain poorly characterized, and their roles during infection with b. burgdorferi have not been elucidated. to more fully characterize the role of one of the four 28-kb linear pl ... | 2013 | 23753630 |
| borrelia burgdorferi bba66 gene inactivation results in attenuated mouse infection by tick transmission. | the impact of the borrelia burgdorferi surface-localized immunogenic lipoprotein bba66 on vector and host infection was evaluated by inactivating the encoding gene, bba66, and characterizing the mutant phenotype throughout the natural mouse-tick-mouse cycle. the bba66-deficient mutant isolate, bb(δa66), remained infectious in mice by needle inoculation of cultured organisms, but differences in spirochete burden and pathology in the tibiotarsal joint were observed relative to the parental wild-ty ... | 2013 | 23630963 |
| population-based passive tick surveillance and detection of expanding foci of blacklegged ticks ixodes scapularis and the lyme disease agent borrelia burgdorferi in ontario, canada. | we identified ticks submitted by the public from 2008 through 2012 in ontario, canada, and tested blacklegged ticks ixodes scapularis for borrelia burgdorferi and anaplasma phagocytophilum. among the 18 species of ticks identified, i. scapularis, dermacentor variabilis, ixodes cookei and amblyomma americanum represented 98.1% of the 14,369 ticks submitted. rates of blacklegged tick submission per 100,000 population were highest in ontario's eastern region; d. variabilis in central west and easte ... | 2014 | 25171252 |
| climate change and habitat fragmentation drive the occurrence of borrelia burgdorferi, the agent of lyme disease, at the northeastern limit of its distribution. | lyme borreliosis is rapidly emerging in canada, and climate change is likely a key driver of the northern spread of the disease in north america. we used field and modeling approaches to predict the risk of occurrence of borrelia burgdorferi, the bacteria causing lyme disease in north america. we combined climatic and landscape variables to model the current and future (2050) potential distribution of the black-legged tick and the white-footed mouse at the northeastern range limit of lyme diseas ... | 2014 | 25469157 |
| regulatory protein bbd18 of the lyme disease spirochete: essential role during tick acquisition? | the lyme disease spirochete borrelia burgdorferi senses and responds to environmental cues as it transits between the tick vector and vertebrate host. failure to properly adapt can block transmission of the spirochete and persistence in either vector or host. we previously identified bbd18, a novel plasmid-encoded protein of b. burgdorferi, as a putative repressor of the host-essential factor ospc. in this study, we investigate the in vivo role of bbd18 as a regulatory protein, using an experime ... | 2014 | 24692636 |
| long-term survival of borrelia burgdorferi lacking the hibernation promotion factor homolog in the unfed tick vector. | borrelia burgdorferi, a causative agent of lyme borreliosis, is a zoonotic pathogen that survives in nutrient-limited environments within a tick, prior to transmission to its mammalian host. survival under these prolonged nutrient-limited conditions is thought to be similar to survival during stationary phase, which is characterized by growth cessation and decreased protein production. multiple ribosome-associated proteins are implicated in stationary-phase survival of escherichia coli. these pr ... | 2015 | 26438790 |
| borrelia burgdorferi elongation factor ef-tu is an immunogenic protein during lyme borreliosis. | borrelia burgdorferi, the etiological agent of lyme disease, does not produce lipopolysaccharide but expresses a large number of lipoproteins on its cell surface. these outer membrane lipoproteins are highly immunogenic and have been used for serodiagnosis of lyme disease. recent studies have shown that highly conserved cytosolic proteins such as enolase and elongation factor tu (ef-tu) unexpectedly localized on the surface of bacteria including b. burgdorferi, and surface-localized enolase has ... | 2015 | 26954993 |
| different ecological niches for ticks of public health significance in canada. | tick-borne diseases are a growing public health concern as their incidence and range have increased in recent decades. lyme disease is an emerging infectious disease in canada due to northward expansion of the geographic range of ixodes scapularis, the principal tick vector for the lyme disease agent borrelia burgdorferi, into central and eastern canada. in this study the geographical distributions of ixodid ticks, including i. scapularis, and environmental factors associated with their occurren ... | 2015 | 26131550 |
| use of an endogenous plasmid locus for stable in trans complementation in borrelia burgdorferi. | targeted mutagenesis and complementation are important tools for studying genes of unknown function in the lyme disease spirochete borrelia burgdorferi. a standard method of complementation is reintroduction of a wild-type copy of the targeted gene on a shuttle vector. however, shuttle vectors are present at higher copy numbers than b. burgdorferi plasmids and are potentially unstable in the absence of selection, thereby complicating analyses in the mouse-tick infectious cycle. b. burgdorferi ha ... | 2015 | 25452278 |
| babesia microti from humans and ticks hold a genomic signature of strong population structure in the united states. | babesia microti is an emerging tick-borne apicomplexan parasite with increasing geographic range and incidence in the united states. the rapid expansion of b. microti into its current distribution in the northeastern usa has been due to the range expansion of the tick vector, ixodes scapularis, upon which the causative agent is dependent for transmission to humans. | 2016 | 27821055 |
| borrelia burgdorferi ched promotes various functions in chemotaxis and the pathogenic life cycle of the spirochete. | borrelia burgdorferi possesses a sophisticated chemotaxis signaling system; however, the roles of the majority of the chemotaxis proteins in the infectious life cycle have not yet been demonstrated. specifically, the role of ched during host colonization has not been demonstrated in any bacterium. here, we systematically characterized the b. burgdorferi ched homolog using genetics and biochemical and mouse-tick-mouse infection cycle studies. bacillus subtilis ched plays an important role in chem ... | 2016 | 27021244 |
| functional equivalence of ospa and ospb, but not ospc, in tick colonization by borrelia burgdorferi. | borrelia burgdorferi, a lyme disease agent, makes different major outer surface lipoproteins at different stages of its mouse-tick infectious cycle. outer surface protein a (ospa) coats the spirochetes from the time they enter ticks until they are transmitted to a mammal. ospa is required for normal tick colonization and has been shown to bind a tick midgut protein, indicating that ospa may serve as a tick midgut adhesin. tick colonization by spirochetes lacking ospa is increased when the infect ... | 2016 | 26953324 |
| function of the borrelia burgdorferi ftsh homolog is essential for viability both in vitro and in vivo and independent of hflk/c. | in many bacteria, the ftsh protease and its modulators, hflk and hflc, form a large protein complex that contributes to both membrane protein quality control and regulation of the cellular response to environmental stress. both activities are crucial to the lyme disease pathogen borrelia burgdorferi, which depends on membrane functions, such as motility, protein transport, and cell signaling, to respond to rapid changes in its environment. using an inducible system, we demonstrate that ftsh prod ... | 2016 | 27094329 |
| motility is crucial for the infectious life cycle of borrelia burgdorferi. | the lyme disease spirochete, borrelia burgdorferi, exists in a zoonotic cycle involving an arthropod tick and mammalian host. dissemination of the organism within and between these hosts depends upon the spirochete's ability to traverse through complex tissues. additionally, the spirochete outruns the host immune cells while migrating through the dermis, suggesting the importance of b. burgdorferi motility in evading host clearance. b. burgdorferi's periplasmic flagellar filaments are composed p ... | 2013 | 23529620 |