SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "L773:0095 1137 ;pers:(Bergström Sven)"

Sökning: L773:0095 1137 > Bergström Sven

  • Resultat 1-7 av 7
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Bunikis, J, et al. (författare)
  • Molecular polymorphism of the Lyme disease agent Borrelia garinii in northern Europe is influenced by a novel enzootic Borrelia focus in the North Atlantic
  • 1996
  • Ingår i: Journal of Clinical Microbiology. - Washington, DC, United States : American Society for Microbiology. - 0095-1137 .- 1098-660X. ; 34:2, s. 364-368
  • Tidskriftsartikel (refereegranskat)abstract
    • Lyme disease Borrelia species are distributed in temperate areas of North America and Eurasia. To elucidate the distribution of borreliae in subarctic regions, strains isolated from Ixodes ricinus and Ixodes uriae ticks found on islands in the northern Atlantic and Baltic Sea were molecularly characterized. All isolates were verified as Borrelia garinii by 16S rRNA gene analysis and immunoblotting with monoclonal antibodies specific for the outer surface proteins A and C. Three ribotypes (RTs) of B. garinii were delineated. I. ricinus complex-associated RT1 was phenotypically most heterogeneous. Two newly identified ribotypes were shared by different tick species and conformed to two established OspA serotypes. RT2 was restricted to the islands in the northern Baltic Sea, whereas RT3 was recovered also from ticks found in the North Atlantic. In conclusion, molecular polymorphism of the studied borrelia isolates suggests a complex enzootic potential of B. garinii in northern Europe and implies a novel, seabird tick I. uriae-associated enzootic focus of Lyme disease borreliae in the North Atlantic. 
  •  
2.
  • Gylfe, Åsa, et al. (författare)
  • Isolation of Lyme disease Borrelia from puffins (Fratercula arctica) and seabird ticks (Ixodes uriae) on the Faeroe Islands
  • 1999
  • Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 37:4, s. 890-896
  • Tidskriftsartikel (refereegranskat)abstract
    • This is the first report on the isolation of Lyme disease Borrelia from seabirds on the Faeroe Islands and the characteristics of its enzootic cycle. The major components of the Borrelia cycle include the puffin (Fratercula arctica) as the reservoir and Ixodes uriae as the vector. The importance of this cycle and its impact on the spread of human Lyme borreliosis have not yet been established. Borrelia spirochetes isolated from 2 of 102 sampled puffins were compared to the borreliae previously obtained from seabird ticks, I. uriae. The rrf-rrl intergenic spacer and the rrs and the ospC genes were sequenced and a series of phylogenetic trees were constructed. Sequence data and restriction fragment length polymorphism analysis grouped the strains together with Borrelia garinii. In a seroepidemiological survey performed with residents involved in puffin hunting on the Faeroe Islands, 3 of 81 serum samples were found to be positive by two commonly used clinical tests: a flagellin-based enzyme-linked immunosorbent assay (ELISA) and Western blotting. These three positive serum samples also had high optical density values in a whole-cell ELISA. The finding of seropositive Faeroe Islanders who are regularly exposed to I. uriae indicate that there may be a transfer of B. garinii by this tick species to humans.
  •  
3.
  • Olsen, Björn, et al. (författare)
  • Transhemispheric exchange of Lyme disease spirochetes by seabirds
  • 1995
  • Ingår i: Journal of Clinical Microbiology. - Washington, DC, United States : American Society for Microbiology. - 0095-1137 .- 1098-660X. ; 33:12, s. 3270-3274
  • Tidskriftsartikel (refereegranskat)abstract
    • Lyme disease is a zoonosis transmitted by ticks and caused by the spirochete Borrelia burgdorferi sensu lato. Epidemiological and ecological investigations to date have focused on the terrestrial forms of Lyme disease. Here we show a significant role for seabirds in a global transmission cycle by demonstrating the presence of Lyme disease Borrelia spirochetes in Ixodes uriae ticks from several seabird colonies in both the Southern and Northern Hemispheres. Borrelia DNA was isolated from I. uriae ticks and from cultured spirochetes. Sequence analysis of a conserved region of the flagellin (fla) gene revealed that the DNA obtained was from B. garinii regardless of the geographical origin of the sample. Identical fla gene fragments in ticks obtained from different hemispheres indicate a transhemispheric exchange of Lyme disease spirochetes. A marine ecological niche and a marine epidemiological route for Lyme disease borreliae are proposed. 
  •  
4.
  • Shoberg, Russel J., et al. (författare)
  • Identification of a highly cross-reactive outer surface protein B epitope among diverse geographic isolates of Borrelia spp. causing Lyme disease
  • 1994
  • Ingår i: Journal of Clinical Microbiology. - : American Society for Microbiology (ASM). - 0095-1137 .- 1098-660X. ; 32:2, s. 489-500
  • Tidskriftsartikel (refereegranskat)abstract
    • The outer surface lipoprotein B (OspB) of Borrelia burgdorferi is a major component of the borrelial protein profile and has been shown to be highly immunogenic in experimentally immunized and infected mammals. However, the ospB loci of different strains show considerable heterology at the nucleic acid sequence level, and the progeny of a clonal strain of B. burgdorferi exhibited OspB polymorphisms with respect to apparent molecular weights and reactivities with monoclonal antibodies. These data suggest that OspB is not a good candidate for vaccination or diagnostic purposes. The present study describes a monoclonal antibody, designated 84C, directed against a very highly conserved domain of the OspB lipoprotein. Western immunoblot analysis with 84C demonstrated reactivity in 84.2% of human, tick, and other vertebrate isolate strains examined from widely diverse geographic regions, including strains of B. burgdorferi sensu stricto and two closely related species, B. garinii and B. afzelii. The 84C-binding region was delimited to a highly conserved 11-amino-acid region in the carboxyl terminus of OspB as demonstrated by (i) DNA sequence analysis of wild-type and 84C-resistant mutant ospB alleles and (ii) deletion mutagenesis of a recombinant ospB gene in Escherichia coli. Finally, the 84C epitope was demonstrated to be exposed on the borrelial surface in situ as (i) the monoclonal antibody 84C was able to agglutinate borrelias in culture and (ii) 84C-resistant escape variants were isolated. These data suggest that the potential value of OspB as a vaccine candidate or diagnostic tool be examined more closely, in the context of the 84C-reactive domain.
  •  
5.
  • Toledo-Arana, A, et al. (författare)
  • Phylogenetic analysis of a virulent Borrelia species isolated from patients with relapsing fever
  • 2010
  • Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 48:7, s. 2484-2489
  • Tidskriftsartikel (refereegranskat)abstract
    • Multilocus sequence analysis (MLSA) was used to clarify the taxonomic status of a virulent Borrelia organism previously isolated from patients with relapsing fever and from ticks in Spain that is designated the Spanish relapsing fever (SRF) Borrelia. This species has been used extensively in experimental infection models because of its continued virulence. Seven genes were amplified to analyze the phylogenetic relationships among several Spanish isolates of SRF Borrelia and other relapsing fever Borrelia species. The genes targeted in this study included rrs and flaB, which have commonly been used in phylogenetic studies; the rrf-rrl intergenic spacer (IGS), which is highly discriminatory; and four additional genes, p66, groEL, glpQ, and recC, which are located on the chromosome and which have therefore evolved in a clonal way. The species included in this study were Borrelia duttonii, B. recurrentis, B. crocidurae, and B. hispanica as Old World Borrelia species and B. turicatae and B. hermsii as New World Borrelia species. The results obtained by MLSA of the SRF Borrelia on the basis of 1% of the genomic sequence data analyzed confirmed that the SRF Borrelia isolates are B. hispanica. However, the prototype isolates of B. hispanica used in this study have an uncertain history and display unique phenotypic characteristics that are not shared with the SRF Borrelia. Therefore, we propose to use strain SP1, isolated from a relapsing fever patient in 1994 in southern Spain, as the type strain for B. hispanica.
  •  
6.
  •  
7.
  • Wilhelmsson, Peter, et al. (författare)
  • Prevalence and Diversity of Borrelia Species in Ticks That Have Bitten Humans in Sweden
  • 2010
  • Ingår i: JOURNAL OF CLINICAL MICROBIOLOGY. - : American Society for Microbiology. - 0095-1137 .- 1098-660X. ; 48:11, s. 4169-4176
  • Tidskriftsartikel (refereegranskat)abstract
    • Members of the genus Borrelia are among the most common infectious agents causing tick-borne disease in humans worldwide. Here, we developed a Light Upon eXtension (LUX) real-time PCR assay that can detect and quantify Borrelia species in ticks that have fed on humans, and we applied the assay to 399 such ticks. Borrelia PCR-positive ticks were identified to species level by sequencing the products of conventional PCR performed using Borrelia group-specific primers. There was a 19% prevalence of Borrelia spp. in the detached ticks, and the number of spirochetes per Borrelia PCR-positive tick ranged from 2.0 x 10(2) to 4.9 x 10(5), with a median of 7.8 x 10(3) spirochetes. Adult ticks had a significantly larger number of spirochetes, with a median of 8.4 x 10(4) compared to the median of nymphs of 4.4 x 10(4). Adult ticks also exhibited a higher prevalence of Borrelia (33%) than nymphs (14%). Among the identified species, Borrelia afzelii was found to predominate (61%) and was followed by B. garinii (23%), B. valaisiana (13%), B. burgdorferi sensu stricto (1%), B. lusitaniae (1%), and B. miyamotoi-like (1%). Also, 3% of the ticks were coinfected with multiple strains of B. afzelii. Notably, this is the first report of B. lusitaniae being detected in ticks in Sweden. Our LUX real-time PCR assay proved to be more sensitive than a corresponding TaqMan assay. In conclusion, the novel LUX real-time PCR method is a rapid and sensitive tool for detection and quantification of Borrelia spp. in ticks.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-7 av 7

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy