Borrelia burgdorferi

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Francisella tularensis
Francisella tularensis 01.jpg
F. tularensis colonies on an agar plate
Scientific classification e
Domain: Bacteria
Phylum: Spirochaetes
Order: Spirochaetales
Family: Spirochaetaceae
Genus: Borrelia
Species: B. burgdorferi
Binomial name
Borrelia burgdorferi
Johnson et al. 1984 emend. Baranton et al. 1992

Borrelia burgdorferi is a bacterial species of the spirochete class of the genus Borrelia. B. burgdorferi exists in North America and Europe and is the predominant causative agent of Lyme disease. Borrelia species are considered diderm (double-membrane) bacteria rather than gram positive or negative.[1]

Pathology[edit]

Lyme disease is a zoonotic, vector-borne disease transmitted by the Ixodes tick (also the vector for Babesia); the causative agent is named after the researcher Willy Burgdorfer, who first isolated the bacterium in 1982.[2] B. burgdorferi is one of the few pathogenic bacteria that can survive without iron, having replaced all of its iron-sulfur cluster enzymes with enzymes that use manganese, thus avoiding the problem many pathogenic bacteria face in acquiring iron.[3]

Clinical presentation of Lyme disease may[4] include the characteristic bull's eye rash and erythema chronicum migrans (a rash which spreads peripherally and spares the central part), as well as myocarditis, cardiomyopathy, arrythmia, arthritis, arthralgia, meningitis, neuropathies and facial nerve palsy.

Characteristic "bull's eye" rash of Lyme disease

B. burgdorferi infections have been linked to non-Hodgkin lymphomas.[5][6]

Pathophysiology[edit]

Lyme disease, caused by "B. burdorferi from tick bites consist of 3 stages starting from initial bite. Stage 1: affects the area around the bite, there may be a rash or swelling. Stage 2 occurs weeks to months after, if still untreated the bacteria will be pushed further down into the body, it will start affecting the heart, bones, and nervous system. In Stage 3, occurs years after and you will develop chronic arthritis and neurological complications.[7]

Morphology[edit]

B. burgdorferi has been described as a novel spirochete. It resembles other spirochetes in that it is a highly specialized, motile, two-membrane, spiral-shaped bacterium that lives primarily as an extracellular pathogen. While only 0.2 to 0.3 micrometers wide, the cell length may exceed 15 to 20 micrometers.

B. burgdorferi is an anaerobic, motile spirochete with 7-11 bundled perisplasmic flagella set at each end that allow the bacterium to move in low and high viscosity media alike, which is related to its high virulence factor. [8]

Genetics[edit]

B. burgdorferi (B31 strain) was the third microbial genome ever sequenced, following the sequencing of both Haemophilus influenzae and Mycoplasma genitalium in 1995, and its linear chromosome contains 910,725 base pairs and 853 genes.[9] The sequencing method used was whole genome shotgun. The sequencing project, completed and published in Nature in 1997, was conducted at The Institute for Genomic Research.

See also[edit]

References[edit]

  1. ^ Samuels DS; Radolf, JD (editors) (2010). "Chapter 6, Structure, Function and Biogenesis of the Borrelia Cell Envelope". Borrelia: Molecular Biology, Host Interaction and Pathogenesis. Caister Academic Press. ISBN 978-1-904455-58-5. 
  2. ^ Burgdorfer W, Barbour AG, Hayes SF, Benach JL, Grunwaldt E, Davis JP (June 1982). "Lyme disease-a tick-borne spirochetosis?". Science 216 (4552): 1317–9. Bibcode:1982Sci...216.1317B. doi:10.1126/science.7043737. PMID 7043737. 
  3. ^ Galdwin, Mark; Trattler, Bill (2009). Spirochetes: Clinical Microbiology Made Ridiculously Simple. MedMaster, Inc. ISBN 978-0-940780-81-1. 
  4. ^ CDC. "Symptoms - Lyme Disease http://www.cdc.gov/lyme/signs_symptoms/". 
  5. ^ Guidoboni M, Ferreri AJ, Ponzoni M, Doglioni C, Dolcetti R (January 2006). "Infectious agents in mucosa-associated lymphoid tissue-type lymphomas: pathogenic role and therapeutic perspectives". Clinical Lymphoma & Myeloma 6 (4): 289–300. doi:10.3816/CLM.2006.n.003. PMID 16507206. 
  6. ^ Chang, A. H.; Parsonnet, J. (2010). "Role of Bacteria in Oncogenesis". Clinical Microbiology Reviews 23 (4): 837–857. doi:10.1128/CMR.00012-10. ISSN 0893-8512. 
  7. ^ Tilly, Rosa, Stewart, Kit. "Biology of Infection". http://www.ncbi.nlm.nih.gov/. 
  8. ^ Motaleb, Mohammed; Corum, Linda; Bono, James; Elias, Abdallah; Rosa, Patricia; Samuels, D. Scott; Charon, Nyles. "Borrelia burgdorferi periplasmic flagella have both skeletal and motility functions". NCBI. Proceedings of the National Academy of Sciences of the United States of America. Retrieved 10 May 2015. 
  9. ^ Fraser CM, Casjens S, Huang WM et al. (December 1997). "Genomic sequence of a Lyme disease spirochaete, Borrelia burgdorferi". Nature 390 (6660): 580–6. Bibcode:1997Natur.390..580F. doi:10.1038/37551. PMID 9403685. 

External links[edit]