Most cited papers: Infect Immun. 1988 Aug ;56 (8):1831-6 3397175 [Cited: 103] Changes in infectivity and plasmid profile of the Lyme disease spirochete, Borrelia burgdorferi, as a result of in vitro cultivation. [My paper] T G Schwan , W Burgdorfer , C F Garon In vitro cultivation of Borrelia burgdorferi, the etiologic agent of Lyme spirochetosis, allows for the isolation and growth of this bacterium from infected tissues. However, continuous cultivation in modified Kelly medium causes a reduction in the number of detectable plasmids and the loss of infectivity in the white-footed mouse, Peromyscus leucopus. In an unpassaged culture of B. burgdorferi, nine plasmids were present, including seven linear plasmids ranging in size from 49 to 16 kilobases (kb) and two circular plasmids of 27 and 7.6 kb. The 7.6-kb circular and 22-kb linear plasmids were no longer detectable in spirochetes noninfective in white-footed mice, suggesting that a gene(s) encoding for factors responsible for infection may be present on one or more of these extrachromosomal elements. Furthermore, changes in spirochetal proteins and lipopolysaccharide-like material were observed also during early cultivation and may be related to loss of infectivity. Mesh-terms: Animals; Bacterial Outer Membrane Proteins, analysis; Borrelia burgdorferi; Borrelia, analysis; Borrelia, genetics; Cells, Cultured; DNA, Bacterial, analysis; Lyme Disease, microbiology; Mice; Molecular Weight; Plasmids;
Int J Syst Bacteriol. 1992 Jul ;42:378-83 1380285 [Cited: 100] Delineation of Borrelia burgdorferi sensu stricto, Borrelia garinii sp. nov., and group VS461 associated with Lyme borreliosis. [My paper] G Baranton , D Postic , I Saint Girons , P Boerlin , J C Piffaretti , M Assous , P A Grimont We studied 48 Borrelia isolates that were associated with Lyme borreliosis or were isolated from ticks and identified three DNA relatedness groups by using the S1 nuclease method. The three DNA groups (genospecies) were associated with specific rRNA gene restriction patterns, protein electrophoresis patterns, and patterns of reactivity with murine monoclonal antibodies. Genospecies I corresponded to Borrelia burgdorferi sensu stricto since it contained the type strain of this species (strain ATCC 35210); this genospecies included 28 isolates from Europe and the United States. Genospecies II was named Borrelia garinii sp. nov. and included 13 isolates from Europe and Japan. Genospecies III (group VS461) included seven isolates from Europe and Japan. Mesh-terms: Antibodies, Monoclonal; Bacterial Proteins, chemistry; Borrelia burgdorferi; Borrelia burgdorferi Group, classification; Borrelia burgdorferi Group, genetics; Borrelia burgdorferi Group, immunology; Borrelia, classification; Borrelia, genetics; Borrelia, immunology; DNA, Bacterial, chemistry; DNA, Ribosomal, chemistry; DNA, Ribosomal, genetics; Electrophoresis, Polyacrylamide Gel; Human; Lyme Disease, microbiology; Polymorphism, Restriction Fragment Length; RNA, Bacterial, genetics; RNA, Ribosomal, genetics;
Mol Microbiol. 1989 Apr ;3 (4):479-86 2761388 [Cited: 85] Molecular analysis of linear plasmid-encoded major surface proteins, OspA and OspB, of the Lyme disease spirochaete Borrelia burgdorferi. [My paper] S Bergstr�m , V G Bundoc , A G Barbour The ospA and ospB genes encode the major outer membrane proteins of the Lyme disease spirochaete Borrelia burgdorferi. The deduced translation products from the ospA and ospB genes were: (OspA) 273 amino acids long with a molecular weight of 29,334, and (OspB) 296 amino acids long with a molecular weight of 31,739. The two Osp proteins showed a great degree of sequence similarity indicating a recent evolutionary event. Molecular analysis and sequence comparison of OspA and OspB with other proteins revealed a sequence similarity to the signal peptides of prokaryotic lipoproteins. These are the first sequences from Borrelia and provide interesting data on the evolutionary relationship between spirochaetes and other species as well as providing potential for spirochaete diagnostics and vaccines. Mesh-terms: Amino Acid Sequence; Amino Acids, analysis; Bacterial Outer Membrane Proteins, biosynthesis; Bacterial Outer Membrane Proteins, genetics; Base Sequence; Borrelia, genetics; Cloning, Molecular; Codon; Comparative Study; DNA, Bacterial; Genes, Bacterial; Genes, Structural; Molecular Sequence Data; Operon; Plasmids; Recombinant Proteins, biosynthesis; Recombinant Proteins, genetics; Restriction Mapping; Support, Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.;
Science. 1987 Jul 24;237 (4813):409-11 3603026 [Cited: 82] Linear plasmids of the bacterium Borrelia burgdorferi have covalently closed ends. [My paper] A G Barbour , C F Garon The genetics of spirochetes, a division of eubacteria, has been little studied. Double-stranded linear plasmids were found in Borrelia burgdorferi, the agent of Lyme disease. A 49-kilobase linear plasmid contained the ospA and ospB genes, which encode the major outer membrane proteins of strain B31. Molecules of the 49-kilobase plasmid rapidly reannealed after alkaline denaturation; rapid renaturation was prevented if the 49-kilobase plasmids were first treated with S1 nuclease. When denatured plasmid molecules were examined directly, single-stranded circles of approximately 100-kilobase circumference were seen. These studies provide direct visual evidence that the linear plasmids have covalently closed ends. This form of DNA occurs in some animal viruses, but it has not heretofore been described in prokaryotic organisms. Mesh-terms: Bacterial Outer Membrane Proteins, genetics; Borrelia, genetics; DNA, Single-Stranded, genetics; DNA, Single-Stranded, ultrastructure; Genes, Bacterial; Genes, Structural; Microscopy, Electron; Plasmids; Support, U.S. Gov't, P.H.S.;
J Infect Dis. 1985 Sep ;152 (3):478-84 2411827 [Cited: 81] Heterogeneity of major proteins in Lyme disease borreliae: a molecular analysis of North American and European isolates. [My paper] A G Barbour , R A Heiland , T R Howe We examined 46 isolates of Borrelia burgdorferi, the etiologic agent of Lyme disease and related disorders, with polyacrylamide gel electrophoresis and monoclonal antibodies. Our attention was on the OspA proteins, which are major proteins of the spirochete. There were at least four discernible phenotypes of the OspA protein. While 25 North American isolates were, with one exception, homogeneous in the type of OspA protein that they produced, 21 European isolates were heterogeneous in the types of OspA proteins represented. Only three European strains resembled North American strains in their OspA phenotype. Application of a deoxyribonucleic acid probe for an ospA gene demonstrated that the arrangement of ospA-associated sequences in the DNA differed between isolates. Mesh-terms: Antibodies, Monoclonal; Antigens, Bacterial, immunology; Bacterial Outer Membrane Proteins, analysis; Bacterial Outer Membrane Proteins, genetics; Bacterial Outer Membrane Proteins, immunology; Base Sequence; Borrelia, analysis; Borrelia, genetics; Borrelia, immunology; Borrelia, isolation & purification; Comparative Study; DNA, Bacterial; Electrophoresis, Polyacrylamide Gel; Epitopes, immunology; Europe; Genes, Bacterial; Human; Lyme Disease, microbiology; Molecular Weight; Nucleic Acid Hybridization; Phenotype; United States;
J Clin Microbiol. 1988 Mar ;26 (3):475-8 3356787 [Cited: 79] Plasmid analysis of Borrelia burgdorferi, the Lyme disease agent. [My paper] A G Barbour A simple procedure for extraction of plasmid-enriched DNA from borreliae was used in a plasmid analysis of 13 strains of the Lyme disease agent, Borrelia burgdorferi. The extracted DNA was subjected to low-percentage agarose gel electrophoresis and examined either directly by ethidium bromide staining or after hybridization of the plasmids in situ with a DNA probe for the gene encoding the major outer membrane protein OspA. Each isolate had four to seven discernible plasmids of various sizes. Only 2 of the 13 strains had the same plasmid profile. The ospA gene probe hybridized to large plasmids to strains from both North America and Europe. A strain which had been passaged many times was found to have lost two of the six plasmids originally present. These findings indicate the potential usefulness of plasmid analysis as a strain-typing procedure and for identifying possible plasmid-conferred virulence factors. Mesh-terms: Bacterial Outer Membrane Proteins, genetics; Borrelia, classification; Borrelia, genetics; DNA, Bacterial, analysis; Electrophoresis, Agar Gel; Genes, Bacterial; Nucleic Acid Hybridization; Plasmids; Sequence Homology, Nucleic Acid; Support, U.S. Gov't, P.H.S.;
Proc Natl Acad Sci U S A. 1989 Aug ;86 (15):5969-73 2762306 [Cited: 55] Megabase-sized linear DNA in the bacterium Borrelia burgdorferi, the Lyme disease agent. [My paper] M S Ferdows , A G Barbour Using pulsed-field gel electrophoresis we examined the genome of Borrelia burgdorferi, a eubacterium of the spirochete phylum and the agent of Lyme disease. A population of this species' cells was lysed in situ in agarose blocks. An abundant DNA form that behaved as a linear duplex molecule under different electrophoretic conditions was found. The estimated size of the molecule was 950 kilobases. DNA from two other genera of spirochetes did not enter the gel under these conditions. These studies indicate that Borrelia spirochetes, perhaps uniquely among prokaryotic organisms, have linear chromosomes. Mesh-terms: Borrelia, genetics; Borrelia, pathogenicity; Centrifugation, Density Gradient, methods; DNA, Bacterial, genetics; DNA, Bacterial, isolation & purification; DNA, Bacterial, radiation effects; Electrophoresis, Agar Gel, methods; Electrophoresis, Gel, Two-Dimensional, methods; Ethidium, pharmacology; Human; Lyme Disease, microbiology; Molecular Weight; Nucleic Acid Hybridization; Support, U.S. Gov't, Non-P.H.S.; Support, U.S. Gov't, P.H.S.; Thymidine, metabolism; Tritium; Ultraviolet Rays;
Nature. ;318 (6043):257-63 4069202 [Cited: 54] Transposition of structural genes to an expression sequence on a linear plasmid causes antigenic variation in the bacterium Borrelia hermsii. [My paper] R H Plasterk , M I Simon , A G Barbour In Borrelia hermsii, a spirochaete that causes relapsing fever, the switch between expression of two frequent variable major protein (VMP) types (7 and 21) is associated with a DNA rearrangement. Both cell types 7 and 21 contain untranscribed 7 and 21 VMP genes on linear plasmids. The serotype 7 cells contain an additional copy of the 7 VMP gene fused to an expression sequence on another linear plasmid. Switching to the 21 serotype involves removal of the transcribed 7 VMP gene and fusion of a copy of the 21 VMP gene to this same expression sequence. Thus recombination between linear plasmids can activate different VMP genes. Mesh-terms: Bacterial Proteins, genetics; Bacterial Proteins, immunology; Base Sequence; Borrelia, genetics; Genes, Structural; Plasmids; Recombination, Genetic; Support, Non-U.S. Gov't; Support, U.S. Gov't, Non-P.H.S.; Variation (Genetics);
Cell. 1985 Jun ;41 (2):403-9 2580643 [Cited: 49] Antigenic variation is associated with DNA rearrangements in a relapsing fever Borrelia. [My paper] J T Meier , M I Simon , A G Barbour Borrelia hermsii, an agent of relapsing fever, undergoes antigenic variation in its host. Surface-exposed proteins with differing primary structures determine the serotype of each organism. Using amino acid sequence data from two of these variable proteins, we synthesized two mixed-sequence oligonucleotides and then used the oligonucleotides to probe mRNA and DNA of three isogenic serotypes of B. hermsii. In Northern blots the probes were specific for the mRNA of the homologous serotype. Southern blots revealed two classes of hybridizing fragments: those common to the three serotypes and those specific for a particular serotype. A serotype-specific DNA fragment, which had hybridized to both oligonucleotide probes, was cloned. Subsequent use of the cloned fragment as a probe provided further evidence that antigenic variation in B. hermsii is associated with DNA rearrangements and with occurrence of expression-linked copies of all, or part, of an antigen-specifying gene. Mesh-terms: Antigens, Bacterial, genetics; Antigens, Bacterial, immunology; Base Sequence; Borrelia, classification; Borrelia, genetics; Borrelia, immunology; Cloning, Molecular; DNA Restriction Enzymes; DNA, Bacterial; Epitopes, immunology; Nucleic Acid Hybridization; Oligodeoxyribonucleotides; Oligoribonucleotides; RNA, Bacterial; RNA, Messenger; Serotyping; Support, U.S. Gov't, Non-P.H.S.;
J Bacteriol. 1993 Feb ;175 (4):926-32 7679385 [Cited: 42] Transcriptional analyses and mapping of the ospC gene in Lyme disease spirochetes. [My paper] R T Marconi , D S Samuels , C F Garon In Lyme disease spirochetes, the ospC gene encodes a 22.7-kDa protein referred to as either the pC or the OspC protein. Using a variety of electrophoretic approaches followed by Southern blotting and probing with oligonucleotide probes, we mapped the ospC gene to a circular 26-kb plasmid. The ospC gene represents the first gene to be mapped to a circular plasmid in Lyme disease spirochetes. The occurrence of this gene in isolates belonging to each of the three Lyme disease-associated species, Borrelia burgdorferi, Borrelia garinii, and the VS461 group, was evaluated. The ospC gene was found to occur in all 21 isolates tested from each of the three species. Differential hybridization with a series of ospC probes in both Northern (RNA) and Southern blot analyses demonstrated that there is sequence variability in the ospC gene among isolates. While the gene was found to be present in all isolates, not all actively transcribed the gene. Transcriptional start site analyses suggest that the gene may be under the control of multiple promoters that are highly similar in nucleotide sequence. Mesh-terms: Bacterial Outer Membrane Proteins; Bacterial Proteins, genetics; Base Sequence; Borrelia, genetics; Chromosome Mapping; DNA, Bacterial, genetics; Gene Expression Regulation, Bacterial; Genes, Structural, Bacterial; Lyme Disease, microbiology; Molecular Sequence Data; Oligodeoxyribonucleotides, chemistry; Plasmids; Promoter Regions (Genetics); RNA, Bacterial, genetics; RNA, Messenger, genetics; Transcription, Genetic;
-------------------- Do unto others as you would have them do unto you. Remember Iam not a Doctor Just someone struggling like you with Tick Borne Diseases.
treepatrol
Honored Contributor (10K+ posts)
Member # 4117
posted
-------------------- Do unto others as you would have them do unto you. Remember Iam not a Doctor Just someone struggling like you with Tick Borne Diseases.
The Lyme Disease Network is a non-profit organization funded by individual donations. If you would like to support the Network and the LymeNet system of Web services, please send your donations to:
The
Lyme Disease Network of New Jersey 907 Pebble Creek Court,
Pennington,
NJ08534USA http://www.lymenet.org/
UBBFriend: Email this page to someone!
Printer-friendly view of this topic