scholarly journals Telomere Exchange between Linear Replicons of Borrelia burgdorferi

2004 ◽  
Vol 186 (13) ◽  
pp. 4134-4141 ◽  
Author(s):  
Wai Mun Huang ◽  
Margaret Robertson ◽  
John Aron ◽  
Sherwood Casjens
Keyword(s):  
Borrelia Burgdorferi ◽  
Large Fraction ◽  
Genetic Material ◽  
Linear Plasmid ◽  
Large Chromosome ◽  
Evolutionary Time ◽  
Linear Plasmids ◽  
Nonhomologous Recombination ◽  
Natural Isolates ◽  
The Right

ABSTRACT Spirochetes in the genus Borrelia carry a linear chromosome and numerous linear plasmids that have covalently closed hairpin telomeres. The overall organization of the large chromosome of Borrelia burgdorferi appears to have been quite stable over recent evolutionary time; however, a large fraction of natural isolates carry differing lengths of DNA that extend the right end of the chromosome between about 7 and 20 kbp relative to the shortest chromosomes. We present evidence here that a rather recent nonhomologous recombination event in the B. burgdorferi strain Sh-2-82 lineage has replaced its right chromosomal telomere with a large portion of the linear plasmid lp21, which is present in the strain B31 lineage. At least two successive rounds of addition of linear plasmid genetic material to the chromosomal right end appear to have occurred at the Sh-2-82 right telomere, suggesting that this is an evolutionary mechanism by which plasmid genetic material can become part of the chromosome. The unusual nonhomologous nature of this rearrangement suggests that, barring horizontal transfer, it can be used as a unique genetic marker for this lineage of B. burgdorferi chromosomes.

scholarly journals Conservation of Plasmid Maintenance Functions between Linear and Circular Plasmids in Borrelia burgdorferi

2003 ◽  
Vol 185 (10) ◽  
pp. 3202-3209 ◽  
Author(s):  
Philip E. Stewart ◽  
George Chaconas ◽  
Patricia Rosa
Keyword(s):  
Borrelia Burgdorferi ◽  
Linear Plasmid ◽  
Linear Plasmids ◽  
Autonomous Replication ◽  
Plasmid Maintenance ◽  
Disease Agent ◽  
Mammalian Infection ◽  
Lyme Disease Agent ◽  
Paralogous Gene Family ◽  
Derivatives Of

ABSTRACT The Lyme disease agent Borrelia burgdorferi maintains both linear and circular plasmids that appear to be essential for mammalian infection. Recent studies have characterized the circular plasmid regions that confer autonomous replication, but the genetic elements necessary for linear plasmid maintenance have not been experimentally identified. Two vectors derived from linear plasmids lp25 and lp28-1 were constructed and shown to replicate autonomously in B. burgdorferi. These vectors identify internal regions of linear plasmids necessary for autonomous replication in B. burgdorferi. Although derived from linear plasmids, the vectors are maintained in circular form in B. burgdorferi, indicating that plasmid maintenance functions are conserved, regardless of DNA form. Finally, derivatives of these vectors indicate that paralogous gene family 49 is apparently not required for either circular or linear plasmid replication.

scholarly journals Distribution of Twelve Linear Extrachromosomal DNAs in Natural Isolates of Lyme Disease Spirochetes

2000 ◽  
Vol 182 (9) ◽  
pp. 2476-2480 ◽  
Author(s):  
Nanette Palmer ◽  
Claire Fraser ◽  
Sherwood Casjens
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Type Strain ◽  
Sensu Stricto ◽  
Linear Plasmids ◽  
Borrelia Garinii ◽  
Natural Isolates ◽  
Disease Agent ◽  
Lyme Disease Agent ◽  
Sequence Similarities

ABSTRACT We have analyzed a panel of independent North American isolates of the Lyme disease agent spirochete, Borrelia burgdorferi (sensu stricto), for the presence of linear plasmids with sequence similarities to the 12 linear plasmids present in theB. burgdorferi type strain, isolate B31. The frequency of similarities to probes from each of the 12 B31 plasmids varied from 13 to 100% in the strain panel examined, and these similarities usually reside on plasmids similar in size to the cognate B31 plasmid. Sequences similar to 5 of the 12 B31 plasmids were found in all of the isolates examined, and >66% of the panel members hybridized to probes from 4 other plasmids. Sequences similar to most of the B. burgdorferi B31 plasmid-derived DNA probes used were also found on linear plasmids in the related Eurasian Lyme agentsBorrelia garinii and Borrelia afzelii; however, some of these plasmids had uniform but substantially different sizes from their B. burgdorferi counterparts.

Linear plasmids in Klebsiella and other Enterobacteriaceae

2021 ◽  
Author(s):  
Jane Hawkey ◽  
Hugh Cottingham ◽  
Alex Tokolyi ◽  
Ryan R Wick ◽  
Louise M Judd ◽  
...  
Keyword(s):  
Plasmid Stability ◽  
Bacterial Species ◽  
Salmonella Typhi ◽  
Multidrug Resistant ◽  
Linear Plasmid ◽  
Extrachromosomal Dna ◽  
Linear Plasmids ◽  
Future Studies ◽  
And Function

Linear plasmids are extrachromosomal DNA that have been found in a small number of bacterial species. To date, the only linear plasmids described in the Enterobacteriaceae family belong to Salmonella, first found in Salmonella Typhi. Here, we describe a collection of 12 isolates of the Klebsiella pneumoniae species complex in which we identified linear plasmids. We used this collection to search public sequence databases and discovered an additional 74 linear plasmid sequences in a variety of Enterobacteriaceae species. Gene content analysis divided these plasmids into five distinct phylogroups, with very few genes shared across more than two phylogroups. The majority of linear plasmid-encoded genes are of unknown function, however each phylogroup carried its own unique toxin-antitoxin system and genes with homology to those encoding the ParAB plasmid stability system. Passage in vitro of the 12 linear plasmid-carrying Klebsiella isolates in our collection (which include representatives of all five phylogroups) indicated that these linear plasmids can be stably maintained, and our data suggest they can transmit between K. pneumoniae strains (including members of globally disseminated multidrug resistant clones) and also between diverse Enterobacteriaceae species. The linear plasmid sequences, and representative isolates harbouring them, are made available as a resource to facilitate future studies on the evolution and function of these novel plasmids.

scholarly journals Normal pressure hydrocephalus secondary to Lyme disease, a case report and review of seven reported cases

BMC Neurology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Louise Nørreslet Gimsing ◽  
Anne-Mette Hejl
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Normal Pressure Hydrocephalus ◽  
Chronic Phase ◽  
Normal Pressure ◽  
Ventricular System ◽  
One Year ◽  
The One ◽  
The Right ◽  
Balance Problems

Abstract Background Infection with tick borne Borrelia Burgdorferi (Lyme disease) can without treatment rarely develop into a chronic phase. Secondary Normal Pressure Hydrocephalus (sNPH) based on chronic infection with Borrelia Burgdorferi (Bb) is an even rarer entity, that with the right treatment is potentially curable. Case presentation A 67-year-old male with a slow onset of progressive balance problems, also presented unspecified dizziness, urge feeling, neck soreness and discrete cognitive complaints. An MRI scan revealed an enlarged ventricular system compatible with NPH. After further liquor dynamic procedures, cerebrospinal fluid (CSF) was analysed with the surprising results of lymphocytic pleocytosis, and signs of increased antibody production. Microbiology revealed chronic neuroborreliosis and the patient was treated with antibiotics accordingly. At the one-year follow-up no symptoms remained and the ventricular system almost normalized. Conclusions We describe the 7th published case of sNPH secondary to chronic Borreliosis in a previous healthy adult. Existing published literature has been reviewed and previous cases showed similarly nearly full clinical recovery. Primary/idiopathic NPH (iNPH) is treated with the surgical intervention of ventriculoperitoneal shunt and can be mistaken for a sNPH. The awareness of rare causes of sNPH like chronic Borreliosis is important as it is easily treated non surgically.

Privacy: Potential Violations of Human Dignity

2019 ◽  
Vol 32 (2) ◽  
pp. 106-107
Author(s):  
Constance L. Milton
Keyword(s):  
Human Dignity ◽  
Gene Editing ◽  
Personal Information ◽  
Genetic Material ◽  
Privacy Concerns ◽  
The Right ◽  
Genetic Structures

Privacy has been understood as a bioethical concept whose focus is on personal choosing or the right to control access to self. In nursing, privacy concerns abound where there is potential for the violation of human dignity as scientific advancements in genetic biotechnology potentially disclose personal information and genetic structures are made known to others without the consent of persons whose genetic material is being utilized for biological experimentation. In this article, the author offers new insights into the concept of privacy and human dignity as gene editing and its possible consequences unfurl within the scientific and healthcare arenas. A humanbecoming ethos perspective for nursing is illuminated.

scholarly journals Right Place at the Right Time: How Changes in Protocadherins Affect Synaptic Connections Contributing to the Etiology of Neurodevelopmental Disorders

Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2711
Author(s):  
Maria Mancini ◽  
Silvia Bassani ◽  
Maria Passafaro
Keyword(s):  
Cell Adhesion ◽  
Neurodevelopmental Disorders ◽  
Synapse Formation ◽  
Large Fraction ◽  
Critical Role ◽  
Basic Research ◽  
Axon Pathfinding ◽  
Neurite Initiation ◽  
The Right

During brain development, neurons need to form the correct connections with one another in order to give rise to a functional neuronal circuitry. Mistakes during this process, leading to the formation of improper neuronal connectivity, can result in a number of brain abnormalities and impairments collectively referred to as neurodevelopmental disorders. Cell adhesion molecules (CAMs), present on the cell surface, take part in the neurodevelopmental process regulating migration and recognition of specific cells to form functional neuronal assemblies. Among CAMs, the members of the protocadherin (PCDH) group stand out because they are involved in cell adhesion, neurite initiation and outgrowth, axon pathfinding and fasciculation, and synapse formation and stabilization. Given the critical role of these macromolecules in the major neurodevelopmental processes, it is not surprising that clinical and basic research in the past two decades has identified several PCDH genes as responsible for a large fraction of neurodevelopmental disorders. In the present article, we review these findings with a focus on the non-clustered PCDH sub-group, discussing the proteins implicated in the main neurodevelopmental disorders.

scholarly journals The Absence of Linear Plasmid 25 or 28-1 of Borrelia burgdorferi Dramatically Alters the Kinetics of Experimental Infection via Distinct Mechanisms

2003 ◽  
Vol 71 (8) ◽  
pp. 4608-4613 ◽  
Author(s):  
Maria Labandeira-Rey ◽  
J. Seshu ◽  
Jonathan T. Skare
Keyword(s):  
Borrelia Burgdorferi ◽  
Experimental Infection ◽  
Humoral Response ◽  
Etiologic Agent ◽  
Immunoglobulin M ◽  
Linear Plasmid ◽  
Wild Type ◽  
Infection Period ◽  
Kinetics Of ◽  
Wild Type Parent

ABSTRACT The 25-kb linear plasmid lp25 and one of the 28-kb linear plasmids (lp28-1) are required for experimental infection in Borrelia burgdorferi, the etiologic agent of Lyme disease. The loss of these plasmids either eliminates infectivity (lp25) or significantly increases the 50% infective dose during a 2-week infection period (lp28-1). This study assessed the kinetics of bacterial dissemination in C3H/HeN mice infected with B. burgdorferi lacking either lp25 or lp28-1, as well as their wild-type parent, and tracked the development of specific borrelial antibodies over a 3-week period. The results indicated that the wild type and the lp28-1− strains were able to disseminate throughout the host, whereas the lp25− strain was cleared within 48 h of inoculation. While the wild-type B. burgdorferi persisted in tissues for the duration of the study, the lp28-1− mutant began clearing at day 8, with no detectable bacteria present by day 18. As expected, the wild-type strain persisted in C3H/HeN mice despite a strong humoral response; however, the lp28-1− mutant was cleared coincidently with the development of a modest immunoglobulin M response. The lp28-1− mutant was able to disseminate and persist in C3H-scid mice at a level indistinguishable from that of wild-type cells, confirming that acquired immunity was required for clearance in C3H/HeN mice. Thus, within an immunocompetent host, lp28-1-encoded proteins are not required for dissemination but are essential for persistence associated with Lyme borreliosis.

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