User:Smneu/sandbox

Borrelia is a genus of bacteria of the spirochete phylum.[1] It causes borreliosis, a zoonotic, vector-borne disease transmitted primarily by ticks and lice, depending on the species  of bacteria .[2] The genus is named after the French biologist Amédée Borrel (1867–1936)  who first documented the distinction between a species of Borrelia, B. anserina, (citation 3 from original article) and the other known type of spirochete at the time, Treponema pallidum .[3] ''' This bacteria must be viewed using dark field microscopy, which make the cells appear white against a dark background. Borrelia is grown in a medium called Barbour-Stoenner-Kelly (BSK) medium.  There are 52 known species of Borrelia; 21 are members of the Lyme disease group, 29 belong to the relapsing fever group, and two are members of a  genetically distinct  third group  typically found in reptiles .[3]  The Lyme disease group has been moved to their own genus, Borelliella, but this change is not yet widely accepted.  (also citation 3 in original article)  This bacteria uses hard and soft ticks and lice as vectors.   Testing for the presence of the bacteria in a human includes two-tiered serological testing, including immunoassays and immunoblotting. '''

Contents

 *  Biology 
 * 1 Phylogeny
 *  Vectors 
 * 2 Lyme disease
 * 3 Relapsing fever
 *  Pathobiology 
 * 4 References
 * 5 Further reading
 * 6 External links

Biology
They are a member of the Spirochaetacaea family and therefore present the characteristic spirochete (spiral) shape. Most species of Borrelia are obligate anaerobes, although there are some that are aerotolerant. Borrelia has an outer membrane that contains a substance similar to lipopolysaccharides, an inner membrane, and a layer of peptidoglycan in a periplasmic space, which classifies them as Gram-negative. However, this result is not easily visualized using Gram staining. Borrelia are typically 20-30 um long and 0.2-0.3 um wide.

Spirochetes move using axial filaments called endoflagella in their periplasmic space. The filaments rotate in this space, between the outer membrane and the peptidoglycan layer, propelling the bacterium forward in a corkscrew-like motion. The outer membrane of Borrelia contains outer surface proteins (Osp) that play a role in its virulence.

Phylogeny
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) [4] and National Center for Biotechnology Information (NCBI)[5] and the phylogeny is based on 16S rRNA-based LTP release 111 by 'The All-Species Living Tree' Project.[6]

(phylogenic tree is too clunky in my sandbox so I didn't paste it)

''' There are only 46 species listed on the side of the page, but there are 52 known species - figure out which ones are missing. '''

 B. mayonii Pritt et al. 2016 

Vectors
Ticks

Hard ticks of the genus Ixodidae are common vectors of Borellia bacteria and are the only type of ticks that have been shown to transmit Lyme disease bacteria to humans. Other species are carried by soft ticks. The soft tick Ornithodoros carries the species of Borellia that cause relapsing fever. Another species, B. anserina is carried by the soft tick Argas. (citation 3 in original article) Inside the ticks, the bacteria grows in the midgut and then travels to the salivary glands to be transmitted to a new host. Ticks can spread the bacteria to each other when co-feeding. If an animal has been infected by a tick and then is bit by a second tick, the second tick can become infected. The bacteria is most commonly transmitted to humans through ticks in the nymph stage of development, because they are smaller and less likely to be noticed and removed. The ticks must have around 36 to 48 hours of contact with a host in order to successfully transmit the bacteria.

Lice

Lice that feed on infected humans acquire the Borrelia organisms that then multiply in the  hemolymph and gut  of the louse. When an infected louse feeds on an uninfected human, the organism gains access when the victim crushes the louse or scratches the area where the louse is feeding. The Center for Disease Control reported that there is no credible evidence that lice can carry Borrelia.

Lyme disease
Main article: Lyme disease microbiology

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Of the 52 known species of Borrelia,  21  are known to cause Lyme disease or borreliosis and are transmitted by ticks  (citation 3 in original article) . The major Borrelia species causing Lyme disease are Borrelia burgdorferi, Borrelia afzelii, and Borrelia garinii. All species that cause Lyme disease are referred to collectively as B. burgdorferi sensu lato, while B. burgdorferi itself is specified as B. burgdorferi senso stricto. B. burgdorferi was previously believed to be the only species to cause Lyme disease in the US, with the other two existing only in Europe and Asia, but a new species called B. mayonii has caused Lyme disease in the US as well.

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Relapsing fever
Main article: Relapsing fever

Relapsing fever  (RF)  borreliosis often occurs with severe bacteremia.[8]  There are 25 species of Borrelia that are known to cause relapsing fever  ' While most species use the soft tick Argasidae'' as their vector, there are some outliers that live in hard ticks or lice.   Relapsing fever can be spread epidemically through lice or endemically through ticks. '''

B. recurrentis,   a common species underlying relapsing fever,  is transmitted by the human body louse; no other animal reservoir of B. recurrentis is known. B. recurrentis infects the person via mucous membranes and then invades the bloodstream.

Other tick-borne relapsing infections are acquired from other species, such as B. hermsii, B. parkeri, or B. miyamotoi,  ([9] this citation in the original article is wrong)  which can be spread from rodents, and serve as a reservoir for the infection, via a tick vector  + cit . B. hermsii and B. recurrentis cause very similar diseases, although the disease associated with B. hermsii has more relapses and is responsible for more fatalities, while the disease caused by B. recurrentis has longer febrile and afebrile intervals and a longer incubation period  + cit .

Diagnosis
Direct tests include culture of Borrelia from skin, blood, or cerebrospinal fluid (CSF) and detection of genetic material by polymerase chain reaction in skin, blood, or synovial fluid. Two-tiered serological testing is performed for differential diagnosis of Borrelia infection. The first-tier tests detect specific antibodies (IgM and IgG together or separately) and include enzyme immunoassays (e.g. ELISAs) and immunofluorescent assays. Positive results for first-tier tests are confirmed using second-tier testing. The second-tier consists of standardized immunoblotting, either by using Western blots or blots striped with diagnostically-important purified antigens. Positive results for second-tier tests are confirmatory for the presence of Borrelia infection. [7] ''' Spirochetes can also be visualized using Wright-stained blood smears. '''