Borrelia burgdorferi, the cause of Lyme Disease
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"It is not the strongest of the species that survives, nor the most intelligent, but rather the one most responsive to change." - Charles Darwin

As noted in the "Classification section", Borrelia burgdorferi are highly motile due to their periplasm flagella, which are located between the cytoplasmic membrane and outer membrane.    While the location of the flagella root is unique in B. burgdorferi, the flagella rotates a lot like the general rotation of any bacterial flagella -  it has a "hook" that spins on its axis. The location of the flagella is what sets B. burgdorferi apart from other bacteria.  Because it is between two membranes, it is able to "drive the rest of the cell around the long axis" which produces a motion that allows it to "drill" through tissues to invade its host (Coburn, J. & Kalish, R., 2000).  Generally, B. burgdorferi has around seven to eleven flagella all of which allow the bacteria to "screw drive" itself through host tissue.  This adaptation has allowed Borrelia burgdorferi to be an effective parasite and has greatly enhanced its mobility. 

It is understood that in order for the B. burgdorferi to survive and thrive, it must adapt to the temperature, acidic levels, and other conditions of its hosts.  The existence of the B. burgdorferi is dependent upon it sensing its surrounding and producing specific proteins in order to counteract conditions it may experience while living in its tick or mammal host. photo

For example, B. burgdorferi produce a lipid protein combination found on the outer membrane called  OspA (model on left).  This lipoprotien acts as the anchor for B.burgdorferi to attach within the midgut of the tick.  OspA allows B. burgdorferi to remain in the gut while the tick digests blood meal.  This adaptation is necessary to ensure that this bacteria species isn't digested along with the blood meal.  However, at the same time, decreasing in production of OspA allows B. burgdorferi to detach from the gut and therefore infect the rest of the tick's body, moving toward the salivary glands. This is when  B. burgdorferi senses the need for the production of OspC protein because OspC assists the bacteria in moving from the gut to the salivary glands  (Girschick, H., & Singh, S., 2004). Additionally, B. burgdorferi produces heat shock proteins which assist with changes in temperature and also act as chaperones, which assist organisms in the preservation of their molecular structure while changing environments.  A slime layer also coats the outer wall of B. burgdorferi allowing it to avoid digestion.  Therefore, it is evident that  B. burgdorferi needs to adapt to its specific environment and does so by producing specialized proteins.  

B. burgdorferi makes adjustments to its outer wall which senses changes in its surroundings and in return it communicates the changes that need to be made.  In response the genes activate and deactivate proteins of  B. burgdorferi's outer surface accordingly. Osps and heat shock proteins are essential for the survival of  B. burgdorferi.  Additionally, because a significant portion of B. burgdorferi is located on linear and circular plasmids, the organisms is able to adapt easily to various environments and also can avoid being destroyed by the hosts immune system (Schnarr, S., Franz, J., Krause, A., & Zeidler, H., 2006). 

Why is it so successful at adapting to its environment?

The uniqueness of B. burgdorferi's chromosomes is thought to greatly contribute to its ability to shift its outer proteins when the environment changes. B. burgdorferi has proven to be one of the few bacteria that have linear chromosomes (as apposed to circular) and also uncoiled plasmids.  These plasmids contain duplicated genes which allows B. burgdorferi to change its outer protein sequence in response to its hosts' defense systems.  It is also thought that this allows the organism to educe symptoms within hosts (Karlen, A., 2000)