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Franzrainer Matuschka - One of the best experts on this subject based on the ideXlab platform.
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absence of lyme disease Spirochetes in larval ixodes ricinus ticks
Vector-borne and Zoonotic Diseases, 2012Co-Authors: Dania Richter, Alina Debski, Zdenek Hubalek, Franzrainer MatuschkaAbstract:Abstract To determine which kind of Spirochete infects larval Ixodes ricinus, we examined questing larvae and larvae derived from engorged females for the presence of particular spirochetal DNA that permitted species differentiation. Borrelia miyamotoi was the sole Spirochete detected in larval ticks sampled while questing on vegetation. Questing nymphal and adult ticks were infected mainly by Borrelia afzelii, whereas larval ticks resulting from engorged females of the same population were solely infected by B. miyamotoi. Since larvae acquire Lyme disease Spirochetes within a few hours of attachment to an infected rodent, questing larvae in nature may have acquired Lyme disease Spirochetes from an interrupted host contact. Even if transovarial transmission of Lyme disease Spirochetes may occasionally occur, it seems to be an exceedingly rare event. No undisputable proof exists for vertical transmission of Lyme disease Spirochetes, whereas B. miyamotoi appears to be readily passed between generations of v...
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Absence of Lyme disease Spirochetes in larval Ixodes ricinus ticks.
Vector borne and zoonotic diseases (Larchmont N.Y.), 2011Co-Authors: Dania Richter, Alina Debski, Zdenek Hubalek, Franzrainer MatuschkaAbstract:Abstract To determine which kind of Spirochete infects larval Ixodes ricinus, we examined questing larvae and larvae derived from engorged females for the presence of particular spirochetal DNA that permitted species differentiation. Borrelia miyamotoi was the sole Spirochete detected in larval ticks sampled while questing on vegetation. Questing nymphal and adult ticks were infected mainly by Borrelia afzelii, whereas larval ticks resulting from engorged females of the same population were solely infected by B. miyamotoi. Since larvae acquire Lyme disease Spirochetes within a few hours of attachment to an infected rodent, questing larvae in nature may have acquired Lyme disease Spirochetes from an interrupted host contact. Even if transovarial transmission of Lyme disease Spirochetes may occasionally occur, it seems to be an exceedingly rare event. No undisputable proof exists for vertical transmission of Lyme disease Spirochetes, whereas B. miyamotoi appears to be readily passed between generations of v...
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differential risk for lyme disease along hiking trail germany
Emerging Infectious Diseases, 2011Co-Authors: Dania Richter, Franzrainer MatuschkaAbstract:To estimate relative risk for exposure to ticks infected with Lyme disease–causing Spirochetes in different land-use types along a trail in Germany, we compared tick density and Spirochete prevalence on ruminant pasture with that on meadow and fallow land. Risk was significantly lower on pasture than on meadow and fallow land.
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Perpetuation of the Lyme disease Spirochete Borrelia lusitaniae by lizards.
Applied and environmental microbiology, 2006Co-Authors: Dania Richter, Franzrainer MatuschkaAbstract:To determine whether the Lyme disease Spirochete Borrelia lusitaniae is associated with lizards, we compared the prevalence and genospecies of Spirochetes present in rodent- and lizard-associated ticks at a site where this Spirochete frequently infects questing ticks. Whereas questing nymphal Ixodes ricinus ticks were infected mainly by Borrelia afzelii, one-half of the infected adult ticks harbored B. lusitaniae at our study site. Lyme disease Spirochetes were more prevalent in sand lizards (Lacerta agilis) and common wall lizards (Podarcis muralis) than in small rodents. Although subadult ticks feeding on rodents acquired mainly B. afzelii, subadult ticks feeding on lizards became infected by B. lusitaniae. Genetic analysis confirmed that the Spirochetes isolated from ticks feeding on lizards are members of the B. lusitaniae genospecies and resemble type strain PotiB2. At our central European study site, lizards, which were previously considered zooprophylactic for the agent of Lyme disease, appear to perpetuate B. lusitaniae.
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relationships of a novel lyme disease Spirochete borrelia spielmani sp nov with its hosts in central europe
Applied and Environmental Microbiology, 2004Co-Authors: Dania Richter, Daniela B Schlee, Rainer Allgower, Franzrainer MatuschkaAbstract:To determine whether the pathogenic variant of Lyme disease Spirochetes, isolate A14S, is perpetuated in a particular reservoir-vector relationship, we screened vector ticks in various Central European sites for a related Spirochete and determined its host association. A14S-like Spirochetes infect numerous questing ticks in the Petite Camargue Alsacienne (PC). They frequently infect dormice, but no mice or voles. Garden dormice appear to be better reservoir hosts for A14S-like Spirochetes than for Borrelia afzelii, because these Spirochetes are retained longer and infect ticks more readily. Spirochetes associated with garden dormice in the PC site form a homologous entity with those isolated from a human patient in The Netherlands. Its unique biological relationship together with previous genetic characterization justifies designating this dormouse-associated genospecies as a distinct entity. Garden dormice serve as the main reservoir hosts of a novel genospecies, Borrelia spielmani sp. nov., one of several that cause Lyme disease in people.
Dania Richter - One of the best experts on this subject based on the ideXlab platform.
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absence of lyme disease Spirochetes in larval ixodes ricinus ticks
Vector-borne and Zoonotic Diseases, 2012Co-Authors: Dania Richter, Alina Debski, Zdenek Hubalek, Franzrainer MatuschkaAbstract:Abstract To determine which kind of Spirochete infects larval Ixodes ricinus, we examined questing larvae and larvae derived from engorged females for the presence of particular spirochetal DNA that permitted species differentiation. Borrelia miyamotoi was the sole Spirochete detected in larval ticks sampled while questing on vegetation. Questing nymphal and adult ticks were infected mainly by Borrelia afzelii, whereas larval ticks resulting from engorged females of the same population were solely infected by B. miyamotoi. Since larvae acquire Lyme disease Spirochetes within a few hours of attachment to an infected rodent, questing larvae in nature may have acquired Lyme disease Spirochetes from an interrupted host contact. Even if transovarial transmission of Lyme disease Spirochetes may occasionally occur, it seems to be an exceedingly rare event. No undisputable proof exists for vertical transmission of Lyme disease Spirochetes, whereas B. miyamotoi appears to be readily passed between generations of v...
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Absence of Lyme disease Spirochetes in larval Ixodes ricinus ticks.
Vector borne and zoonotic diseases (Larchmont N.Y.), 2011Co-Authors: Dania Richter, Alina Debski, Zdenek Hubalek, Franzrainer MatuschkaAbstract:Abstract To determine which kind of Spirochete infects larval Ixodes ricinus, we examined questing larvae and larvae derived from engorged females for the presence of particular spirochetal DNA that permitted species differentiation. Borrelia miyamotoi was the sole Spirochete detected in larval ticks sampled while questing on vegetation. Questing nymphal and adult ticks were infected mainly by Borrelia afzelii, whereas larval ticks resulting from engorged females of the same population were solely infected by B. miyamotoi. Since larvae acquire Lyme disease Spirochetes within a few hours of attachment to an infected rodent, questing larvae in nature may have acquired Lyme disease Spirochetes from an interrupted host contact. Even if transovarial transmission of Lyme disease Spirochetes may occasionally occur, it seems to be an exceedingly rare event. No undisputable proof exists for vertical transmission of Lyme disease Spirochetes, whereas B. miyamotoi appears to be readily passed between generations of v...
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differential risk for lyme disease along hiking trail germany
Emerging Infectious Diseases, 2011Co-Authors: Dania Richter, Franzrainer MatuschkaAbstract:To estimate relative risk for exposure to ticks infected with Lyme disease–causing Spirochetes in different land-use types along a trail in Germany, we compared tick density and Spirochete prevalence on ruminant pasture with that on meadow and fallow land. Risk was significantly lower on pasture than on meadow and fallow land.
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Perpetuation of the Lyme disease Spirochete Borrelia lusitaniae by lizards.
Applied and environmental microbiology, 2006Co-Authors: Dania Richter, Franzrainer MatuschkaAbstract:To determine whether the Lyme disease Spirochete Borrelia lusitaniae is associated with lizards, we compared the prevalence and genospecies of Spirochetes present in rodent- and lizard-associated ticks at a site where this Spirochete frequently infects questing ticks. Whereas questing nymphal Ixodes ricinus ticks were infected mainly by Borrelia afzelii, one-half of the infected adult ticks harbored B. lusitaniae at our study site. Lyme disease Spirochetes were more prevalent in sand lizards (Lacerta agilis) and common wall lizards (Podarcis muralis) than in small rodents. Although subadult ticks feeding on rodents acquired mainly B. afzelii, subadult ticks feeding on lizards became infected by B. lusitaniae. Genetic analysis confirmed that the Spirochetes isolated from ticks feeding on lizards are members of the B. lusitaniae genospecies and resemble type strain PotiB2. At our central European study site, lizards, which were previously considered zooprophylactic for the agent of Lyme disease, appear to perpetuate B. lusitaniae.
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relationships of a novel lyme disease Spirochete borrelia spielmani sp nov with its hosts in central europe
Applied and Environmental Microbiology, 2004Co-Authors: Dania Richter, Daniela B Schlee, Rainer Allgower, Franzrainer MatuschkaAbstract:To determine whether the pathogenic variant of Lyme disease Spirochetes, isolate A14S, is perpetuated in a particular reservoir-vector relationship, we screened vector ticks in various Central European sites for a related Spirochete and determined its host association. A14S-like Spirochetes infect numerous questing ticks in the Petite Camargue Alsacienne (PC). They frequently infect dormice, but no mice or voles. Garden dormice appear to be better reservoir hosts for A14S-like Spirochetes than for Borrelia afzelii, because these Spirochetes are retained longer and infect ticks more readily. Spirochetes associated with garden dormice in the PC site form a homologous entity with those isolated from a human patient in The Netherlands. Its unique biological relationship together with previous genetic characterization justifies designating this dormouse-associated genospecies as a distinct entity. Garden dormice serve as the main reservoir hosts of a novel genospecies, Borrelia spielmani sp. nov., one of several that cause Lyme disease in people.
Tom G. Schwan - One of the best experts on this subject based on the ideXlab platform.
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colony formation in solid medium by the relapsing fever Spirochetes borrelia hermsii and borrelia turicatae
Ticks and Tick-borne Diseases, 2017Co-Authors: Sandra J. Raffel, Tom G. Schwan, Brandi N Williamson, Frank C GherardiniAbstract:Abstract Relapsing fever (RF) in North America is caused primarily by the Spirochete Borrelia hermsii and is associated with the bite of its tick vector Ornithodoros hermsi. Although this Spirochete was known long before the discovery of the Lyme disease (LD) Spirochete, Borrelia burgdorferi, basic methods to facilitate the study of B. hermsii have lagged behind. One important technique to expedite the study of the molecular biology and pathogenesis of B. hermsii would be a reliable method to grow and clone these bacteria in solid medium, which we now describe. We have defined the solidifying agent, plating temperature, oxygen concentration, and pH for the efficient plating of two species of RF Spirochetes, B. hermsii and Borrelia turicatae. Importantly, this technique allowed us to successfully isolate virulent, clonal cell lines of Spirochetes, and to enumerate and isolate viable B. hermsii from infected mouse blood and tick tissues. Our results also demonstrate the value of testing a range of several environmental variables to increase the efficiency of bacterial isolation, which may be helpful for researchers working on other prokaryotes that are intractable for in vitro growth.
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inactivation of genes for antigenic variation in the relapsing fever Spirochete borrelia hermsii reduces infectivity in mice and transmission by ticks
PLOS Pathogens, 2014Co-Authors: Sandra J. Raffel, Robert J. Fischer, James M Battisti, Tom G. SchwanAbstract:Borrelia hermsii, a causative agent of relapsing fever of humans in western North America, is maintained in enzootic cycles that include small mammals and the tick vector Ornithodoros hermsi. In mammals, the Spirochetes repeatedly evade the host’s acquired immune response by undergoing antigenic variation of the variable major proteins (Vmps) produced on their outer surface. This mechanism prolongs Spirochete circulation in blood, which increases the potential for acquisition by fast-feeding ticks and therefore perpetuation of the Spirochete in nature. Antigenic variation also underlies the relapsing disease observed when humans are infected. However, most Spirochetes switch off the bloodstream Vmp and produce a different outer surface protein, the variable tick protein (Vtp), during persistent infection in the tick salivary glands. Thus the production of Vmps in mammalian blood versus Vtp in ticks is a dominant feature of the Spirochete’s alternating life cycle. We constructed two mutants, one which was unable to produce a Vmp and the other was unable to produce Vtp. The mutant lacking a Vmp constitutively produced Vtp, was attenuated in mice, produced lower cell densities in blood, and was unable to relapse in animals after its initial Spirochetemia. This mutant also colonized ticks and was infectious by tick-bite, but remained attenuated compared to wild-type and reconstituted Spirochetes. The mutant lacking Vtp also colonized ticks but produced neither Vtp nor a Vmp in tick salivary glands, which rendered the Spirochete noninfectious by tick bite. Thus the ability of B. hermsii to produce Vmps prolonged its survival in blood, while the synthesis of Vtp was essential for mammalian infection by the bite of its tick vector.
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first isolation of the relapsing fever Spirochete borrelia hermsii from a domestic dog
Ticks and Tick-borne Diseases, 2014Co-Authors: Ashley L Kelly, Robert J. Fischer, Sandra J. Raffel, Michael Bellinghausen, Connie Stevenson, Tom G. SchwanAbstract:In North America, tick-borne relapsing fever of humans is most frequently caused by infection with the Spirochete Borrelia hermsii. Prior to our investigation, this Spirochete was not known to infect dogs although another species, Borrelia turicatae, has been isolated from domestic canids in Florida and Texas. A clinically ill dog in Washington, USA, was Spirochetemic upon examination. Spirochetes were isolated from the dog's serum and examined by PCR and multi-locus sequence typing. DNA sequences for 7 loci all typed the Spirochete as B. hermsii and a member of genomic group II of this species. Therefore, companion dogs that reside in rustic cabins in higher elevation forests are at risk of infection with B. hermsii.
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Borrelia hermsii Acquisition Order in Superinfected Ticks Determines Transmission Efficiency
Infection and immunity, 2013Co-Authors: Paul F. Policastro, Sandra J. Raffel, Tom G. SchwanAbstract:ABSTRACT Multilocus sequence typing of Borrelia hermsii isolates reveals its divergence into two major genomic groups (GG), but no differences in transmission efficiency or host pathogenicity are associated with these genotypes. To compare GGI and GGII in the tick-host infection cycle, we first determined if Spirochetes from the two groups could superinfect the tick vector Ornithodoros hermsi. We infected mice with isolates from each group and fed ticks sequentially on these mice. We then fed the infected ticks on naive mice and measured GGI and GGII Spirochete densities in vector and host, using quantitative PCR of genotype-specific chromosomal DNA sequences. Sequential feedings resulted in dual tick infections, showing that GGI or GGII primary acquisition did not block superinfection by a secondary agent. On transmission to naive mice at short intervals after acquisition, ticks with primary GGI and secondary GGII Spirochete infections caused mixed GGI and GGII infections in mice. However, ticks with primary GGII and secondary GGI Spirochete infections caused only GGII infections with all isolate pairs examined. At longer intervals after acquisition, the exclusion of GGI by GGII Spirochetes declined and cotransmission predominated. We then examined GGI and GGII Spirochetemia in mice following single inoculation and coinoculation by needle and found that GGI Spirochete densities were reduced on multiple days when coinoculated with GGII. These findings indicate that dual GGI-GGII Spirochete infections can persist in ticks and that transmission to a vertebrate host is dependent on the order of tick acquisition and the interval between acquisition and transmission events.
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Acquisition and subsequent transmission of Borrelia hermsii by the soft tick Ornithodoros hermsi.
Journal of medical entomology, 2011Co-Authors: Job E Lopez, Brandi N. Mccoy, Benjamin J. Krajacich, Tom G. SchwanAbstract:Tick-borne relapsing fever is caused by Spirochetes within the genus Borrelia. The hallmark of this disease is recurrent febrile episodes and high Spirochete densities in mammalian blood resulting from immune evasion. Between episodes of Spirochetemia when bacterial densities are low, it is unknown whether ticks can acquire the Spirochetes, become colonized by the bacteria, and subsequently transmit the bacteria once they feed again. We addressed these questions by feeding ticks, Ornithodoros hermsi Wheeler (Acari: Argasidae), daily on an infected mouse during low and high levels of Spirochete infections. This study demonstrates that Spirochete acquisition by the tick vector can occur during low levels of mammalian infection and that once a Spirochetemic threshold is attained within the blood, nearly 100% of ticks become colonized by Borrelia hermsii.
Helmut König - One of the best experts on this subject based on the ideXlab platform.
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phylogenetic analysis and in situ identification of uncultivated Spirochetes from the hindgut of the termite mastotermes darwiniensis
Systematic and Applied Microbiology, 1996Co-Authors: Manfred Berchtold, Helmut KönigAbstract:Summary Different small subunit ribosomal DNA (SSU rDNA) sequences of uncultivated Spirochetes from the hindgut of the termite Mastotermes darwiniensis were determined and phylogenetically analysed. Starting with DNA isolated from hindgut contents we amplified SSU rDNA coding regions by PCR using bacteria- and Spirochete-specific primers, respectively. Cloning and sequencing of the amplification products re-sulted in 11 different spirochetal SSU rDNA sequences with similarity values of 81.8% to 99.0% to each other. Phylogenetic trees showed that the obtained sequences are related to the genus Treponema with 84.0% to 91.1% similarity to Treponema spec. H1 and Spirochaeta stenostrepta as their nearest relatives among the cultivated Spirochetes. Using fluorescence in situ hybridisation one of the SSU rDNA sequences could be assigned to a large Spirochete. So at least one of the large hindgut Spirochetes unique in termite hindguts and assigned to the genera Hollandina , Pillotina , Clevelandina or Diplocalyx phylogenetically belongs to the treponeme cluster of Spirochetes.
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16s rdna sequence and phylogenetic position of an uncultivated Spirochete from the hindgut of the termite mastotermes darwiniensis froggatt
Fems Microbiology Letters, 1994Co-Authors: Manfred Berchtold, Wolfgang Ludwig, Helmut KönigAbstract:We have analyzed the 16S rDNA sequence and the phylogenetic position of an uncultivated Spirochete from the hindgut contents of the Australian termite Mastotermes darwiniensis Froggatt. The 16S rRNA genes of bacteria from the hindgut contents of Mastotermes darwiniensis were amplified by polymerase chain reaction. The amplification products were cloned and sequenced. The sequences were compared to known homologous primary structures. Two of the clones (MDS1 and MDS3) had an insert of 1498 nucleotides showing typical signatures of Spirochete 16S rRNA sequences. The sequences of the two clones were most similar to the 16S rRNA sequence of Spirochaeta stenostrepta (89.8%) and Treponema sp. strain H1 (90.7%). Phylogenetical analysis positioned the hindgut Spirochete sequence with that of the free-living anaerobic Spirochaeta stenostrepta and Treponema sp. strain H1 as its nearest relatives within the cluster of the Spirochetes. We conclude that the analyzed SSU rDNA sequences originate from a Spirochete related to the genus Treponema. It is possibly one of the uncultivated unique Spirochetes symbiotic in termite hindguts.
Jean I. Tsao - One of the best experts on this subject based on the ideXlab platform.
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reviewing molecular adaptations of lyme borreliosis Spirochetes in the context of reproductive fitness in natural transmission cycles
Veterinary Research, 2009Co-Authors: Jean I. TsaoAbstract:Lyme borreliosis (LB) is caused by a group of pathogenic Spirochetes - most often Borrelia burgdorferi, B. afzelii, and B. garinii - that are vectored by hard ticks in the Ixodes ricinus-persulcatus complex, which feed on a variety of mammals, birds, and lizards. Although LB is one of the best-studied vector-borne zoonoses, the annual incidence in North America and Europe leads other vector-borne diseases and continues to increase. What factors make the LB system so successful, and how can researchers hope to reduce disease risk - either through vaccinating humans or reducing the risk of contacting infected ticks in nature? Discoveries of molecular interactions involved in the transmission of LB Spirochetes have accelerated recently, revealing complex interactions among the Spirochete-tick-vertebrate triad. These interactions involve multiple, and often redundant, pathways that reflect the evolution of general and specific mechanisms by which the Spirochetes survive and reproduce. Previous reviews have focused on the molecular interactions or population biology of the system. Here molecular interactions among the LB Spirochete, its vector, and vertebrate hosts are reviewed in the context of natural maintenance cycles, which represent the ecological and evolutionary contexts that shape these interactions. This holistic system approach may help researchers develop additional testable hypotheses about transmission processes, interpret laboratory results, and guide development of future LB control measures and management. Lyme borreliosis / R0 / vector-borne / tick
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Reviewing molecular adaptations of Lyme borreliosis Spirochetes in the context of reproductive fitness in natural transmission cycles
Veterinary Research, 2009Co-Authors: Jean I. TsaoAbstract:Lyme borreliosis (LB) is caused by a group of pathogenic Spirochetes - most often Borrelia burgdorferi, B. afzelii, and B. garinii - that are vectored by hard ticks in the Ixodes ricinus-persulcatus complex, which feed on a variety of mammals, birds, and lizards. Although LB is one of the best-studied vector-borne zoonoses, the annual incidence in North America and Europe leads other vector-borne diseases and continues to increase. What factors make the LB system so successful, and how can researchers hope to reduce disease risk - either through vaccinating humans or reducing the risk of contacting infected ticks in nature? Discoveries of molecular interactions involved in the transmission of LB Spirochetes have accelerated recently, revealing complex interactions among the Spirochete-tick-vertebrate triad. These interactions involve multiple, and often redundant, pathways that reflect the evolution of general and specific mechanisms by which the Spirochetes survive and reproduce. Previous reviews have focused on the molecular interactions or population biology of the system. Here molecular interactions among the LB Spirochete, its vector, and vertebrate hosts are reviewed in the context of natural maintenance cycles, which represent the ecological and evolutionary contexts that shape these interactions. This holistic system approach may help researchers develop additional testable hypotheses about transmission processes, interpret laboratory results, and guide development of future LB control measures and management.
