- About
the Lyme Disease Bacterium
The causative
agent, Borrelia burgdorferi, is a type of spirochete.
Spirochetes are long, thin, spiral-shaped bacteria. Other spirochetes
include the causative agents of syphilis, relapsing fever, and
gum disease.
The bacterium
is thousands of times larger than a virus. However, it still
requires a powerful microscope to see one. Roughly 1,500 Bb
must be laid end to end to equal one inch. About 100,000 of Bb
laid side to side would equal one inch.
When Bb
was first discovered in 1982 it was thought that there was just
one strain. Since then, about 100 U.S. and 300 worldwide strains
of the bacterium have been discovered.
In the mid-1990's
genospecies were formed to group the many variations into subcategories.
" Borrelia
burgdorferi sensu lato" is name given to the overall
category. In North America there is just one genospecies variant
- Bb sensu stricto. In Europe there are three categories
Bb sensu stricto, B. garinii, and B. afzelii. Asia
has B. garinii and B. afzelii. Japan has B.
japonica and B. miyamoto. These groups are evolving
as new research discoveries occur.
A new pathogen
causing Lyme or "Lyme-like" disease has been reported.
While not culturable, it has been named B. lonestari sp.
The bacterium
is able to move around the body through the bloodstream and between
tissue. It can also invade tissue, replicate, and leave the cell
- destroying the cell as it emerges. Sometimes, as the bacterium
emerges, the cell wall collapses around the bacterium, forming
a "cloaking device". This action may aid the bacteria's
ability to hide from the immune system response.
Next: Where did Lyme Disease Come From?
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How is Lyme Disease Treated?
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